CN205642284U

CN205642284U - Capacitive sensing device

Info

Publication number: CN205642284U
Application number: CN201620433620.9U
Authority: CN
Inventors: 汪际军
Original assignee: Qualper Optoelectronics Technology (shanghai) Co Ltd
Current assignee: Quanpu Semiconductor Technology (Shenzhen) Co., Ltd.
Priority date: 2016-05-12
Filing date: 2016-05-12
Publication date: 2016-10-12
Anticipated expiration: 2026-05-12

Abstract

A plurality of sensing circuit (310, 510) of (C01, C02) are organized in a capacitive sensing device (300) in a plurality of series capacitance including the coupling. Every electric capacity (C31, C41) in the series capacitance group (C02) has and sets up in a scanning board (40) or balanced ring (70 a) last movable electrode (431, 441) of one micro scanning ware (100, 200) and solid fixed electrode (131, 142) on setting up a lateral wall (30) of in a basement (10) a cavity (20). The deflection of scanning version (40) or balanced ring (70) leads to the change of series capacitance group (C01, C02) capacitance value. A plurality of magnitude of voltages of (C01, C02) electric capacity are organized in a plurality of sensing circuit (310, 510) output corresponding to series capacitance. The output signal of capacitive sensing device (300) is a feedback circuit provides the angle information of scanner (100, 200) throwing the laser beam.

Description

Capacitive sensing apparatus

Technical field

This utility model relates to a kind of sensing device, particularly relates to what a kind of angle displacement for micro scanner sensed Capacitive sensing apparatus.

Background technology

In the micro-projection arrangement of laser, MEMS micro scanning system (Micro Electronic Mechanical System, Microelectromechanical-systems) a usually twin shaft microelectromechanical-systems, the one scan plate of micro scanning system in scanning process along the first axle Rotate with a plurality of pixels in formation a line, and a balance ring rotates a plurality of to be formed along the second axle vertical with the first axle Pixel column, to project the projected light beam comprising image pixel information.In order to guarantee, the accuracy of output projected picture, adopts The laser signal sent LASER Light Source with optical sensor senses, and uses angle displacement sensor to scanning board and balance Ring angle displacement signal in rotation process senses, and above-mentioned sensing signal feeds back to MEMS micro scanning system The image signal modulation unit of system, the signal synchronization module of image signal modulation unit verifies projection picture according to feedback signal The concordance of Pixel Information.

Scanning board or the angle of balance ring rotation in the micro-projection arrangement of present laser, to MEMS micro scanner system The general employing of the sensing of displacement arranges the interior toggle being connected with balance ring, Yi Jiping on the scanning board both sides of micro scanning system The both sides of weighing apparatus ring arrange outer torsion arm with substrate junction, and interior toggle is orthogonal with outer torsion arm.By at interior torsion The lower section of arm and outer torsion arm arranges piezoelectric, and two toggles are produced in scanning board and balance ring rotation process Torsion, exports relevant voltage signal by piezoelectric effect.This voltage signal corresponding to scanning board and balance ring at the first axle and The angle displacement information that second axle rotates.

In MEMS micro scanning system, the toggle set by two rotary shafts limits scanning board to a certain extent And balance ring turning angle shifting, to such an extent as to the pixel size of impact projection output picture and the resolution of shown picture. Therefore, for further enhancing the resolution sizes of projection picture, can consider to cancel limiting scanning board and balance in design The toggle of ring turning angle shifting amplitude.Cancel toggle in MEMS micro scanning system to arrange, scanning dish or balance The angular displacement information that ring rotates along the first axle and the second direction of principal axis rotates then cannot sense by the way of piezoelectric effect.

For meeting the MEMS micro scanning system that is not only suitable for, scanning board or balance turn around the first axle and the second axle simultaneously During Dong, the projected light beam scanned and project can effectively be adjusted by micro scanner effectively, it is ensured that projected light beam Accuracy, proposing a kind of capacitive sensing apparatus being applicable to multiple applied environment is objective of the present utility model.

Summary of the invention

This utility model purpose is for providing a capacitive sensing apparatus, and described capacitive sensing apparatus is used for MEMS micro scanning Device (be called for short " micro scanner "), described capacitive sensing apparatus is to the scanning board of micro scanner and the rotation displacement of balance ring Carry out sensing and export a voltage sense signal.

According to this utility model one basic feature, described capacitive sensing apparatus is positioned at a micro scanner, described micro-sweeps Retouch utensil and have the one scan plate of the cavity being positioned at a substrate.Described cavity has the sidewall surrounding described scanning board. Described scanning board has a first surface and the second surface relative to described first surface.Described scanning board is set as ringing Answering a driving to rotate around one first axle and the one second axle rotation vertical with described first axle, described cavity has a sidewall.

According to another feature of the present utility model, described capacitive sensing apparatus includes one first electric capacity, one second electric capacity, One first electric conductor and one first sensing circuit.Described first electric capacity includes a movable electrode, is arranged at the of scanning board On one surface, it is positioned at one first limit of the first axle, and away from the first axle one distance.And a fixed electrode, it is arranged at base On the sidewall of bottom cavity body and adjacent to described movable electrode.Described movable electrode is static at scanning board with described fixed electrode or turns There is during Dong certain area coverage.Described second electric capacity includes a movable electrode, is arranged at the second table of scanning board On face, it is positioned at one second limit relative with the first limit of the first axle, and away from the first axle one distance.And a fixed electrode, Being arranged on the sidewall of substrate cavity and neighbouring described movable electrode, described movable electrode and described fixed electrode are at scanning board Static or rotation process has certain area coverage.

According to another feature of the present utility model, described first electric conductor is coupled in the movable electrode and of the first electric capacity The movable electrode of two electric capacity so that the first electric capacity and the second electric capacity constitute one first series capacitance group.Described first electric conductor May be disposed on first surface or the second surface of scanning board, or embed in described scanning board.

According to another feature of the present utility model, described first sensing circuit has a first input end, and one second is defeated Enter end and an outfan, described first input end and the second input are coupled respectively to the fixed electrode and second of the first electric capacity The fixed electrode of electric capacity.Described first sensing circuit is set as producing the capacitance corresponding to described first series capacitance group One first magnitude of voltage to outfan export.

According to another feature of the present utility model, described capacitive sensing apparatus also includes one the 3rd electric capacity and one the 4th electricity Hold, one second electric conductor and one second sensing circuit.Described 3rd electric capacity includes a movable electrode, is arranged at scanning board On first surface, it is positioned at the second limit of the first axle, and away from the first axle one distance.And a fixed electrode, it is arranged at base On the sidewall of bottom cavity body and adjacent to described movable electrode, described movable electrode is static at scanning board with described fixed electrode or turns There is during Dong certain area coverage.Described 4th electric capacity includes a movable electrode, is arranged at the second table of scanning board On face, it is positioned at the first limit of the first axle, and away from the first axle one distance.And a fixed electrode, it is arranged at substrate cavity Sidewall on and neighbouring described movable electrode, described movable electrode and described fixed electrode be static or rotation process at scanning board In there is certain area coverage.

According to another feature of the present utility model, described second electric conductor is coupled in the movable electrode and of the 3rd electric capacity The movable electrode of four electric capacity so that the 3rd electric capacity and the 4th electric capacity constitute one second series capacitance group.

According to another feature of the present utility model, described second sensing circuit has a first input end, and one second is defeated Enter end and an outfan, first input end and the second input are coupled respectively to fixed electrode and the 4th electric capacity of the 3rd electric capacity Fixed electrode.Described second sensing circuit is set as producing one of the capacitance corresponding to described second series capacitance group Second magnitude of voltage exports to outfan.

According to another feature of the present utility model, described capacitive sensing apparatus also includes one first differential amplifier circuit. Described first differential amplifier circuit has a first input end and one second input, and first input end is coupled in the first sensing The outfan of circuit, the second input is coupled in the outfan of the second sensing circuit.Described differential amplifier circuit is set as defeated Going out a magnitude of voltage, this magnitude of voltage corresponds to the first magnitude of voltage and the second magnitude of voltage.

According to another feature of the present utility model, described capacitive sensing apparatus is the second axial first of scanning board One the 3rd electric capacity and one the 4th electric capacity, one second electric conductor and one second sensing circuit it is also respectively provided with on limit and the second limit. Described 3rd electric capacity includes a movable electrode, is arranged on the first surface of scanning board, is positioned at one first limit of the second axle, And away from the second axle one distance.And a fixed electrode, it is arranged on the sidewall of substrate cavity and neighbouring described movable electrode, Described movable electrode and described fixed electrode be static at scanning board or has certain area coverage in rotation process.Described Four electric capacity include a movable electrode, are arranged on the second surface of scanning board, are positioned at the relative with described first limit of the second axle One second limit, and away from the second axle one distance.And a fixed electrode, it is arranged on the sidewall of substrate cavity and neighbouring Described movable electrode.Described movable electrode and described fixed electrode be static at described scanning board or has certain in rotation process Area coverage.

According to another feature of the present utility model, described second electric conductor is coupled in the movable electrode and of the 3rd electric capacity The movable electrode of four electric capacity so that the 3rd electric capacity constitutes one second series capacitance group with described 4th electric capacity.

According to another feature of the present utility model, described second sensing circuit has a first input end, and one second is defeated Enter end and an outfan, first input end and the second input are coupled respectively to fixed electrode and the 4th electric capacity of the 3rd electric capacity Fixed electrode.Described sensing circuit is set as producing one second of the capacitance corresponding to described 3rd series capacitance group Magnitude of voltage exports to outfan.

