CN1017383B - Capacitive pressure-sensing method and apparatus - Google Patents

Abstract

The present invention relates to a novel pressure-sensitive sensing technology and a device thereof, wherein an elastomeric conductive electrode carrying a two-dimensional array of projections is pressure-deformed against a fixed coextensive cooperative electrode to generate signals. The signals are corresponding to the dynamical stress applied to a two-dimensional surface such as tones and sounds applied to musical instruments, or visual representations. A novel drum and other music instruments embody the novel capacitive sensing technology, etc.

Description

Capacitive pressure-sensing method and apparatus

The present invention relates to pressure-sensing method and equipment, more particularly, it relates to novel bidimensional capacitive sensor and technology, particularly, but be not limited only to can be used for capacitive sensor and the technology that music and rhythmic musical instrument and response touched and be applied to other devices of a variable force on the two-dimensional surface.

Applicant Jeff Te Lipu is at United States Patent (USP) certificate the 4th, 498, No. 365 disclosed novel capacitive pressure sensors have the elastic conduction electrode of a shape bending or taper, this elastic conduction electrode be subjected to musical instrument by key excitation or other pressure the time produce deformation, and being bonded into variable capacitive relationship with the fixed electorde of isolating with this elastic electrode electrically, this capacitive pressure sensor is of great use for the operation of the single restricted area of pressure contact.In the use of explanation one keyboards for musical instruments, this sensor provides continuous sensing, with generation as electronics sound in the musical instrument, and after pressing the contact of key excitation or other pressure, even can pressure be changed, to be used as the purpose that makes the second note generation or the tone or the change of tuneization.Obviously, in other application of the similar response of needs, also be useful.

Yet, in those hope pressure is applied on the two-dimensional surface, and on the two-dimensional surface beat or knock and/or the occasion of the variation sensitivity that the particular module of response pressure or dynamic shape change exists.As specific description, by drum rod knock or wire brush scan and/or with the Different Dynamic pressure model with change on eardrum with pointing or hand scans and excites eardrum, need independent tiny point of such two dimension or regional pressure sensing in order to produce the sound that characterizes these pressure and pressure model, and convert electric signal to.In like manner, to introduce later on, specify as another, for the visible model of resetting, to have a plurality of electrodes and in conjunction with the structure of a public elastic body electrode as measuring palmmprint, fingerprint or footprint and their motion change, can designing, too will be with two-dimentional continuous dynamic sensing.

For using in touch sensor to produce sensory feedback, once an array touch sensor that excited and operated with the voltage of the resistance variations of response pressure comes the conductive elastomer pad complaint conductive elastomeric pad of development report defect for this reason, these touch sensors are exported (for example, seeing that Barry Wright company announced " Sensorflex/Astek " the 17th, 18 page in 1984) by the ranks sequential deployment with the digital signal that a multidigit is provided.Although this sensor is two-dimentional, the problem of existence has the time stability of conductance, needs in fact to be restricted with the electronic equipment of complexity and size and the area that can control owing to related pad resistance.

Therefore, an object of the present invention is to provide a kind of new improving one's methods and equipment, with thinking that this class is used and other need the occasion of similar response that such two-dimensional pressure sensing response is provided.

Another purpose is owing to use the pressure sensing result of novelty of the present invention so that novel music that comprises drum-type instrument that very big dirigibility is arranged and rhythmic musical instrument to be provided.

Also have other purposes to explain hereinafter, and more specifically describe in the appended claims.

In a word, from each side of the present invention at a glance, the present invention utilizes one to have one first electrode of array configuration and the capacitive pressure-sensing sensor of one second electrode, this first electrode comprises a thin elastic conduction plastic sheet, elastic conductive projection and adjacent area that a plurality of tight spacings are arranged on the sheet, projection protrudes from a surface of this conductive plastic film, and exerting pressure at this adjacent area by the apparent surface from this sheet to make this adjacent area compressive deformation.And this second electrode surface spreads out jointly to projection and with projection, and with a thin dielectric layer second electrode and projection is separated.Embodiment and the parts preferred and best mode that comprise bulging percussion instrument and so on will be described in detail hereinafter.

