CN1038342A - Has the capacitive type measurement transducer that improves electrode spread - Google Patents

Abstract

A kind of capacitance-type measuring device comprises first and second electrodes display that is installed on respectively on first and second support components, and support component can produce to each other and relatively move.The first electrode group comprises a series of first discrete electrodes, evenly separate with the spacing Pr that determines scale wavelength between first electrode, the second electrode group comprises a series of second discrete electrodes, and second electrode spread becomes a series of electrode groups of N electrode that respectively are, N is the integer greater than 2.Second electrode that forms each electrode group is placed in corresponding assembly, so that can correspondingly occupy the predetermined group of position that is distributed in greater than the distance of a scale wavelength, like this, the relevant position of the corresponding scale wavelength segmentation position family that each group position is different with is corresponding, the segmentation position is that component is become and the corresponding interval of scale wavelength, each spacing is divided into that the N five equilibrium obtains again.

Description

Has the capacitive type measurement transducer that improves electrode spread

The present invention is the partial continuous application of No. 071030346 co-applications of submission on March 26th, 1987.

The present invention relates to measure the displacement measuring device of dimension and angle, particularly capacitance measuring device.

The capacitance measuring device of many measurement dimensions and angle is improved, in these devices, relative displacement can take place in a series of discrete capacitive coupling electrodes to each other, produces the treated electric signal that interpolation (interpolation) measurement data can be provided thus.The example of these devices comprises that the applicant is in U.S. Patent No. 4420754(' 754 patents) in disclosed existing device and people such as U.S. Patent No. 4586260(Baxter) in disclosed device and U.S. Patent No. 4654524(kita) in disclosed device.

The resolution of various these measurement mechanisms of related factor and precision comprise the size of electrode and the geometry and the precision that aligns of spacing and measuring sensor.Interpolation of data grade and precision as the function of signal noise also are very important.Signal noise comprises the noise that mixes that noise that interelectrode additional coupling causes and electric signal handle.

If increase cost and the complicacy of making indistinctively and introduce non-linear sensitivity or required high-quality signal processing, make that then remarkable improvement of resolution of capacitance measuring device is impossible.For example, aforesaid applicant is in ' 754 patents in the disclosed sensor, and resolution is basically by scale wavelength (promptly to a given signal phase, the distance that the electric capacity function repeats, the spacing of it and scale electrode is corresponding) and the decision of interpolation grade.Scale wavelength is short more, and it is low more to reach the needed interpolation grade of given resolution.Otherwise, for realizing same resolution, increase the interpolation grade, then allow longer scale wavelength.

Yet in applicant ' 754 patents on the disclosed sensor, and the corresponding a plurality of transmitter electrodes of the number of phases that transmits are placed between the scale wavelength, and therefore, transmitter electrode must have the spacing more much smaller than scale electrode.So, the remarkable minimizing of scale wavelength will be subjected to significantly reducing the restriction of the ability of the width of corresponding transmitter electrode and spacing, and needs simple and cheap relatively manufacturing technology (for example printed circuit technique) is changed over complexity and the technology (for example film vapor phase deposition technique) of costliness.Similarly, increase the interpolation precision, need circuit more complicated and expensive, and in portable hand-held measurement mechanism (for example, caliper), adopt under the condition of low-voltage system, increase the interpolation grade and be even more important.

As another example, in people's such as the Baxter that mentions in front the system, transmitter electrode longitudinally is divided into the X group and the Y group electrode of orthogonal space.The quarter-phase high-frequency excitation signal alternately puts on the element of transmitter electrode respectively, has produced X and Y pickoff signals, and this expression is capacitively coupled to signal on the receiver electrode that faces mutually with the Y group from the corresponding X of sliding members.Yet the arranged in groups of transmitter electrode makes between people's such as Baxter system's vernier (slider) and the scale heterogeneity at interval responsive especially.

As another example, in the aforesaid Kita system, two displays that adopt n and n+m element to form respectively produce one group of output, when mapping with respect to the continuous position of one group of display element, output level forms ripple, and output phase changes with the relative displacement of two groups of displays.Measure this displacement by measuring the phase change of composing with respect to the maximum possible value of element output.Yet this measuring technique need be carried out statistical treatment to each output, so that obtain the most probable position of each output, this need carry out a large amount of computings to the system that many group display elements are arranged.

A basic purpose of the present invention provides a kind of improved capacitance measuring device structure, and it allows to utilize given manufacturing technology to obtain short scale wavelength.

Another object of the present invention provides a kind of improved capacitance measuring device structure, wherein can realize given scale wavelength simpler and cheaply, finish and measure required signal Processing amount or complicacy and needn't increase gap changing sensitivity or increase.