According to another feature of the present utility model, described capacitive sensing apparatus is the second axial second of scanning board One the 5th electric capacity and one the 6th electric capacity, one the 3rd electric conductor and one the 3rd sensing circuit it is also respectively provided with on limit and the first limit. Described 5th electric capacity includes a movable electrode, is arranged on the first surface of scanning board, is positioned at the second limit of the second axle, and Away from the second axle one distance.And a fixed electrode, it is arranged on the sidewall of substrate cavity and neighbouring described movable electrode, Described movable electrode and described fixed electrode be static at scanning board or has certain area coverage in rotation process.Described Six electric capacity include a movable electrode, are arranged on the second surface of scanning board, are positioned at the first limit of the second axle, and away from second Axle one distance.And a fixed electrode, it is arranged on the sidewall of substrate cavity and neighbouring described movable electrode.Described can Moving electrode and described fixed electrode be static at scanning board or has certain area coverage in rotation process.

According to another feature of the present utility model, described 3rd electric conductor is coupled in the movable electrode and of the 5th electric capacity The movable electrode of six electric capacity so that the 5th electric capacity and the 6th electric capacity constitute one the 3rd series capacitance group.

According to another feature of the present utility model, described 3rd sensing circuit has a first input end, and one second is defeated Enter end and an outfan.First input end and the second input are coupled respectively to fixed electrode and the 6th electric capacity of the 5th electric capacity Fixed electrode.Described 3rd sensing circuit is set as producing one of the capacitance corresponding to described 3rd series capacitance group Third voltage value exports to described outfan.

According to another feature of the present utility model, described capacitive sensing apparatus also includes one second differential amplifier circuit. Described second differential amplifier circuit has a first input end and one second input.Described first input end is coupled in second The outfan of sensing circuit, described second input is coupled in the outfan of the 3rd sensing circuit.Described differential amplifier circuit Being set as exporting a magnitude of voltage, described magnitude of voltage corresponds to the second magnitude of voltage and third voltage value.

According to another feature of the present utility model, described capacitive sensing apparatus also includes a balance ring, described balance ring It is positioned at the cavity of substrate and surrounds scanning board.Described balance ring have a first surface and relative to first surface one Two surfaces, and described balance ring is connected with scanning board by least one toggle.Wherein, scanning board is set as around being parallel to First axle of at least one toggle rotates, and described balance ring is set as that the second axle around being perpendicular to the first axle rotates.

According to another feature of the present utility model, described capacitive sensing apparatus includes that scanning board is first axial The first electric capacity on one side and arranged on the second limit and the second electric capacity, also include balancing ring the second axial first limit and with One the 3rd electric capacity arranged on the second limit that first limit is relative and one the 4th electric capacity, one second electric conductor and one second sensing electricity Road.Described 3rd electric capacity includes a movable electrode, is arranged on the first surface of balance ring, is positioned at the one first of the second axle Limit, and away from the second axle one distance.And a fixed electrode, be arranged on the sidewall of substrate cavity and neighbouring described movably Electrode.Described movable electrode and described fixed electrode be static at balance ring or has certain area coverage in rotation process. Described 4th electric capacity includes a movable electrode, is arranged on the second surface of balance ring, is positioned at the second limit of the second axle, and Away from the second axle one distance.And a fixed electrode, it is arranged on the sidewall of substrate cavity and neighbouring described movable electrode. Described movable electrode and described fixed electrode be static at balance ring or has certain area coverage in rotation process.

According to another feature of the present utility model, described second sensing circuit has a first input end, and one second is defeated Enter end and an outfan.First input end and the second input are coupled respectively to fixed electrode and the 4th electric capacity of the 3rd electric capacity Fixed electrode.Described sensing circuit is set as producing one second of the capacitance corresponding to described second series capacitance group Magnitude of voltage exports to outfan.

According to another feature of the present utility model, the balance ring of described capacitive sensing apparatus is second axial second One the 5th electric capacity and one the 6th electric capacity, one the 3rd electric conductor and one the 3rd sensing circuit it is additionally provided with on limit and the first limit.Institute State the 5th electric capacity and include a movable electrode, be arranged on the first surface of balance ring, be positioned at the second limit of the second axle, and away from Second axle one distance.And a fixed electrode, it is arranged on the sidewall of substrate cavity and neighbouring described movable electrode.Institute State that movable electrode and described fixed electrode be static at balance ring or has certain area coverage in rotation process.Described 6th Electric capacity includes a movable electrode, is arranged on the second surface of balance ring, is positioned at the first limit of the second axle, and away from the second axle One distance.And a fixed electrode, on the sidewall of the cavity being arranged at substrate and neighbouring described movable electrode, described can Moving electrode and described fixed electrode be static at balance ring or has certain area coverage in rotation process.

According to another feature of the present utility model, described 3rd sensing circuit has a first input end, and one second is defeated Enter end and an outfan.First input end and the second input are coupled respectively to fixed electrode and the 6th electric capacity of the 5th electric capacity Fixed electrode.Described sensing circuit is set as producing one the 3rd of the capacitance corresponding to described 3rd series capacitance group Magnitude of voltage exports to outfan.

According to another feature of the present utility model, described capacitance sensor also includes one first differential amplifier circuit.Institute State the first differential amplifier circuit and there is a first input end and one second input.First input end is coupled in the second sensing electricity The outfan on road, the second input is coupled in the outfan of the 3rd sensing circuit.Described first differential amplifier circuit is set as Exporting a magnitude of voltage, described magnitude of voltage corresponds to described second magnitude of voltage and described third voltage value.

According to another feature of the present utility model, the scanning board of described capacitive sensing apparatus is first axial second One the 5th electric capacity and one the 6th electric capacity, one the 3rd electric conductor and one the 3rd sensing circuit it is additionally provided with on limit and the first limit.Institute State the 5th electric capacity and include a movable electrode, be arranged on the first surface of scanning board, be positioned at the second limit of the first axle, and away from First axle one distance.And a fixed electrode, it is arranged on the sidewall of substrate cavity and neighbouring described movable electrode.Institute State movable electrode and described fixed electrode is static at scanning board or has certain area coverage in rotation process.Described 6th Electric capacity includes a movable electrode, is arranged on the second surface of scanning board, is positioned at the first limit of the first axle, and away from the first axle One distance.And a fixed electrode, on the sidewall of the cavity being arranged at substrate and neighbouring described movable electrode.Described can Moving electrode and described fixed electrode be static at scanning board or has certain area coverage in rotation process.

According to another feature of the present utility model, described 3rd sensing circuit has a first input end, and one second is defeated Enter end and an outfan.First input end and the second input are coupled respectively to fixed electrode and the 6th electric capacity of the 5th electric capacity Fixed electrode.Described sensing circuit is set as producing one the 3rd of the capacitance corresponding to described 3rd series capacitance group Magnitude of voltage exports to described outfan.

According to another feature of the present utility model, described capacitive sensing apparatus also includes one second differential amplifier circuit. Described second differential amplifier circuit has a first input end and one second input.First input end is coupled in the first sensing The described outfan of circuit.Second input is coupled in the described outfan of the 3rd sensing circuit.Described differential amplifier circuit Being set as exporting a magnitude of voltage, described magnitude of voltage corresponds to described first magnitude of voltage and described third voltage value.

Accompanying drawing explanation

Fig. 1 is the top view describing the micro scanner according to this utility model one embodiment；

Fig. 2 show schematically show the field magnet in the micro scanner shown in Fig. 1 and is loaded on a magnetic of one scan plate Relation between body；

Fig. 3 is the profile along micro scanner line B-B shown in Fig. 1, describes according to this utility model one embodiment Electric capacity structure is set；

Fig. 4 is the sensing circuit fundamental block diagram describing the capacitive sensing apparatus according to this utility model one embodiment；

Fig. 5 is to describe another sensing circuit fundamental block diagram according to a capacitive sensing apparatus of the present utility model；

Fig. 6 is the basic circuit diagram describing the differential amplifier circuit according to this utility model one embodiment；

Fig. 7 is the profile along line A-A of the micro scanner shown in Fig. 1, describes according to this utility model one embodiment Electric capacity arranges structure；

Fig. 8 is the another sensing circuit basic subrack describing the capacitive sensing apparatus according to this utility model one embodiment Figure；

Fig. 9 is the fundamental block diagram of the other sensing circuit describing a capacitive sensing apparatus of the present utility model；

Figure 10 is the basic circuit diagram describing another differential amplifier circuit according to this utility model one embodiment；

Figure 11 is described as the top view of the micro scanner according to another embodiment of this utility model；

Figure 12 is the profile along line A-A of the micro scanner shown in Figure 11, describes according to another reality of this utility model The electric capacity executing example arranges structure；And

Figure 13 is the profile along line B-B of the micro scanner shown in Figure 11, describes according to another reality of this utility model The electric capacity executing example arranges structure.

Detailed description of the invention

Here, referring to the drawings different embodiments of the present utility model are described below, in the accompanying drawings, with identical attached Figure labelling represents analog structure in each figure or has the element of similar functions.It should be noted that accompanying drawing is intended to be easy to explain State preferred embodiment of the present utility model.They are not intended as carrying out this utility model detailed description, or new to this practicality The scope of type has limited.It addition, accompanying drawing does not necessarily means that actual size and proportionate relationship.Furthermore, it is to be understood that It is that the word such as such as top, bottom, up, down, left, right, before and after, vertical, level is in order to the most just In describing different element of the present utility model.They are not intended as the direction to different elements of the present utility model or each element Between spatial relationship limited.

This utility model provides an a kind of floating scanning board for sensing in micro scanner or a floating equilibrium ring A capacitive sensing apparatus of angular displacement, judge the concordance between image and the incoming video signal being projected with this, Thus effectively the projected light beam scanned and project is adjusted effectively, and then guarantee the accuracy of projected light beam. The output signal of capacitive sensing apparatus can be supplied to a feedback circuit of the projection arrangement comprising this micro scanner.According to this Utility model, has a micro scanner of a capacitive sensing apparatus and is capable of altofrequency, high-resolution, the sweeping of wide-angle Retouch, and this capacitive sensing apparatus can be that the normal and stable operation of micro scanner provides a feedback mechanism.