Now narrate the present invention referring to accompanying drawing, Fig. 1 is the xsect that can be used for the preferred two-dimentional capacitive pressure sensor of reality of the present invention;

Fig. 2 A-2C knocks the resulting variation of Fig. 1 sensor with what experimental technique was derived to rouse rod, and Fig. 2 D and 2E are the output that is applied to the sensor surface pressure model;

Fig. 3 A-3D is the viewgraph of cross-section of amplification of making the useful projection configuration of Fig. 1 sensor electrode;

Fig. 4 A is an isometric view of using a plurality of sensor pads or the part of rousing with the multi-region section of relatively independent effect electing property of sensitive zones to cut effectively;

Fig. 4 B is similar to Fig. 4 A, but uses the sensor electrode of single elastic body shim;

Fig. 4 C is for being all a similar diagram of the bottom of this useful drum to the embodiment of Fig. 4 A and Fig. 4 B;

Fig. 5 is the circuit diagram of the signal handling equipment that changes of the capacitive character of sensor of the musical instrument of preferred response diagram 4A and 4B, and this need tone and the signal of the sound generator of sound to produce that institute for example can produce in order to control.

Referring to Fig. 1; the pressure transducer of this optimised form comprises a thin plastics conductive rubber or other flexible elastomeric pad plate electrodes 1; preferably be configured to overlayer C on one surface of electrode 1 as the flat surfaces of one deck protectiveness of making by vibrin and so on; this point will be discussed after a while all sidedly; the another side of overlayer C (being illustrated as lower surface) is outstanding by the identical conduction resilient material and the projection 1 of bending or variable thickness or the taper of making '; these projections 1 ' by what closely separate; preferably become uniform two-dimensional array; this two-dimensional array is separated by the thin dielectric 2 that one deck preferably can slightly flexibly be out of shape with the capacitive relationship of precision, and being extended into the two-dimentional electrical conductor electrode surface 3 that spreads out jointly has capacitor sexual intercourse closely.Electrode 3 shown in the figure is positioned on immovable plate B securely, and limits the downward pressing of upper strata elastomeric pad plate electrodes with electrode 3.Electrode 1 pressing one-tenth is contacted the required capacitance variations to be measured of development with the mechanical force of immovable electrode 3.Shown in Fig. 3 A-3D for the curved surface of various projections 1 ' used or taper body respectively to be brachymemma hemisphere, the biconial pinnacle on hemispheric, band cone or taper pinnacle basically and to have a cone body that Ji Ding is rounded slightly.

When electrode 1 relative (on) surface depressed as the finger F among Fig. 1 and when being out of shape, discovery at its taper thickness of compression when producing bigger capacitive effects, curved surface under the compression finger tip model or taper projection 1 ', will be with being that irrelevant separately selectivity distortion projection correspondingly is depressed and is out of shape basically, so that the profile of imitation finger and apply various forms of power by the different piece of finger tip near each projection under the finger tip.Output terminal 4 at this variable condenser 1-1 '-2-3 described as follows is connected suitable electronic installation with 5, the application of force of finger tip and move will produce the capacitive character variation of being processed into the signal that can control the sound that produces audio frequency or sound easily.Its audio frequency effect is proportional to applied pressure, and corresponding to finger tip beat and knock and corresponding to the dynamic pressure model of the surface area of mobile finger tip on the electrode pads surface 1.Employing is placed in the overlayer or the top cover C of the drum on silicon rubber or other elastomeric pad electrode 1, provides to prevent to make dirty and abrade pad and electrostatic attraction dirt.In addition, overlayer also is used as electric insulator and spacer to prevent the body capacity effect system and to prevent to introduce noise, overlayer also plays " dispenser " lid, when acting on local power (for example tip of drum rod) may very big occasion be useful, so as the compression deformation set that had both limited pad also by will knock be dispersed in capacitor than on the large tracts of land so that amplifying signal mechanically.

Now referring to the embodiment of Fig. 4 A, with the drum rod or wire brush knocks bulging teleblem and/or when sweeping with bulging rod, brush, finger or hand on eardrum, find that each capacitive variation on two-dimensional surface of so producing can be processed into the model of sound and response relation corresponding with added pressure model and that be directly proportional basically by signal, and preferably the continuity pressure sensing with the described single-sensor spare of said patent makes the model of this sound respond added pressure model in direct ratio ground basically.As said patents state, for the effect of special sound or sound, comprise during pushing the variation effect of second beating effect and sound, can get in touch Fig. 5 to set up the various signal threshold values that press degree is used.