Fig. 1 is the top view schematically describing the micro scanner 100 comprising one scan plate 40.Citing and Speech, micro scanner 100 is made on semiconductor wafer by semiconductor fabrication process.Such as, this semiconductor wafer can To be silicon (SOI, the Silicon on Insulator) wafer in bulk silicon (Bulk Silicon) wafer or dielectric substrate.Figure 1 part that illustrate only the semiconductor wafer as semiconductor substrate 10.One cavity 20 is formed at substrate 10 In one top main surfaces 11.According to an embodiment, cavity 20 is in a through hole of substrate 10, and this through hole has one Sidewall 30.According to another embodiment, cavity 20 is in a female or a groove of substrate 10, this female Or groove have a sidewall 30 and be connected with sidewall 30 one bottom (not shown in accompanying drawing).

Fig. 2 show schematically show the field magnet 42 in the micro scanner 100 shown in Fig. 1 and is loaded on scanning board Relation between one magnet 36 of 40.In a manufacture process of micro scanner 100, sweeping in micro scanner 100 Retouch plate 40 by one or more thin thin rod members (not shown in accompanying drawing) and substrate 10 physical connection.Physical connection will Scanning board 40 is maintained in cavity 20.Being assembled after substrate 10 at field magnet 42, it produces in cavity 20 Magnetic field 41, and magnet 36 is suspended in magnetic field 41.Scanning board 40 in micro scanner 100 can be located on or near flat Weighing apparatus is suspended in cavity 20 at position 45.At this point it is possible to disconnect in micro scanner 100 with very brief and fierce air-flow Scanning board 40 and substrate 10 between physical connection, and in cavity 20, eliminate the residual substance that disconnects.

Fig. 3 is to schematically show the micro scanner 100 with capacitive sensing apparatus as shown in Figure 1 along line B-B Sectional view.As shown in figures 1 and 3, one scan plate 40 is positioned at cavity 20, and is surrounded by sidewall 30.Scanning Plate 40 has an end face 401 and the bottom surface 402 relative to end face 401.One reflecting mirror 50 is arranged at scanning board 40 On end face 401.According to this utility model one preferred embodiment, reflecting mirror 50 includes the end face being deposited on scanning board 40 The one platinum reflecting surface of 401.One Guan Bi circuit coil 60 is arranged at the end face 401 of scanning board 40.New according to this practicality One preferred embodiment of type, Guan Bi circuit coil 60 for have a conductive material (such as, golden, copper, aluminum or previous materials Combination in any) one Guan Bi circuit winding.It is apparent that according to the technical solution of the utility model, close circuit coil 60 The bottom surface 402 of scanning board 40 can also be arranged on.

As shown in Figure 1 to Figure 3, magnet 36 can include a toroidal magnet the most conformal with scanning board 40.This Outward, magnet 36 preferably produces a magnetic field 37 substantially vertical with the bottom surface 402 of scanning board 40 in magnet 36.Micro- Scanning device 100 also includes one or more field magnet 42 being adjacent to substrate 10.Field magnet 42 can be arranged on substrate On 10, under and/or around.Field magnet 42 produces the magnetic field 41 round scanning board 40 in cavity 20.Magnetic Field 41 has a vertical component of the end face 401 (or bottom surface 402) being perpendicular to scanning board 40 and is parallel to scanning board 40 A horizontal component of end face 401 (or bottom surface 402).

According to this utility model, the vertical component in magnetic field 41 is heterogeneous in the cavity 20 of substrate 10.According to One embodiment, the direction of the vertical component in magnetic field 41 heterogeneous is identical with direction in magnet 36, the magnetic field 37, and A maximum intensity is reached at a position 45 in cavity 20.According to another embodiment, hanging down of magnetic field 41 heterogeneous In opposite direction in magnet 36 of the direction of straight component and magnetic field 37, and reach one at the position 45 in cavity 15 Minimum strength.At position 45, the vertical component in magnetic field 41 applies one zero magnetic to magnet 36 and makes a concerted effort.Sweep when being arranged at When retouching magnet 36 deviation position 45 of plate 40, the vertical component in magnetic field 41 heterogeneous towards direction, position 45 to magnet 36 apply one makes a concerted effort, thus promotes magnet 36 to be back to position 45.Therefore, in scanning board 40 is positioned at cavity 20 During position 45, it is in a stable poised state.

Here, the setting of the magnet 36 shown in Fig. 2 and field magnet 42 is merely to specifically explain by an embodiment The scanning board 40 stating micro scanner 100 is suspended in the principle in cavity 20.But, the magnet 36 shown in Fig. 2 and field The setting of magnet 42 is not so that unique embodiment that the scanning board 40 of micro scanner 100 is suspended in cavity 20. It is apparent that respectively field magnet and/or the magnetic north pole of magnet and south magnetic pole are used and the field magnet 42 shown in Fig. 2 and magnet The magnetic north pole of 36 and south magnetic pole are reversed the suspension also being able to realize scanning board 40 in cavity 20.Particular content can To submit to March 31 in 2016 refering to applicant, Application No. 201610195818.2, entitled " have floating The micro scanner of balance ring, and comprise the laser projection device of this micro scanner " and application number 201610195832.2, Two practicalities of entitled " have the micro scanner of floating scanning board and comprise the laser projection device of this micro scanner " are new Type patent application.

Guan Bi circuit coil 60 as shown in Figure 3 includes a Guan Bi circuit coil with multiturn.Based on this practicality Novel technical scheme, coil 60 can include a Guan Bi circuit coil or some Guan Bi circuit coils, and each coil has There are a circle or the multiturn number of turns.In coil 60 includes the embodiment of more than one Guan Bi circuit coil, different coils The different parts of scanning board 40 can be arranged on.

When micro scanner 100 does not works or is not in scan operation, it is preferable that the end face 401 of scanning board 40 is flat Row is in a first type surface 11 of substrate 10.In one scan operates, scanning board 40 is set as responding a driving signal with around one First axle rotates and rotates around one second axle vertical with the first axle, and scanning board 40 is relative to the first type surface 11 of substrate 10 Direction change over time.Such change embodies scanning board 40 and leaves the angular displacement of its equilbrium position.Sensing The angular displacement of scanning board 40 just can provide the relevant information of the location of pixels in projecting video images.

As it is shown on figure 3, according to an embodiment of the present utility model, a capacitive sensing apparatus 300 includes along along Fig. 1 Shown in line B-B diagonal arrange an electric capacity C11 and an electric capacity C21.Wherein, electric capacity C11 includes that one can galvanic electricity Pole 411 and a fixed electrode 111.Movable electrode 411 is arranged on the end face 401 of scanning board 40, is positioned at the first axle First limit (left one side of something of scanning board 40 shown in Fig. 3) of (axle i.e. overlapped with line A-A), and distance first Axle one distance.On the sidewall 30 of the cavity 20 that fixed electrode 111 is arranged at substrate 10, and be adjacent to can galvanic electricity Pole 411.Movable electrode 411 and fixed electrode 111 static at scanning board 40 or rotate during there is certain covering Area.In the same manner, electric capacity C21 includes movable electrode 421 and a fixed electrode 122.Movable electrode 421 is arranged at On the bottom surface 402 of scanning board 40, it is positioned at one second limit (Fig. 3 shown in scanning board 40 relative with the first limit of the first axle Right one side of something), and distance the first axle one distance.Fixed electrode 122 is arranged at the sidewall of the cavity 20 of substrate 10 On 30, and it is adjacent to movable electrode 421.Movable electrode 421 and fixed electrode 122 are static at scanning board 40 or rotate During there is certain area coverage.In other embodiments, electric capacity C11 and/or electric capacity C21 can not be along B- B line is arranged, say, that electric capacity C11 and/or electric capacity C21 can deviate line B-B and arrange.Such as, electric capacity C11 Can be arranged on below line B-B as shown in Figure 1 and the region (but not on line A-A) on the line A-A left side, electric capacity C21 then can be arranged on the region (but not on line A-A) above line B-B as shown in Figure 1 and on the right of line A-A. Certainly, two electric capacity arranged along line B-B diagonal make the accurate journey of the sensing scanning board angular displacement of capacitive sensing apparatus Du Genggao.According to this utility model, the fixed electrode 111 of electric capacity C11 both can be arranged on the master meter of adjacent substrate 10 On the sidewall 30 in face 11 (as shown in Figure 3), it is also possible to be arranged on the plane of flattening of first type surface 11 of substrate 10, i.e. The horizontal plane of the fixed electrode 111 of electric capacity C11 flushes with the first type surface 11 of substrate 10.

Capacitive sensing apparatus also includes movable electrode 411 and the movable electrode of electric capacity C21 being coupled in electric capacity C11 One electric conductor (not shown in accompanying drawing) of 421, makes, with this, one first series connection that electric capacity C11 and electric capacity C21 constituted Capacitance group C₀1.Here, electric conductor can be the wire or a conductive adhesive tape being embedded in scanning board 40.This area Electric conductor can be selected according to practical situations such as the size of scanning board or materials and set by technical staff.

With continued reference to Fig. 1 and Fig. 3, capacitive sensing apparatus also includes electric capacity C31 and electric capacity C41, and both are also along B- B line diagonal is arranged.Wherein, electric capacity C31 includes movable electrode 431 and a fixed electrode 121, a movable electrode 431 It is arranged on the end face 401 of scanning board 40, is positioned at second limit (right one side of something of scanning board 40 shown in Fig. 3) of the first axle, And distance the first axle one distance.On the sidewall 30 of the cavity 20 that fixed electrode 121 is arranged at substrate 10, and It is adjacent to movable electrode 431.Movable electrode 431 and fixed electrode 121 static at scanning board 40 or rotate during There is certain area coverage.Similarly, electric capacity C41 includes movable electrode 441 and a fixed electrode 112, movably Electrode 441 is arranged on the bottom surface 402 of scanning board 40, be positioned at the first axle the first limit (scanning board 40 shown in Fig. 3 Left one side of something), and distance the first axle one distance.Fixed electrode 112 is arranged at the sidewall 30 of the cavity 20 of substrate 10 On, and it is adjacent to movable electrode 441.Movable electrode 441 and fixed electrode 112 static at scanning board 40 or rotate mistake Journey has certain area coverage.In other embodiments, electric capacity C31 and/or electric capacity C41 can not be along line B-B Arrange, say, that electric capacity C31 and/or electric capacity C41 can also deviate line B-B and arrange.Certainly, along line B-B pair Linea angulata arrange two electric capacity make capacitive sensing apparatus sensing scanning board angular displacement accuracy higher.According to this practicality Novel, the fixed electrode 121 of electric capacity C31 can be arranged on the sidewall of the first type surface 11 of adjacent substrate 10 as shown in Figure 3 On 30, it is also possible to be arranged on the first type surface 11 of substrate 10, i.e. the horizontal plane of the fixed electrode 121 of electric capacity C31 with The first type surface 11 of substrate 10 flushes.

Capacitive sensing apparatus also includes movable electrode 431 and the movable electrode of electric capacity C41 being coupled in electric capacity C31 Another electric conductor (not shown in accompanying drawing) of 441, makes, with this, one second string that electric capacity C31 and electric capacity C41 constituted Connection capacitance group C₀2.Here, electric conductor can be the wire or a conductive adhesive tape being embedded in scanning board 40.This area Technical staff according to practical situations such as the size of scanning board or materials electric conductor can be selected and set.

Fig. 4 schematically describes a sensing electricity of the capacitive sensing apparatus 300 according to this utility model one embodiment Road 310.As shown in Figure 3 and Figure 4, according to an embodiment of the present utility model, capacitive sensing apparatus 300 includes one One sensing circuit 310, it has a first input end 311, one second input 313, and an outfan, the first input End 311 and the second input 313 are coupled respectively to fixed electrode 111 and the fixed electrode of electric capacity C21 of electric capacity C11 122, thus the first series capacitance group C being made up of electric capacity C11 and electric capacity C21₀1 is coupled in an inductance L1, constitutes One oscillating circuit.Oscillating circuit is coupled in an agitator 315 and constitutes a resonance circuit.Resonance circuit generation one has specific The current signal of frequency.One limiting amplifier 317 is coupled in the outfan of this resonance circuit, and believes its electric current exported Number carry out fixed ampllitude amplification, it is ensured that output has the current signal of characteristic frequency.One descriminator 319 is coupled in limiting amplifier The outfan of 317, and the current signal exported according to it determines a frequency signal, and this frequency signal is converted to One magnitude of voltage V1 also exports.

Fig. 5 schematically describes another sensing of the capacitive sensing apparatus 300 according to this utility model one embodiment Circuit 510.As shown in Figure 3 and Figure 5, according to an embodiment of the present utility model, capacitive sensing apparatus 300 also includes One second sensing circuit 510, it has a first input end 511, one second input 513 and an outfan, and first Input 511 and the second input 513 are coupled respectively to the fixed electrode 121 of electric capacity C31 and the fixing of electric capacity C41 Electrode 112.The second series capacitance group C being made up of electric capacity C31 and electric capacity C41₀2 are coupled in an inductance L2, constitute One oscillating circuit.Oscillating circuit is coupled in an agitator 515 and constitutes a resonance circuit.Resonance circuit generation one has specific The current signal of frequency.One limiting amplifier 517 is coupled in the outfan of this resonance circuit, and believes its electric current exported Number carry out fixed ampllitude amplification, it is ensured that output has the current signal of characteristic frequency.One descriminator 519 is coupled in limiting amplifier The outfan of 517, and the current signal exported according to it determines a frequency signal, and this frequency signal is converted to Two magnitude of voltage V2 also export.

Electric capacity C11, C21, C31, C41 are used for sensing scanning board 40 around the first axle along line A-A shown in Fig. 1 Rotation.It addition, with the first series capacitance group C being made up of electric capacity C11 and electric capacity C21₀First sensing of 1 coupling Circuit 310 is set as producing corresponding to the first series capacitance group C₀First magnitude of voltage V1 of one capacitance of 1, and by electricity Hold the second series capacitance group C that C31 and electric capacity C41 is constituted₀It is right that second sensing circuits 510 of 2 couplings are set as producing Should be in the second series capacitance group C₀Second magnitude of voltage V2 of one capacitance of 2.In the first axle rotation process, electric capacity Area coverage between movable electrode and the fixed electrode of C11, C21, C31, C41 can change, and this change The first series capacitance group C being made up of electric capacity C11 and electric capacity C21 will be made₀1 and by electric capacity C31 and electric capacity C41 The second series capacitance group C constituted₀The capacitance of 2 changes, so that the first of the first sensing circuit 310 output Second magnitude of voltage V2 of magnitude of voltage V1 and the output of the second sensing circuit 510 also produces corresponding change.Electric capacity C11, Between movable electrode and the fixed electrode of C21, C31, C41, the size of area coverage indicates scanning board 40 relative to base The first type surface 11 at the end 10 is around the angular displacement of the first axle of line A-A.

Fig. 6 is the basic circuit diagram of a differential amplifier circuit 410 of this utility model embodiment.New according to this practicality The embodiment of type, the first sensing circuit 310 exports the first magnitude of voltage V1, and the second sensing circuit 510 exports the second voltage Value V2.Capacitive sensing apparatus 300 also includes a differential amplifier circuit 410, effectively to amplify differential input signal, and fall The impact of low interference signal is to improve sensing precision and reliability.First series capacitance group C₀1 corresponding first magnitude of voltage V1, Second series capacitance group C₀Second magnitude of voltage V2 of 2 correspondences.Differential amplifier circuit 410 has a first input end 421 And one second input 422.First magnitude of voltage V1 and the second magnitude of voltage V2 is coupled respectively to differential amplifier circuit 410 First input end 421 and the second input 422.In this utility model embodiment, two input terminal voltage values V1 and V2, Set and be coupled to differential amplifier circuit 410 with difference mode signal.Under difference mode signal coupled modes, the first magnitude of voltage V1 and The phase place of the wherein road voltage signal in the second magnitude of voltage V2 and the phase place contrast of another road voltage signal.Based on The technical solution of the utility model, when initial setting up electric capacity, can be to the first series connection corresponding to the first magnitude of voltage V1 Capacitance group C₀1 and second the second series capacitance group C corresponding to magnitude of voltage V2₀2 are adjusted, so that the first string Connection capacitance group C₀First magnitude of voltage V1 of 1 corresponding output and the second series capacitance group C₀Second magnitude of voltage of 2 corresponding outputs V2 amplitude of variation is roughly equal, and phase place is substantially opposite.Such as, adjust electric capacity C11, movable in C21, C31, C41 Area coverage and distance between electrode and fixed electrode.Difference between first magnitude of voltage V1 and the second magnitude of voltage V2 is i.e. Effective input signal for differential amplifier circuit 410.This effective input signal is through circuit impedance R1, R2, R3, R4 After the amplification of operational amplifier A, export a magnitude of voltage V₀1.Magnitude of voltage V₀1 corresponding to the first magnitude of voltage V1 and the The difference of two magnitude of voltage V2, and be the amplified numerical value of the two voltage input signal difference.

It addition, micro scanner 100 includes an image-signal processor, it has a signal synchronization module (in figure not Illustrate).The voltage signal of the output of capacitive sensing apparatus 300 feeds back to synchronization module.At the rotation process around the first axle In.Signal processor is adjusted the position, angle of scanning board 40 according to feedback signal, thus ensures that micro scanner 100 is The accuracy in the projected light beam direction scanned and project in one axle rotation process.

According to the technical solution of the utility model, electric capacity C11, C21 as shown in Figure 3 or electric capacity C31 is only set, C41 also can sense the scanning board 40 angular displacement around the first axle along line A-A shown in Fig. 1.There is electric capacity C11 simultaneously, The sensing accuracy sensing accuracy of the capacitive sensing apparatus 300 of C21 and electric capacity C31, C41 will be typically higher than in only having There are electric capacity C11, C21 or electric capacity C31, the 300 of the capacitive sensing apparatus of C41.But, due to micro scanner 100 Volume is the least, arranges the most electric capacity the most therein, and manufacture difficulty is the biggest, and production cost also can be significantly increased. In consideration of it, those skilled in the art should comprehensively sensing accuracy, manufacture complexity and Productive statistics etc. many-sided because of Element, arranges the electric capacity of respective numbers in capacitive sensing apparatus.