Fig. 2 A-2C illustrates the visual representation of the output signal that obtains with experimental technique, these output signals are because drum rod makes electric capacity produce with the variation of the elasticity capacitive electrode structure of this two-dimensional shapes the light, medium of eardrum with heavy knocking or beat, and show on the print-out device of connection electrode.The generation of signal will be narrated in hereinafter getting in touch Fig. 5.Electrode 1-1 ' is made by the flexible plastic sheet of the silicon rubber of filling carbonaceous, thick about 1/10th inches and have about 60 hardness of losing Lip river sclerometer unit of sheet, have a two-dimensional array closely separate protrude about 0.06 inch moulding projection (100 projections per square inch) from thick about 0.035 inch web 1.Other electrode 3 is made by the aluminium foil of 1 mil thick and is had a dielectric layer 2 that " kapton " that thickness approximately also is 1 mil (polyimide plastic of E.I.Du Pont Company) made.

Fig. 2 D and 2E illustrate the pattern effect of surface pressing, and the former responds the sensing surface output (unit is selected arbitrarily) that applies strong area on it, and the latter illustrates that output is the function that is applied to the power of transducing part.

In using referring to the bulging class of Fig. 4 A back, edge clamp device 9 can be with assembly with may be in conjunction with the overlay 7(Fig. 4 A and the 4C of ground plane) be fixed together.As introducing after a while, if needed, the B ' of base plate B downside locates in the electronic installation Gozino chart 4 that signal Processing can be used.

The separate sections of the top cover C of drum or zone are configurable as Fig. 4 A and 6 ', 6 " wait the place; with as the different of this zone or section place and effect independently; and between the zone, dispose the isolator 10 of the metal " star " of a moulding, the star isolator is connected to bulging top cover C so that a kind of structure that can prevent interregional cross-talk to be provided with a bonding coat 8.

Therefore, basic system architecture is a printed circuit board, (1) for example (by wire mark on a polyester film such as mylar (Mylar)) contain the bottom sensing electrode 3, connect drive signal to the device of the elastic body electrode 1-1 ' on top be connected to the device of main electronic equipment; (2) a slice may with or may be adhered to or the dielectric 2 of wire mark to the printed circuit board (PCB) without bonding agent; (3) upper electrode (1) made of veined as mentioned above conductive elastomer; (4) one deck loam cake or drum top cover C; (5) provide the electronic equipment of pumping signal to elastic body electrode 1, it also provides anti-phase pumping signal other side to sensing capacitor, the capacitance variations in monitoring sensor zone and be useful electronic signal with these change transitions.Monolithic elastomeric sheets electrode 1-1 ' is following among Fig. 4 B can have a plurality of electrodes 3 also to produce some isolated areas, and this point can be introduced on more detailed layer ground after a while.

As the total vertical dislocation in the system of present structure is 1/16 inch.Need with so that the power of a certain regional displacement wants approximately proportional with the signal that is produced at least, and so that it as the mode of an efficient pressure sensor power " is given back ".Described system can mechanically reach when needed the change of electronics mode with conversion in a big way power and have darker actuating distance so that for its various application occasions, be useful.

The planar nature of system means that the sensitization area is littler to the ratio of the sensing unit total area, and the sensitization signal that maybe should distinguish rest capacitance with respect to " substrate " is also little.Because what use is big zone, so this substrate electric capacity also is big.In addition, rubber projection 1 ', just can not increase signal because additional power or pressure are arranged in case be fully depressed, because vertical stroke is limited, knocking also of high speed small size comes to an end rapidly.For the semirigid mylar overlayer C of the amplification usefulness of machinery is that small size is implemented slight and fierce these two kinds and knocked and make the additional area of capacitor to be utilized, produced differentiable " beaing " in a big way.The area that can support the adjacent capacitor of utilization is implemented area to sensitization ratio is implemented area with sensitization and is become and reduce greatly, does not show till the amplification effect up to the same big enforcement area with this region area.In other words, use the amplification of machinery, power that can be in a big way and the product of area (pressure or knock) boil down to is changed than the effective energy that sensor/electronic equipment of close limit makes up.

" web " that it should be noted that conductive rubber electrode 1-1 ' and thickness are adjustable, and to be decided to be the web role of the system that is fit to a special use similar, though be not in full accord.

This structure has reduced the independent degree of surface local area really; Yet this just structure can access the signal that can compare that knocks (drum rod) and large tracts of land low velocity impact (finger) from the high speed small size.Semirigid top overlay C finishes another kind of dynamic function in drum.Drum strikes heavylier, just shows the instantaneous rigidity of De Genggao, and the capacity area of influenced (being meant that again machinery amplifies) is also just big.This tectal variation can be from not having to thin and flexible (only shielding) layer, to thin and semi-rigid (thin mylar) layer, to thicker semi-rigid layer, to rigid layer.