Fig. 7 is the sectional view schematically showing micro scanner 100 along line A-A as shown in Figure 1.According to this practicality A novel embodiment, capacitive sensing apparatus 300 includes electric capacity C32 and the electric capacity C42 arranged along line A-A diagonal. Wherein, electric capacity C32 includes movable electrode 432 and a fixed electrode 131.Movable electrode 432 is arranged at scanning board 40 End face 401 on, be positioned at (scanning board 40 shown in Fig. 7, the first limit of one second axle (axle i.e. overlapped) with line B-B Left one side of something), and distance the second axle one distance.Fixed electrode 131 is arranged at the sidewall of the cavity 20 of substrate 10 On 30, and it is adjacent to movable electrode 432.Movable electrode 432 and fixed electrode 131 are static at scanning board 40 or turn There is during Dong certain area coverage.In the same manner, electric capacity C42 includes movable electrode 442 and a fixed electrode 142, movable electrode 442 is arranged on the bottom surface 402 of scanning board 40, and the second limit being positioned at the second axle (is swept shown in Fig. 7 Retouch right one side of something of plate 40), and distance the second axle one distance.Fixed electrode 142 is arranged at the cavity 20 of substrate 10 Sidewall 30 on, and be adjacent to movable electrode 442.Movable electrode 442 and fixed electrode 142 are static at scanning board 40 Or during rotating, there is certain area coverage.In other embodiments, electric capacity C32 and/or electric capacity C42 is permissible Do not arrange along line A-A, say, that electric capacity C32 and/or electric capacity C42 can deviate line A-A and arrange.Such as, electricity Hold C32 and can be arranged on below line A-A as shown in Figure 1 and the region (but not on line B-B) on the line B-B left side, Electric capacity C42 then can be arranged on region above line A-A as shown in Figure 1 and on the right of line B-B (but not at line B-B On).Certainly, two electric capacity arranged along line A-A diagonal make the sensing scanning board angular displacement of capacitive sensing apparatus Accuracy is more preferable.According to this utility model, the fixed electrode 131 of electric capacity C32 both can be arranged on adjacent substrate 10 On the sidewall 30 of first type surface 11 (as shown in Figure 7), it is also possible to be arranged on the plane of flattening of the first type surface 11 of substrate 10 On, i.e. the horizontal plane of the fixed electrode 131 of electric capacity C32 flushes with the first type surface 11 of substrate 10.

What capacitive sensing apparatus 300 also included the movable electrode 432 being coupled in electric capacity C32 and electric capacity C42 can galvanic electricity One electric conductor (not shown in accompanying drawing) of pole 442, make that electric capacity C32 and electric capacity C42 constituted with this one the 3rd Series capacitance group C₀3.Here, electric conductor can be the wire or a conductive adhesive tape being embedded in scanning board 40.Ability Electric conductor can be selected according to practical situations such as the size of scanning board or materials and set by the technical staff in territory.

With continued reference to Fig. 1 and Fig. 7, capacitive sensing apparatus 300 also includes electric capacity C51 and electric capacity C61, Liang Zheye Arrange along line A-A diagonal.Wherein, electric capacity C51 includes movable electrode 451 and a fixed electrode 141, can galvanic electricity Pole 451 is arranged on the end face 401 of scanning board 40, is positioned at (the right side of scanning board 40 shown in Fig. 7, the second limit of the second axle Half of), and distance the second axle one distance.Fixed electrode 141 is arranged at the sidewall 30 of the cavity 20 of substrate 10 On, and it is adjacent to movable electrode 451.Movable electrode 451 and fixed electrode 141 are static at scanning board 40 or rotation During there is certain area coverage.Similarly, electric capacity C61 includes movable electrode 461 and a fixed electrode 132, Movable electrode 461 is arranged on the bottom surface 402 of scanning board 40, is positioned at the first limit (scanning board shown in Fig. 7 of the second axle Left one side of something of 40), and distance the second axle one distance.Fixed electrode 132 is arranged at the side of the cavity 20 of substrate 10 On wall 30, and it is adjacent to movable electrode 461.Movable electrode 461 and fixed electrode 132 are static at scanning board 40 or turn There is during Dong certain area coverage.In other embodiments, electric capacity C51 and/or electric capacity C61 can not edge Line A-A is arranged, say, that electric capacity C51 and/or electric capacity C61 can deviate line A-A and arrange.Certainly, along A-A Line diagonal arrange two electric capacity make capacitive sensing apparatus sensing scanning board angular displacement accuracy higher.According to this Utility model, the fixed electrode 141 of electric capacity C51 both can be arranged on the sidewall 30 of the first type surface 11 of adjacent substrate 10 Upper (as shown in Figure 7), it is also possible to be arranged on the plane of flattening of first type surface 11 of substrate 10, i.e. electric capacity C51's is fixing The horizontal plane of electrode 141 flushes with the first type surface 11 of substrate 10.

What capacitive sensing apparatus 300 also included the movable electrode 451 being coupled in electric capacity C51 and electric capacity C61 can galvanic electricity Another electric conductor (not shown in accompanying drawing) of pole 461, make that electric capacity C51 and electric capacity C61 constituted with this one Four series capacitance groups C₀4.Here, electric conductor can be the wire or a conductive adhesive tape being embedded in scanning board 40.This Electric conductor can be selected according to practical situations such as the size of scanning board or materials and set by the technical staff in field.

Fig. 8 schematically describes the another sensing of the capacitive sensing apparatus 300 according to this utility model one embodiment Circuit 710.As shown in Figure 7 and Figure 8, according to an embodiment of the present utility model, capacitive sensing apparatus 300 includes sense Slowdown monitoring circuit 710, it has a first input end 711, one second input 713 and an outfan, first input end 711 Fixed electrode 131 and the fixed electrode 142 of electric capacity C42 of electric capacity C32 it is coupled respectively to the second input 713.By Electric capacity C32 and electric capacity C42 constitutes the 3rd series capacitance group C₀3 are coupled in an inductance L3, constitute an oscillating circuit.Shake Swing circuit to be coupled in an agitator 715 and constitute a resonance circuit.Resonance circuit produces a current signal with characteristic frequency. One limiting amplifier 717 is coupled in the outfan of this resonance circuit, and its current signal exported is carried out fixed ampllitude amplification, Guarantee to export the current signal with characteristic frequency.One descriminator 719 is coupled in the outfan of limiting amplifier 717, and Determine a frequency signal according to its current signal exported, and this frequency signal is converted to third voltage value V3 defeated Go out.

Fig. 9 schematically describes an other sensing electricity of a capacitive sensing apparatus 300 of this utility model one embodiment Road 910.As shown in figures 7 and 9, according to an embodiment of the present utility model, capacitive sensing apparatus 300 includes sensing Circuit 910, it has a first input end 911, one second input 913 and an outfan, first input end 911 Fixed electrode 141 and the fixed electrode 132 of electric capacity C61 of electric capacity C51 it is coupled respectively to the second input 913.

The 3rd series capacitance group C is constituted by electric capacity C51 and electric capacity C61₀4 are coupled in an inductance L4, constitute an oscillating circuit. Oscillating circuit is coupled in an agitator 915 and constitutes a resonance circuit.Resonance circuit produces an electric current with characteristic frequency Signal.One limiting amplifier 917 is coupled in the outfan of this resonance circuit, and carries out its current signal exported surely Width amplifies, it is ensured that output has the current signal of characteristic frequency.One descriminator 919 is coupled in limiting amplifier 917 Outfan, and the current signal exported according to it determines a frequency signal, and this frequency signal is converted to the 4th electricity Pressure value V4 also exports.

Electric capacity C32, C42, C51, C61 are used for sensing scanning board 40 around the second axle along line B-B shown in Fig. 1 Rotation.It addition, with the 3rd series capacitance group C being made up of electric capacity C32 and electric capacity C42₀3rd sensing of 3 couplings Circuit 710 is set as producing corresponding to the 3rd series capacitance group C₀Third voltage value V3 of one capacitance of 3, and by electricity Hold the 4th series capacitance group C that C51 and electric capacity C61 is constituted₀It is right that 4th sensing circuits 910 of 4 couplings are set as producing Ying Yu tetra-series capacitance group C₀4th magnitude of voltage V4 of one capacitance of 4.In the second axle rotation process, electric capacity Area coverage between movable electrode and the fixed electrode of C32, C42, C51, C61 can change, and this change The 3rd series capacitance group C being made up of electric capacity C32 and electric capacity C42 will be made₀3 and by electric capacity C51 and electric capacity C61 The 4th series capacitance group C constituted₀The capacitance of 4 changes, so that the 3rd of the 3rd sensing circuit 710 output the 4th magnitude of voltage V4 of magnitude of voltage V3 and the output of the 4th sensing circuit 910 also produces corresponding change.Electric capacity C32, Between movable electrode and the fixed electrode of C42, C51, C61, the size of area coverage indicates scanning board 40 relative to base The first type surface 11 at the end 10 is around the angular displacement of the second axle.

Figure 10 schematically describes another differential amplifier circuit 810 according to this utility model one embodiment.According to Embodiment of the present utility model, the 3rd sensing circuit 710 exports third voltage value V3, and the 4th sensing circuit 910 exports 4th magnitude of voltage V4.Capacitive sensing apparatus 300 also includes differential amplifier circuit 810, effectively to amplify difference-mode input Signal, reduces the impact of interference signal.3rd series capacitance group C₀3 corresponding third voltage value V3, the 4th series capacitance Group C₀Second magnitude of voltage V4 of 4 correspondences.Differential amplifier circuit 810 has first input end 821 and one second input End 822.Third voltage value V3 and the 4th magnitude of voltage V4 are coupled respectively to the first input end of differential amplifier circuit 810 821 and second input 822.In this utility model embodiment, two input terminal voltage values V3 and V4, set with difference Mould signal is coupled to differential amplifier circuit 810.Under difference mode signal coupled modes, third voltage value V3 and the 4th voltage The phase place of the wherein road voltage signal in value V4 and the opposite in phase of another road voltage signal.Based on of the present utility model Technical scheme, when initial setting up electric capacity, can be to the 3rd series capacitance group C corresponding to third voltage value V3₀3 with And the 4th series capacitance group C that the 4th corresponding to magnitude of voltage V4₀4 are adjusted, so that the 3rd series capacitance group C₀3 Third voltage value V3 of corresponding output and the 4th series capacitance group C₀4th magnitude of voltage V4 of 4 corresponding outputs are close or phase With.Such as, adjustment electric capacity C32, area coverage between movable electrode and the fixed electrode of C42, C51, C61, or Person adjusts electric capacity C32, the distance between movable electrode and the fixed electrode of C42, C51, C61.Third voltage value V3 And the 4th the difference between magnitude of voltage V4 be effective input signal of differential amplifier circuit 810.This effective input signal Through circuit impedance R5, R6, R7, R8 and operational amplifier A ' amplification after, export a magnitude of voltage V₀2.Electricity Pressure value V₀2 correspond to third voltage value V3 and the difference of the 4th magnitude of voltage V4, and are the two voltage input signals The numerical value that difference is amplified.