Last a kind of rigid layer can be used so that the area of system is insensitive in the low application that distributes on a large scale, these application examples such as weighing device or discrete crash sensor, or with the combination of other sensor stack formulas to derive the signal of deriving to the information of area sensitivity with from the bottom from top sensor to synchronous area sensitivity, perhaps multisensor piles up with at remote accurately ergometry.

The present invention in its preferred utility structure (seeing Fig. 4 A and 4B) multi-region or section electronic drum musical instrument use be embodied in its top surface have five independently knock district 6 ', 6 ", 6 " ' etc., and five CV(analog control voltages are arranged) output.To illustrate that after a while this drum music device is with 12 volts of batteries or other DC power supply, and be added on the standard setting pin post by the bulb of bottom.This system responses these two kinds of power stable and pulse, its speed of response are in the scope of a few tenths of microsecond and in the scope that frequency response just drops on kilo hertz.

Output is an aanalogvoltage, and it follows the tracks of electric capacity because of the variation of knocking or the pressing pad causes; These change are converted to drive " computer " of most of existing CV electronic drums.As previously described, the preferred electronic circuitry of working together with the sensor of Fig. 1,4A and 4B is shown in Fig. 5, and this electronic circuit uses the common base section of the embodiment as Fig. 4 A and 4B of Fig. 4 C.In a kind of equipment of practicality, the sensor body of this device for example is that the cavity B ' of 1 inch thick particle board disk B dish carves at the back side of electronic installation.Be placed with the P.e.c. sheet 11 that a mylar sheet that obtains as cross cutting is made on the disk, on the sheet wire mark pattern of conduction so that be five zones 6 ', 6 ", 6 " ' or the like five bottom electrode surface 3 are provided.Pumping signal is connected to elastic body electrode 1-1 ', conductor 4 with 5 in order to be connected these electrodes to electronic installation E.Its trace is along a barrier film " afterbody " 11 ' carry out, and " afterbody " encases electronic installation cavity B ' around the device body.Thereafter on electrode zone 3 wire mark a kind of as dielectric layer 2 with urine gastral cavity be the material of matrix.This one deck also preferably wire mark on afterbody so that insulation to be provided.On the P.e.c. sheet, placed the elastic body electrode 1-1 ' and the star isolator 10 of five cross cuttings.This star isolator is fastened on one's body the device with several securing member F as screw by the P.e.c. sheet.This is electrically connected to model 4 five electrodes just simultaneously with electrode 1-1 ' arrangement in position then so that drive signal to be provided.

Spacer ring 12 is placed around the periphery of assembly, has placed the viscosity film 8 of cross cutting on the star isolator, and top cover C is placed on the assembly, then is placed on the bottom faces as yet the not veneer circle 9 of swaged forging.The reversing assembly is installed overlay 7, and the swaged forging of veneer circle is become its final configuration.Five accessory power outlets and power socket J and two potentiometer P have been installed on access panel 13, and the terminals of all these sockets are all indicated at Fig. 5 after a while.These sockets are connected to the electronic installation E that is contained on the B ' of access panel bottom.Then the partition afterbody is linked electronic installation, and access panel is fastened to device on one's body to finish the installation of assembly with the tommy 14 that is fastened on the appropriate location.

If use the unitary resilient body gasket-type of figure 4B, cross cutting closes that elastic body electrode, star isolator and viscosity film have not existed and replaces with the molded gasket of a monoblock, stipulated five by solid conductive rubber 1 on the molded gasket of monoblock " the zone of the separated electrode 1-1 ' of fragment.Drive securing member and pass these solid sections and P.e.c. sheet and enter the device body simultaneously, the assembly pin is fixed on the appropriate location, and conductor 4 is linked electrode 1-1 '.

The present invention is being applied in single area sensor, significant novelty provided by the invention be its can (1) from the surface the identical input of difference produce identical signal, (2) the synthetic area and the pressure of being had a few on the while shift surface, and (3) provide continuous output, and it and lip-deep static pressure model or dynamic pressure model are proportional.That can not be distinguished has (a 1) pressure input position in its surface, and (2) are added in the power that arbitrary specified point is gone up on its surface, or (3) are actually or area-pressure model large tracts of land/low dynamics small size/great dynamics.In order to set up this information,, need to use a plurality of second electrodes as what will narrate after a while.

Output is an aanalogvoltage, and it is followed the tracks of because of the changes in capacitance of knocking or the pressing pad causes; These change are converted to drive " computer " of most of existing CV electronic drums.As previously described, be shown in Fig. 5 in order to the preferred electronic circuitry of working together with the sensor of Fig. 1,4A and 4B, this electronic circuit uses high-frequency alternating current potential source, and measures the liquidity of alternating current.This liquidity is provided by equation I=2 π EFC, and I is to be that the electric current of unit flows with the ampere in the formula, E be add the voltage of interchange (being made as sine wave), F is its frequency, C is to be the electric capacity of the sensor 1-1 '-2-3 of unit with the farad.The exemplary value of these variablees in electronic drum of the present invention is used is as follows:

The E=8 volt

The F=100 kilohertz

The C=300 micromicrofarad

The I=1.0 milliampere

So the big smallest number that electric current flows represent the instantaneous flow of electric capacity, also reflect the power that is added on the sensor and the instantaneous product of area simultaneously.Several method is arranged in order to " deducting " no exist when stressed " substrate electric capacity ".A kind of preferable methods is to apply a numerical value by the fixed condenser that a numerical value equals substrate electric capacity to equate but 180 ° of anti-phase voltages are arranged, and connect this output that is combined to sensor, under static state, the current canceling of two capacitors and provide the net current of null value.When pressure increased the flows through sensor electric current, net current leaves null value to be increased, and provides useful output.

The sinusoidal wave power oscillator of pushing off that a capacitor C ' by two transistor T1 and T2, network resistor R1-R5, a tapped power choke coil CT and a parallel connection forms is showed at Fig. 5 top.Resonant frequency of combination results of coil CR inductance (250 milihenry) and capacitor C ' (0.1 microfarad) is about 100 kilo hertzs resonance oscillations loop.Base stage is to the resistance R 3 of collector and R5(22 kilohm) starting is provided and keeps the required feedback of vibration, and base stage is to emitter R2 and R4(4.7 kilohm) the base stage blasting of limit transistor.Resistance in series R1(470 ohm) simulation-current source is to improve the sine wave of vibration almost ideal (about 1% distortion).Because the center tap of coil CT is a ground connection, the sine wave that end turn provides accurate inverted amplitude to equate to other circuit.Oscillator will be delivered to the common board of sensor (for example conductive rubber pad 1-1 ' of Fig. 4 B) with the output of " excitation output (Drive Out) ", and the signal processing circuit that now will explain is delivered in the output of reverse oscillator.

The same circuits that remaining circuit is used by five sensor pads of five confessions or sections of sensors is formed, for sensor (pad) #1(for example be section 6 ') circuit of usefulness now will be illustrated.Pressure transducer externally is connected and is marked with between " excitation output " and " pad 1 input " (Pad 1 In).So the capacitive current that is proportional to the electric capacity of sensor flows into " Pad 1 In " end.Simultaneously, flow to " Pad 1 In " from resistance-capacitance network combination by a series connection of the inverted capacitance electric current of oscillator relative side (wherein resistor numerical value is fixed, capacitor C " numerical value can on whole limited scope, change).In fact, cross, adjust capacitor and make its numerical value equal the substrate electric capacity of sensor as explained earlier.By taking into account the limited resistance of conductive rubber pad 1-1 ', this resistance more disappears two electric currents generations completely mutually.Complete balance is only at C, and " and the resistance Shi Caineng that is complementary reaches.In practice, resistance is a fraction of resulting impedance, so resistors match is not too important (20% resistance mismatch has only little influence) accurately.

Because pressure is applied to sensor, the net current that flows into " Pad 1 In " end leaves null value to be increased.The mobile resistor R that develops into of this electric current " (4.7K) the little alternating voltage at two ends.This alternating voltage is by a diode D(IN270 germanium tube) rectification, and the DC voltage of gained remains on 0.010 μ F(microfarad) on the capacitor of (mark in the drawings).Use germanium diode D to avoid silicon diode because they have the forward voltage than higher (0.6 volt) to fall caused threshold affects.In the time that applies big pressure, the positive direct-current voltages that is based upon 0.01 μ F capacitor two ends is also higher.Applying in the time of less pressure, the electric charge of capacitor leaked lentamente by diode in several milliseconds time.The peak value 0.01 μ F capacitor can temporarily keep-up pressure by this way.Smaller condenser voltage (general less than one volt) is by six times of an operational amplifier A (LM358) and feedback network Rf and Rf ' (for example being respectively 100K and 22K) increases.The output voltage of amplifier finally is added to " pad 1 output (Pad 1 Out) " by the protective resistor R of 1K ohm.So well-known, this voltage (and voltage of other 4 passages) is sent to a response by the compositor of required mode with the change voltage level.