According to the technical solution of the utility model, electric capacity C32, C42 as shown in Figure 7 or electric capacity C51 is only set, C61 also can sense the scanning board 40 angular displacement around the second axle along line B-B shown in Fig. 1.Certainly, only there is electric capacity C32, C42 or electric capacity C51, the sensing accuracy of the capacitive sensing apparatus of C61 is less than certainly has electric capacity C32 simultaneously, C42 and electric capacity C51, the sensing accuracy of the capacitive sensing apparatus of C61.According to an embodiment of the present utility model, Capacitive sensing apparatus can only arrange the first series capacitance group C₀1 (i.e. electric capacity C11, C21) or the second series capacitance group C₀2 (C31, C41) to sense the scanning board 40 angular displacement around the first axle along line A-A shown in Fig. 1, and only Three series capacitance groups C₀3 (i.e. electric capacity C32, C42) or the 4th series capacitance groups C₀4 (i.e. electric capacity C51, C61) with Sensing scanning board 40 is around the angular displacement of the second axle along line B-B shown in Fig. 1.According to another embodiment of the present utility model, First series capacitance group C can be only set in capacitive sensing apparatus₀1 (i.e. electric capacity C11, C21) or the second series capacitance Group C₀2 (i.e. electric capacity C31, C41) to sense the scanning board 40 angular displacement around the first axle along line A-A shown in Fig. 1, And simultaneously the 3rd series capacitance group C₀3 (i.e. electric capacity C32, C42) and the 4th series capacitance groups C₀4 (i.e. electric capacity C51, C61) to sense the scanning board 40 angular displacement around the second axle along line B-B shown in Fig. 1.According to of the present utility model again One embodiment, can arrange the first series capacitance group C in capacitive sensing apparatus simultaneously₀1 (i.e. electric capacity C11, C21) and Second series capacitance group C₀2 (i.e. electric capacity C31, C41) are to sense scanning board 40 around along first of line A-A shown in Fig. 1 The angular displacement of axle, and the only the 3rd series capacitance group C₀3 (i.e. electric capacity C32, C42) or the 4th series capacitance groups C₀4 (i.e. Electric capacity C51, C61) to sense the scanning board 40 angular displacement around the second axle along line B-B shown in Fig. 1.According to this practicality A novel preferred embodiment, can arrange the first series capacitance group C in capacitive sensing apparatus simultaneously₀1 (i.e. electric capacity C11, C21) and the second series capacitance group C₀2 (i.e. electric capacity C31, C41) are to sense scanning board 40 around along A-A shown in Fig. 1 The angular displacement of the first axle of line, and the 3rd series capacitance group C simultaneously₀3 (i.e. electric capacity C32, C42) and the 4th series capacitances Group C₀4 (i.e. electric capacity C51, C61) are to sense the scanning board 40 angular displacement around the second axle along line B-B shown in Fig. 1. Based on this, those skilled in the art can comprehensively sensing accuracy, manufacture the many factors such as complexity and cost input, Electric capacity quantity in capacitive sensing apparatus is selected accordingly and arranges.

Figure 11 schematically describes the structure of the micro scanner 200 according to another embodiment of this utility model.Figure 12 and Figure 13 is the micro scanner shown in Figure 11 along line A-A with along the profile of line B-B respectively.Due to Figure 11 institute The structure of the micro scanner 200 shown is similar to the structure of the micro scanner 100 shown in Fig. 1, topmost difference It is: the micro scanner 200 shown in Figure 11 also includes a balance ring 70.Here, at the micro scanner 200 of Figure 11 In mark with identical reference with the same or similar parts in the micro scanner 100 of Fig. 1.Come by embodiment Illustrating, micro scanner 200 is formed on semiconductor wafer by semiconductor fabrication process and makes.Such as, this wafer Can be silicon body (Bulk Silicon) wafer or silicon (SOI) wafer at the insulation end.Figure 11 to Figure 13 shows work A part for the semiconductor wafer of semiconductor substrate 10.One cavity 20 is formed at a top main surfaces of substrate 10 In 11.According to an embodiment, cavity 20 is in a through hole of substrate 10, and this through hole has as shown in figure 12 Sidewall 30.Capacitive sensing apparatus in the micro scanner 200 of the present embodiment also includes balancing ring 70.70, ring of balance In the cavity 20 of substrate 10 and surround scanning board 40.Balance ring 70 is by toggle 26,28 with scanning board 40 even Connect.Scanning board 40 is set as around being parallel to toggle 26, one first axle (axle i.e. overlapped with line A-A) of 28 Rotating, balance ring 70 is set as rotating around one second axle (axle i.e. overlapped with line B-B) being perpendicular to the first axle.

Toggle 26,28 shown in Figure 11 is straight and has the thickness identical with scanning board 40 and balance ring 24. It should be understood that this is not intended to limit scope of the present utility model.According to different embodiments of the present utility model, torsion Arm 26,28 can have such as bending or the difformity such as snakelike, and have different width in different cross sections. Additionally, toggle 26,28 can also have different thickness.Shape, width and the thickness of toggle is selected The different Mass Distribution of toggle, rigidity and the requirement of other mechanical performances can be met.Such as, according to of the present utility model One alternative embodiment, the thickness of toggle 26,28 as shown in figure 12 is less than scanning board 40 and the thickness of balance ring 70 Degree.

According to this utility model one preferred embodiment, scanning board 40, balance ring 70 and toggle 26,28 use with The identical semi-conducting material of substrate 10 is made.One mirror surface 50 is positioned on the end face 401 of scanning board 40.Balance ring 70 second surfaces 702 with a first surface 701 and relative first surface 701, a coil 60 is positioned at balance ring On the first surface 701 of 70.According to this utility model one preferred embodiment, reflecting mirror 50 includes being deposited on scanning board 40 A platinum reflecting surface of end face 401.One Guan Bi circuit coil 60 is arranged at the first surface 701 of balance ring 70.Root According to a preferred embodiment of the present utility model, coil 60 includes having a conductive material (such as, golden, copper or aluminum etc.) One Guan Bi circuit winding.

As illustrated in figures 11 and 13, according to an embodiment of the present utility model, capacitive sensing apparatus includes along B-B The electric capacity C11 and electric capacity C21 of line diagonal setting.Wherein, electric capacity C11 includes movable electrode 411 and a fixing electricity Pole 111, movable electrode 411 is arranged on the end face 401 of scanning board 40, is positioned at the first limit (Figure 13 institute of the first axle Show left one side of something of scanning board 40), and distance the first axle one distance.Fixed electrode 111 is arranged at the chamber of substrate 10 On the sidewall 30 of body 20, and it is adjacent to movable electrode 411.Movable electrode 411 and fixed electrode 111 are at scanning board 40 static or rotate during there is certain area coverage.In the same manner, electric capacity C21 includes movable electrode 421 He One fixed electrode 122, movable electrode 421 is arranged on the bottom surface 402 of scanning board 40, is positioned at the second limit of the first axle (right one side of something of scanning board 40 shown in Figure 13), and distance the first axle one distance.Fixed electrode 122 is arranged at base On the sidewall 30 of the cavity 20 at the end 10, and it is adjacent to movable electrode 421.Movable electrode 421 and fixed electrode 122 exist Scanning board 40 static or rotate during there is certain area coverage.In other embodiments, electric capacity C11 and/or Electric capacity C21 can not be arranged along line B-B, say, that electric capacity C11 and/or electric capacity C21 can deviate line B-B and set Put.Such as, electric capacity C11 can be arranged on above line B-B as shown in figure 11 and the line A-A left side region (but not On line A-A), electric capacity C21 then can be arranged on the district below line B-B as shown in figure 11 and on the right of line A-A Territory (but not on line A-A).Certainly, two electric capacity arranged along line B-B diagonal make capacitive sensing apparatus The accuracy of sensing scanning board angular displacement is the most reliable.According to this utility model, the fixed electrode 111 of electric capacity C11 is permissible On the plane of flattening of the first type surface 11 being arranged on substrate 10 (as shown in figure 13), i.e. the fixed electrode 111 of electric capacity C11 Horizontal plane flush with the first type surface 11 of substrate 10, it is also possible to be arranged on the side of first type surface 11 1 distance away from substrate 10 On wall 30.

As shown in FIG. 11 and 12, according to an embodiment of the present utility model, capacitive sensing apparatus includes along line A-A The electric capacity C31 and electric capacity C41 of diagonal setting.Wherein, electric capacity C31 includes movable electrode 431 and a fixed electrode 131, movable electrode 431 is arranged on the first surface 701 of balance ring 70, is positioned at first limit (Figure 12 of the second axle Left one side of something of shown balance ring 70), and distance the second axle one distance.Fixed electrode 111 and the master meter of substrate 10 Face 11 flushes, and is adjacent to movable electrode 431.Movable electrode 431 and fixed electrode 131 are static at balance ring 70 Or during rotating, there is certain area coverage.Similarly, electric capacity C41 includes that a movable electrode 441 and is fixed Electrode 142, movable electrode 441 is arranged on the second surface 702 of balance ring 70, is positioned at the second limit (figure of the second axle Right one side of something of balance ring 70 shown in 12), and distance the second axle one distance.Fixed electrode 142 is arranged at substrate 10 Cavity 20 sidewall 30 on, and be adjacent to movable electrode 441.Movable electrode 441 and fixed electrode 142 are in balance Ring 70 static or rotate during there is certain area coverage.In other embodiments, electric capacity C31 and/or electric capacity C41 can not be arranged along line A-A, say, that electric capacity C31 and/or electric capacity C41 can deviate line A-A and arrange. Certainly, two electric capacity arranged along line A-A diagonal make the accurate of the sensing scanning board angular displacement of capacitive sensing apparatus Property is the most accurate.According to this utility model, the fixed electrode 131 of electric capacity C31 can be arranged on the first type surface of substrate 10 On the plane of flattening of 11 (as shown in figure 12), i.e. the horizontal plane of the fixed electrode 131 of electric capacity C31 and the master of substrate 10 Surface 11 flushes, it is also possible to be arranged on the sidewall 30 of first type surface 11 1 distance of substrate 10.

It is apparent that capacitive sensing apparatus also include the movable electrode 411 being coupled in electric capacity C11 and electric capacity C21 can One electric conductor of moving electrode 421, and it is coupled in movable electrode 431 and the movable electrode of electric capacity C41 of electric capacity C31 Another electric conductor (not shown in accompanying drawing) of 441, with this make electric capacity C11 and electric capacity C21 and electric capacity C31 and Electric capacity C41 respectively constitutes the first series capacitance group and the second series capacitance group.Here, electric conductor can be to be embedded in respectively A wire in scanning board 40 and balance ring 70 or a conductive adhesive tape.Those skilled in the art can be according to scanning board Electric conductor is selected and sets by the practical situation such as size or material.

Electric capacity C11, C21 are used for sensing the scanning board 40 rotation around the first axle along line A-A shown in Fig. 1.Separately Outward, the first sensing circuit that the first series capacitance group constituted with by electric capacity C11 and electric capacity C21 couples is set as producing The first magnitude of voltage corresponding to a capacitance of the first series capacitance group.Electric capacity C31, C41 be used for sense balance ring 70 around Rotation along the second axle of line B-B shown in Fig. 1.Additionally, constitute with by electric capacity C31 and electric capacity C41 second connects Second sensing circuit of capacitance group coupling is set as producing the second voltage of the capacitance corresponding to the second series capacitance group Value.In the first axle rotation process, electric capacity C11, the movable electrode 411 of C21, C31, C41,421,431, 441 with fixed electrode 111, the area coverage between 122,131,142 can change, and this change will make by The first series capacitance group that electric capacity C11 and electric capacity C21 are constituted and the second string being made up of electric capacity C31 and electric capacity C41 The capacitance of connection capacitance group changes, so that the first magnitude of voltage of the first sensing circuit output and the second sensing circuit Second magnitude of voltage of output also produces corresponding change.The movable electrode 411,421 of electric capacity C11, C21 and fixed electrode Between 111,122, the size of area coverage indicates the scanning board 40 first type surface 11 relative to substrate 10 around the first axle Angular displacement.Movable electrode 431,441 and the fixed electrode 131 of electric capacity C31, C41, between 142, area coverage is big The little balance ring 70 first type surface 11 relative to substrate 10 that indicates is around the angular displacement of the second axle.The micro scanner of Figure 13 In the micro scanner 100 of the dependent Series capacitance group in 200 and the set-up mode of sensing circuit and function and Fig. 1 First series capacitance group C₀1 and second series capacitance group C₀2 first sensing circuit corresponding with it and the second sensing circuits Set-up mode identical with function, by accompanying drawing, series capacitance group and the sensing circuit of the present embodiment are not entered at this The description that row is detailed, it may be necessary to refering to Fig. 4, Fig. 5, Fig. 8 and Fig. 9.

As is illustrated by figs. 11 and 12, in order to improve the sensing precision of capacitive sensing apparatus further, according to this reality By another novel embodiment, capacitive sensing apparatus also includes electric capacity C51 and the electric capacity C61 arranged along line A-A diagonal. Wherein, electric capacity C51 includes movable electrode 451 and a fixed electrode 141, and movable electrode 451 is arranged at balance ring 70 First surface 701 on, be positioned at second limit (right one side of something of balance ring 70 shown in Figure 12) of the second axle, and distance Second axle one distance.Fixed electrode 141 flushes with the first type surface 11 of substrate 10, and is adjacent to movable electrode 451. Movable electrode 451 and fixed electrode 141 are static at balance ring 70 or have certain area coverage during rotating. Similarly, electric capacity C61 includes movable electrode 461 and a fixed electrode 132, and movable electrode 461 is arranged at balance ring On the second surface 702 of 70, it is positioned at first limit (left one side of something of balance ring 70 shown in Figure 12) of the second axle, and away from From the second axle one distance.On the sidewall 30 of the cavity 20 that fixed electrode 132 is arranged at substrate 10, and be adjacent to can Moving electrode 461.Movable electrode 461 and fixed electrode 132 are static at balance ring 70 or have during rotating certain Area coverage.

As illustrated in figures 11 and 13, in order to improve the sensing precision of capacitive sensing apparatus further, according to this reality By novel another embodiment, capacitive sensing apparatus also includes electric capacity C52 and the electric capacity C62 arranged along line B-B diagonal. Wherein, electric capacity C52 includes movable electrode 452 and a fixed electrode 121, and movable electrode 452 is arranged at scanning board 40 End face 401 on, be positioned at second limit (right one side of something of scanning board 40 shown in Figure 13) of the first axle, and distance first Axle one distance.Fixed electrode 121 flushes with the sidewall 30 of the cavity 20 of substrate 10, and is adjacent to movable electrode 452.Movable electrode 452 and fixed electrode 121 static at scanning board 40 or rotate during there is certain coverage rate Long-pending.Similarly, electric capacity C62 includes movable electrode 462 and a fixed electrode 112, and movable electrode 462 is arranged to be swept Retouch on the bottom surface 402 of plate 40, be positioned at first limit (left one side of something of scanning board 40 shown in Figure 13) of the first axle, and Distance the first axle one distance.On the sidewall 30 of the cavity 20 that fixed electrode 112 is arranged at substrate 10, and it is adjacent to Movable electrode 462.Movable electrode 462 and fixed electrode 112 static at scanning board 40 or rotate during have one Fixed area coverage.

When capacitive sensing apparatus includes electric capacity C11, when C21, C52, C62, can by correspondence by electric capacity C11, The series electrical capacitance output that the magnitude of voltage of the series capacitance group output that C21 is constituted and correspondence are made up of electric capacity C52, C62 Magnitude of voltage coupled to a differential amplifier circuit in difference mode signal mode.When capacitive sensing apparatus includes electric capacity C31, C41, When C51, C61, it is also possible to the magnitude of voltage of the series capacitance group output that correspondence is made up of electric capacity C31, C41 and correspondence The magnitude of voltage of the series electrical capacitance output being made up of electric capacity C51, C61 coupled to another differential amplification in difference mode signal mode Circuit.Shown in structure, set-up mode and function and Fig. 6 and Figure 10 of the two differential amplifier circuit Differential amplifier circuit is same or similar, therefore is not specifically described this by relevant drawings.

According to an embodiment of the present utility model, electric capacity C31, C41 as shown in figure 12 or electric capacity C51 is only set, C61 also can sense the angular displacement around the second axle along line B-B shown in Figure 11 of the balance ring 70.Similarly, only arrange such as figure Electric capacity C11, C21 shown in 13 or electric capacity C52, C62 also can sense scanning board 40 around along line A-A shown in Figure 11 The angular displacement of the first axle.According to a preferred embodiment of the present utility model, capacitive sensing apparatus can arrange electricity simultaneously Hold C11, C21, C52, C62 with sensing scanning board 40 around the angular displacement of the first axle along line A-A shown in Fig. 1, and And electric capacity C31 is set simultaneously, C41, C51, C61 balance ring 70 around the second axle along line B-B shown in Fig. 1 with sensing Angular displacement.Based on this, those skilled in the art can comprehensively sensing accuracy, manufacture difficulty and Productive statistics etc. be in many ways Face factor, selects accordingly the quantity of the electric capacity in capacitive sensing apparatus and arranges.

Capacitive sensing apparatus described in the utility model is a kind of noncontacting proximity sensor.According to this utility model, should Noncontacting proximity sensor uses capacitive sensing technology to determine that the one scan plate in micro scanner is around orthogonal two The angular displacement of axle.According to this utility model, this capacitive sensing apparatus includes being arranged at scanning board and/or is connected with scanning board On one balance ring can dynamic condenser and be arranged at a suprabasil fixed capacity.According to a preferred embodiment, capacitance sensing Device can also include a differential amplifier circuit.According to another embodiment, it is permissible that the electric capacity of capacitive sensing apparatus arranges quantity Reasonably select and arrange, to obtain the sensing result of high accuracy.

According to this utility model, this capacitive sensing apparatus with there is a floating equilibrium ring assemblies or a floating scanning board MEMS micro scanner is compatible.In this type of MEMS micro scanner, this Gimbal Assembly or scanning board It is suspended in the magnetic field resulted from around a cavity of substrate.Levitated equilibrium ring assemblies or scanning board in magnetic field, thus Without having a physical connection between scanning board or balance ring and perimeter frame, thus substantially increase scanner at height scanning frequency The scan performance of the aspects such as rate, high scanning resolution and high scan angles.According to a capacitive sensing apparatus of the present utility model With a MEMS micro scanner compatibility that can bear altofrequency and big amplitude driving.According to described in the utility model Capacitive sensing apparatus has a wide range of applications field.