In actual applications, the sensitivity that hope can regulating circuit and to the response of pressure.The total sensitivity of sensor can change by the output voltage that changes oscillator T1-T2, and this is to be finished by the supply voltage that changes oscillator, among the figure externally with a potentiometer P1(1K ohm) receive 3Sens.Hi " (sensing height)." Sens.Wipe " (sensing is swept and smeared) and " Sens.Low " (sensing is low) are respectively brought in and are finished.470 ohm resistor restriction regulated quantity receiving " Sens.Low " end is at 3 to 1 range.Change " Thresh.Wipe " (threshold value is swept and smeared) DC voltage at end place and also have the influence of threshold value.When this voltage was zero, final output voltage was the six times of copies strictly according to the facts that appear at the commutating voltage at 0.01 μ F filter capacitor two ends.Because making it is just can increase from null value when, output voltage (it can not be negative value) will be by the time increased the voltage threshold of the voltage that surpasses relevant " Thresh Wipe " end (bottom left of Fig. 5) by the voltage of rectification.This also can bring in by potentiometer P to three " Thresh " that externally connects a 1K ohm and finish.The 15K resistor threshold limit that is connected to " Thresh.Hi " (threshold value height) end is adjusted in useful range.

Sum up the operation of Fig. 5, therefore oscillator signal (100K is conspicuous) is added to all conductive rubber electrodes by " Drive Out ".Amplitude that should " excitation " signal is controlled by the potentiometer that is connected to three terminals " Sens.Hi, Low and Wipe(r) ".Second electrode 3 that is each regional usefulness of five sensitive zones is connected to one of five duplicate circuits by marking " Pad 1 " to " Pad 5 ".These circuit are that the alternating voltage at the resistor two ends of 4.7K comes " measurement " stream electric current by the alternating current capacitive current transitions that will flow through each sensor.This alternating voltage is converted to DC voltage by diode D earlier, is amplified then, and delivers to accessory power outlet by " Pad Out " end, and each these circuit all receives the pumping signal of paraphase.Each variable condenser is adjusted to two pumping signals and disappears, and makes capacitive current (thereby the output of the voltage of each stationary system) as much as possible near zero." minimum signal that can produce a response can be controlled by adjusting ' threshold value ' potentiometer ".

When pressure was applied to a sensor region, electric capacity was changed, and capacitive current increases, and the DC voltage rising on the output terminal.When removing pressure, output gets back to zero.Shown in Fig. 2 A-C rapidly knock " pulse " that produces lifting rapidly, and the pressure proportional slow increase of voltage that only produces output terminal slowly.As previously mentioned, this analoglike output (being called as CV in music industry) is connected to the sound generator of accepting the CV input, and the control level of its sound is decided by the performance of sound generator fully.

" computer " of major heading sound generator CV electronic drum, these " computers " reveal different responses according to their input circuit property list, for instance, if the input of " computer " is an AC coupling, then has only the powerful generation that (analog AC of direct current output herein) will cause sound of knocking.But as " computer " input is DC coupling, and then arbitrary signal that surpasses the special voltage threshold value all will produce sound.Electronic drum of the present invention produces special effect in this system just, because it is different with conventional piezo controller, system of the present invention can keep a voltage that is proportional to pressure.The pressure of keeping on the pad remains on the threshold voltage of " computer " output voltage, the continuous sound or the sound of repeated trigger just may occur.If tone changes because of the voltage amplitude of input signal, then the fluctuating of pad upward pressure just produces the variation of corresponding acoustic tones.

As previously mentioned, early stage electronic drum controller (drum pad) uses piezoelectric crystal as transducer.And transducer of the present invention can produce with respect to one of an absolute baseline continuous signal, piezoelectric transducer produces the momentary signal that is proportional to rate of change, when physically distortion, transducer just produces a voltage, and, transducer is got rapider and rapider by " bending ", the voltage of generation is just higher.Yet distortion one stops, even transducer remains on bending position, they also can stop to produce voltage, and makes output reduce to zero.This is a reason for this reason, and early stage transducer and difference of the present invention are that the former can not provide successive control according to the pressure after knocking along with startup.In addition, because by rate of change work, being out of shape slowly, early stage transducer do not produce useful signal.For this reason, their suitable especially conducts only are applied in the transducer that needs the trigger pip occasion, and this signal will hit and could produce by effectively striking, but " when hope has stepless control sound ", their suitable especially controllers as the keyboard shape.