Although different embodiment is combined for this utility model and is described with reference to relevant drawings, but this area Those of ordinary skill can make different amendments based on foregoing description of the present utility model.Such as, new according to this practicality One capacitive sensing apparatus of type is not limited to be implemented in having as above that a MEMS of a floating structure is micro-sweeps Retouch in device.According to a capacitive sensing apparatus of the present utility model it can also be provided that sensing is at a MEMS micro scanner In the angular displacement of one scan plate.Additionally, paper can be being included according to the electric capacity of a capacitive sensing apparatus of the present utility model The electric capacity that dielectric appearance, ceramic condenser, thin-film capacitor and electrolytic etching of metal electric capacity equal-volume are less.

Claims

1. a capacitive sensing apparatus, it is positioned at a micro scanner, and described micro scanner has the cavity being positioned at a substrate Interior one scan plate, described cavity has the sidewall surrounding described scanning board, and described scanning board has one first Surface and the second surface relative to described first surface, and be set as responding a driving to turn around one first axle One second dynamic and vertical with described first axle axle rotates, it is characterised in that described capacitive sensing apparatus includes: One first electric capacity, comprising:

One movable electrode, is arranged on the described first surface of described scanning board, is positioned at the one of described first axle First axle one distance described in one back gauge；And

One fixed electrode, is arranged on the described sidewall of described substrate cavity and neighbouring described movable electrode, and with Described movable electrode is static at described scanning board or has certain area coverage in rotation process；

One second electric capacity, comprising:

One movable electrode, is arranged on the described second surface of described scanning board, be positioned at described first axle with institute State one second limit that the first limit is relative, and away from described first axle one distance；And

One first electric conductor, be coupled in the described movable electrode of described first electric capacity and described second electric capacity described movably Electrode so that described first electric capacity constitutes one first series capacitance group with described second electric capacity, and

One first sensing circuit, it has a first input end, one second input and an outfan, described first defeated Enter end and be coupled respectively to the described fixed electrode and described second of described first electric capacity with described second input The described fixed electrode of electric capacity, described sensing circuit is set as producing corresponding to described first series capacitance group One first magnitude of voltage of a capacitance to described outfan.

Capacitive sensing apparatus the most according to claim 1, it is characterised in that described capacitive sensing apparatus includes:

One the 3rd electric capacity, comprising:

One movable electrode, is arranged on the described first surface of described scanning board, is positioned at described the of described first axle Two limits, and away from described first axle one distance；And

One fixed electrode, is arranged on the described sidewall of described substrate cavity and neighbouring described movable electrode, and with institute State that movable electrode is static at described scanning board or has certain area coverage in rotation process；

One the 4th electric capacity, comprising:

One movable electrode, is arranged on the described second surface of described scanning board, is positioned at described the of described first axle On one side, and away from described first axle one distance；And

One second electric conductor, the described movable electrode being coupled in described 3rd electric capacity can galvanic electricity with described the described of 4th electric capacity Pole so that described 3rd electric capacity constitutes one second series capacitance group with described 4th electric capacity, and

One second sensing circuit, it has a first input end, one second input and an outfan, described first input End and described second input are coupled respectively to the described fixed electrode of described 3rd electric capacity and described 4th electric capacity Described fixed electrode, described sensing circuit be set as produce corresponding to described second series capacitance group one electricity One second magnitude of voltage of capacitance is to described outfan.

Capacitive sensing apparatus the most according to claim 2, it is characterised in that described capacitive sensing apparatus includes that one is differential Amplifying circuit, has a first input end and one second input, and described first input end is coupled in described first The described outfan of sensing circuit, described second input is coupled in the described output of described second sensing circuit End, described differential amplifier circuit is set as exporting a magnitude of voltage, and described magnitude of voltage corresponds to described first magnitude of voltage And described second magnitude of voltage.

One the 3rd electric capacity, comprising:

One movable electrode, is arranged on the described first surface of described scanning board, is positioned at the one of described second axle On one side, and away from described second axle one distance；And

One fixed electrode, is arranged on the described sidewall of described substrate cavity and neighbouring described movable electrode, and with

Described movable electrode is static at described scanning board or has certain area coverage in rotation process；

One the 4th electric capacity, comprising:

One movable electrode, is arranged on the described second surface of described scanning board, be positioned at described second axle with institute State one second limit that the first limit is relative, and away from described second axle one distance；And

One second electric conductor, be coupled in the described movable electrode of described 3rd electric capacity and described 4th electric capacity described movably Electrode so that described 3rd electric capacity constitutes one second series capacitance group with described 4th electric capacity, and

One second sensing circuit, it has a first input end, one second input and an outfan, described first defeated Enter end and be coupled respectively to the described fixed electrode and the described 4th of described 3rd electric capacity with described second input The described fixed electrode of electric capacity, described sensing circuit is set as producing one corresponding to described second series capacitance Second magnitude of voltage of one capacitance of group is to described outfan.

Capacitive sensing apparatus the most according to claim 4, it is characterised in that described capacitive sensing apparatus includes:

One the 5th electric capacity, comprising:

One movable electrode, is arranged on the described first surface of described scanning board, is positioned at the described of described second axle Second limit, and away from described second axle one distance；And

One the 6th electric capacity, comprising:

One movable electrode, is arranged on the described second surface of described scanning board, is positioned at the described of described second axle First limit, and away from described second axle one distance；And

One the 3rd electric conductor, be coupled in the described movable electrode of described 5th electric capacity and described 6th electric capacity described movably Electrode so that described 5th electric capacity constitutes one the 3rd series capacitance group with described 6th electric capacity, and

One the 3rd sensing circuit, it has a first input end, one second input and an outfan, described first defeated Enter end and be coupled respectively to the described fixed electrode and the described 6th of described 5th electric capacity with described second input The described fixed electrode of electric capacity, described sensing circuit is set as producing corresponding to described 3rd series capacitance group A third voltage value of a capacitance to described outfan.

Capacitive sensing apparatus the most according to claim 5, it is characterised in that described capacitive sensing apparatus includes that one is differential Amplifying circuit, has a first input end and one second input, and described first input end is coupled in described second Outfan described in sensing circuit, described second input is coupled in outfan described in described 3rd sensing circuit, institute Stating differential amplifier circuit and be set as exporting a magnitude of voltage, described magnitude of voltage is corresponding to described second magnitude of voltage and described Third voltage value.

Capacitive sensing apparatus the most according to claim 1, it is characterised in that described micro scanner includes a balance ring, It is positioned at the cavity of described substrate and surrounds described scanning board, and described balance ring has a first surface and relatively In a second surface of described first surface, and described balance ring is by least one toggle with described scanning board even Connecing, wherein, described scanning board is set as that the first axle of at least one toggle described in be parallel to rotates, described flat Weighing apparatus ring is set as that the second axle around being perpendicular to described first axle rotates, and described capacitive sensing apparatus includes:

One the 3rd electric capacity, comprising:

One movable electrode, is arranged on the described first surface of described balance ring, is positioned at the one of described second axle On one side, and away from described second axle one distance；And

One fixed electrode, is arranged on the described sidewall of described substrate cavity and neighbouring described movable electrode, and with Described movable electrode is static at described balance ring or has certain area coverage in rotation process；

One the 4th electric capacity, comprising:

One movable electrode, is arranged on the described second surface of described balance ring, be positioned at described second axle with institute State one second limit that the first limit is relative, and away from described second axle one distance；And

One second sensing circuit, it has a first input end, one second input and an outfan, described first defeated Enter end and be coupled respectively to the described fixed electrode and the described 4th of described 3rd electric capacity with described second input The described fixed electrode of electric capacity, described sensing circuit is set as producing corresponding to described second series capacitance group One second magnitude of voltage of a capacitance to described outfan.

Capacitive sensing apparatus the most according to claim 7, it is characterised in that described capacitive sensing apparatus includes:

One the 5th electric capacity, comprising:

One movable electrode, is arranged on the described first surface of described balance ring, is positioned at the described of described second axle Second limit, and away from described second axle one distance；And

One the 6th electric capacity, comprising:

One movable electrode, is arranged on the described second surface of described balance ring, is positioned at the described of described second axle First limit, and away from described second axle one distance；And

One fixed electrode, on the described sidewall of the cavity being arranged at described substrate and adjacent to described movable electrode, and Or rotation process static at described balance ring with described movable electrode has certain area coverage；

Capacitive sensing apparatus the most according to claim 8, it is characterised in that described capacitive sensing apparatus includes that one first is poor Dynamic amplifying circuit, has a first input end and one second input, and described first input end is coupled in described the The described outfan of two sensing circuits, described second input is coupled in the described output of described 3rd sensing circuit End, described first differential amplifier circuit is set as exporting a magnitude of voltage, and described magnitude of voltage is corresponding to described second electricity Pressure value and described third voltage value.

One the 5th electric capacity, comprising:

One movable electrode, is arranged on the described first surface of described scanning board, is positioned at the described of described first axle Second limit, and away from described first axle one distance；And

One the 6th electric capacity, comprising:

One movable electrode, is arranged on the described second surface of described scanning board, is positioned at the described of described first axle First limit, and away from described first axle one distance；And

One fixed electrode, on the described sidewall of the cavity being arranged at described substrate and adjacent to described movable electrode, and Or rotation process static at described scanning board with described movable electrode has certain area coverage；

11. capacitive sensing apparatus according to claim 10, it is characterised in that described capacitive sensing apparatus includes that one is differential Amplifying circuit, has a first input end and one second input, and described first input end is coupled in described first sense The described outfan of slowdown monitoring circuit, described second input is coupled in the described outfan of described 3rd sensing circuit, institute Stating differential amplifier circuit and be set as exporting a magnitude of voltage, described magnitude of voltage is corresponding to described first magnitude of voltage and described Three magnitudes of voltage.