Therefore, when device of the present invention is knocked with a drum rod, can produce the similar output waveform that is produced to the conventional electrical drum controller that uses piezoelectric crystal as transducer, different with piezoelectric system.System of the present invention can produce the signal that is proportional to residual pressure continuously after startup is knocked, allow the sonorific device of stepless control.In addition, it is the less dynamic force of conversion change effectively, and this power is to be not enough to produce useful signal from piezoelectric system.

Controller of the present invention also uses compositor work.This compositor produces the sound beyond the rhythm and debugs use CV(control voltage) input.Adopt after these, the scope multiplication of current potential effect is because the voltage of input can be programmed to control multiple music parameter.

The circuit of Fig. 5 is mimic channel fully.For wanting the combined digital signal processor, each output no matter be before amplifying or after amplifying, is all made a kind of ADC(analog to digital converter).Microprocessor (or other digital signal processing circuit of knowing) is monitored the gained numeral of pad capacitance variations in a period of time scope according to the pre-programmed rule of logic (software), and sets up the corresponding digital control signal.

According to the MIDI(musical instrument digital interface) or other communication protocols, it also is possible that described system is changed into the output digital controlled signal.This is by an ADC output of each discrete circuit to be handled with the numeral that is created in the variation of following period of time sensor capacitance to finish.A microprocessor or other digital signal processing circuits are monitored these numerals according to the pre-programmed rule of logic, and set up digital controlled signal, additional control device (switch, slidingtype potentiometer, demonstration, or the like) and the hardware and software that is suitable for can combine, can change aforesaid logic pre-programmed rule.Other stipulations also may exchange with robot with computing machine.Being engaged in the technology of this work is known by those skilled person of this technology.

The way of other iteration also may comprise different profiles, different mode configurations, the difform district of knocking of knocking district, different numbers, various and the strict different structure of flat, and various be not with drum rod or drum hammer but optimum is played the modification of (as health eggplant melody) with hand.

Example in another musical instrument field is that " interlayer " discussed above electrode 1-1 '-2-3 can be combined into the guitar pick backplate (guitar pickguard) that has two or three little sensitive area, and these sensitive area can be knocked or thrum to produce the CV signal to control bulging machine or driving MIDI transducer.Electronic installation can be placed in the cavity under the plectrum backplate.

Another iteration way of this product is to allow to use one or more " flowing " pad 1-1 '-2-3, this pad has a suitable retention mechanism and can be placed in the lip-deep selected position of guitar, for example under player's right arm or on hand or other parts of player's health, its use the electronic installation of packing into finish to the plectrum backplate in the quilt similar function of pad of tacking.In addition, electronic installation also can be changed with generation or midi signal or subsequently can be in order to the digital code information of control MIDI music device, guitar effect, stage equipment etc.

The actuating pad of difform actuating pad 1-1 ', different numbers, the pads placement on other parts of guitar and the functional similarity system or the pads placement on other musical instruments of installing as independence also obviously are available.

Conversion absolute pressure or knock make system become more insensitive as need, so that can add a rigid layer on elastomeric pad electrode 1-1 '.Moreover drum-type instrument can play the function of keyboard, and its effect is just like the like that holding signal of being narrated in the said patent by keeping pressure on the top cover, and controls tone or sound by vibration pressure etc.

As mentioned above, the present invention also can be used for other outer purposes of musical instrument, comprise as the diagrammatic representation of pressure variation and model is provided on printout or cathode-ray tube (CRT), be more typically sensor as remote-control gear device (telefactoring) usefulness, the watch-dog of the power of using such as closure valve, or the like, and the contact watch-dog that in other are used, comprises motor vehicle.

Other change also can be made by those person skilled in the art scholars, and these changes are considered to belong to the spirit of the present invention's defined in subsidiary claim and category.

Claims (20)

1, a kind of capacitive pressure-sensing sensor, comprise first electrode assembly and second electrode assembly, first electrode assembly wherein is covered with the semi-rigid overlayer of one deck, and by solid be divided into fragment every the rubber type of material sheet of electrically conductive elastic make, it is characterized in that, the elastic conductive projection that a plurality of tight spacings are arranged on the rubber type of material sheet of this electrically conductive elastic, projection protrudes from a surface of this conductive plastic film, and but pressurized is arranged and the adjacent area that is out of shape, exert pressure by apparent surface and can make its adjacent area compressive deformation at this sheet, and this second electrode assembly spreads out together altogether towards projection and with projection, and with the thin dielectric of one deck second electrode assembly and projection is separated between first and second electrode assemblies.

2,, it is characterized in that wherein a plurality of projections are the closely projections at interval that are placed in two-dimensional array as desired a kind of capacitive sensor in the claim 1.

3, as desired a kind of capacitive sensor in the claim 2, it is characterized in that wherein projection when deformation, exist owing to dress up irremovable second electrode assembly, so aspect pressing, be restricted.

4, as desired a kind of capacitive sensor in the claim 3, it is characterized in that said projection is evenly distributed on the said array basically, when being pressed towards second electrode assembly that dielectric layer is arranged betwixt, projection has deformable curved surface.

5, as desired a kind of capacitive sensor in the claim 1, each electrode assembly that it is characterized in that said sensor all is connected to electronic installation, is changed by the capacitive character that pressure deformation produced of first electrode assembly and produces signal corresponding to same pressure deformation in order to sensing.

6,, it is characterized in that said electronic installation produces signal and knocks caused sensor electrical capacitive variation on the said apparent surface of first electrode assembly with response as desired a kind of capacitive sensor in the claim 5.

7,, it is characterized in that the caused capacitive character of pressure-area-model that said electronic installation produces on signal is applied to first electrode assembly with response the said apparent surface changes as desired a kind of capacitive sensor in the claim 5.

8, as desired a kind of capacitive sensor in the claim 5, it is characterized in that wherein having the conversion of signals that will be produced is the audio representation of pressure deformation.

9,, it is characterized in that audio frequency wherein represents it is to be subjected to similar bulging class to knock and scan the sound and the sound of the drum class that produces on the said apparent surface of first electrode assembly as desired a kind of capacitive sensor in the claim 8.

10,, it is characterized in that pressure wherein is to be added to said apparent surface by dress bulging cap layer thereon as desired a kind of capacitive sensor in the claim 9.

11,, it is characterized in that wherein other analog sensor zone is provided near the sensor of mentioning for the first time, so that produce the independent drum class effect of multi-region as desired a kind of capacitive sensor in the claim 9.

12,, it is characterized in that wherein having the visible device shown that the conversion of signals that will be produced is a pressure deformation as desired a kind of capacitive sensor in the claim 5.

13, as desired a kind of capacitive sensor in the claim 2, it is characterized in that wherein projection be variable thickness as being the projection of taper slightly.

14, as desired a kind of capacitive sensor in the claim 13, the thickness that it is characterized in that said thin slice is 1/10th to 9/10ths inches rank, the projection distribution density is 100 per square inch, and its thickness is one of percentage to 9 percent inches rank, and each about 1 mil of second electrode assembly and dielectric layer.

15,, it is characterized in that said second electrode assembly comprises that the electrode of a plurality of adjacent sections works with the single first public elastic electrode device as desired a kind of capacitive sensor in the claim 1.

16,, it is characterized in that the said first elastic electrode device comprises the elastic electrode of a plurality of separate sections as desired a kind of capacitive sensor in the claim 1.

17,, it is characterized in that this spacer assembly is to be placed between the section elastic electrode as desired a kind of capacitive sensor in the claim 16.

18, the pressure sensing method of a kind of capacitive character, it is characterized in that it comprises: make the adjacent area of electrically conductive elastic plastics two-dimensional array of the projection of tight spacing take place dynamically to change, make each projection because of above-mentioned pressure deformation towards a predetermined direction with by pressure shape corresponding to one or more the regional predetermined pressure model that extends in array; The limit deformation of the outline line of restriction projection is on a fixed position, that spread out jointly, cooperative, capacitive electrode is surperficial, and this surface is separated by a thin dielectric medium and an array; And sensing goes out the dynamic capacity variation that is caused by projection under the pressure shape, with produce mutually should pressure electric signal.

As desired a kind of method in the claim 18, it is characterized in that 19, between deformation phases, this signal is converted into audio tones and sound.

As desired a kind of method in the claim 19, it is characterized in that 20, between deformation phases, this signal is converted into visible demonstration.

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