These and other objects of the present invention can be realized by a capacitance measuring device.First and second capacitive coupling measurements display that this device comprises on first and second support components that are placed in relative displacement respectively and aligns with measurement axis is so that obtain a capacitive characteristics curve that changes with the relative position between support component.First measures display comprises that with the Pr that is defined as scale wavelength be spacing and the first a series of discrete electrode that evenly separates, second measures display comprises a series of second discrete electrodes, second electrode is so settled, so that can carry out capacitive coupling according to the relative position of support component and the different piece of the first measurement group.Many electrode groups that respectively have N electrode have been determined in the arrangement of second electrode, and wherein, N is one greater than 2 integer, and, ⅰ wherein) to have identical group be the multiple of scale wavelength apart from Pg.Pg to each electrode group; ⅱ) second electrode that forms each electrode group is so arranged in corresponding group, so that it occupies predetermined group of position greater than a scale wavelength distance respectively, the diverse location in the gang corresponding scale wavelength segmentation position is represented in each position, these segmentation positions are that electrode group distance is divided into and the corresponding interval of scale wavelength, each are divided at interval that section such as N part obtains again.The group electrode preferably is distributed in the whole class range, makes each of this group have one second electrode at least at interval.

According to a further aspect in the invention, second electrode evenly separates with spacing Pt, and group is the integral multiple of scale wavelength apart from Pg, and the electrode in every group occupies the same position order of respective sets position.On the other hand, second electrode separation is inhomogeneous, and the electrode in every group is divided into two groupings at least.Second electrode in each grouping evenly separates with first spacing, and separates with second spacing different with first spacing between the grouping.The non-homogeneous second electrode group that separates is determined a group family at least, and family is the integral multiple of scale wavelength apart from Ps, and the respective sets position that second electrode in the gang in each electrode group occupies is different.Therefore, electrode of one group of interior each grouping occupies different corresponding scale wavelength segmentation positional alignment (Permutation).

In accordance with a further aspect of the present invention, the corresponding scale wavelength sequence of positions that the signal that the different cycles that N increases progressively changes occupies by second electrode in each group puts in this group on corresponding second electrode, the output of being coupled to first electrode on second electrode converges into a composite signal, can obtain displacement data from this signal.

As a result of the present invention, adopt second electrode with spacing bigger than scale wavelength, might obtain identical resolution.This perhaps obtains a given scale wavelength in simpler mode with regard to allowing or obtaining short scale wavelength with given manufacturing technology, and needn't increase non-linear sensitivity or need additional or more complicated signal Processing.

These and other characteristic of the present invention and characteristics will obtain by the following detailed description to most preferred embodiment describing or understanding.

Most preferred embodiment provides description with reference to the accompanying drawings, and wherein, components identical is represented with identical reference number.

Fig. 1 is the perspective diagram with capacitor type caliper of a sensor that constitutes according to the present invention.

Fig. 2 is a conventional capacitance type sensor electrode spread and the comparison diagram arranged according to sensor electrode of the present invention.

Fig. 3-the 7th is according to the synoptic diagram of various electrode spread of the present invention.

Fig. 8 is the type signal generation of employing sensor of the present invention and the functional-block diagram for the treatment of apparatus.

Fig. 9 is the waveform sequential chart of the various signals of device generation shown in Figure 8.

With reference to Fig. 1, the linear caliper 10 of the capacitor type that constitutes according to the present invention is made of sensor 12 and sensitive element 40 basically, sensor 12 comprises the first linear support element 20 and the second linear support element 30, the second linear support element 30 is slidably mounted on the support component 20, so that produce length travel along measurement axis X with respect to element 20.For simplicity, support component 20 and 30 preferably is equipped with the caliper arm (not shown) of elongation, so that object is carried out linearity measure.Gap between the support component 20 and 30 is the magnitude of 0.05mm (0.002 inch) preferably.

Align toward each other and with corresponding measurement axis and gage beam and to be placed in displaying by first electrodes displays and second electrodes of 22 and 32 expressions respectively on the corresponding support component.Electrode display 22 is fitted on the support component 20, it comprises the discrete receiver electrode 24 that is electrically insulated from each other of the row of one shown in the figure, these receiver electrodes have identical geometry, and according to predetermined required scale wavelength, separate each other between the spacing Pr(respective edges distance identical) along measurement axis.The electrode display 32 that is disposed on the support component 30 comprises the discrete transmitter electrode 34 of a row, and these transmitter electrodes are so arranged, and makes it to carry out capacitive coupling according to the relative position of support component 20 and 30 and the different piece of electrode display 22.Electrode 34 is so arranged with respect to electrode 24 in a predefined manner, and is so that determine a monodrome capacitance characteristic curve that changes with the relative position of support component, such just as will be explained further below.

The exploring electrode layout also is placed on the corresponding support component, and it allows to carry out capacitive coupling between with the first and second detected displays 22 and 32.As shown in the figure, the exploring electrode layout comprise one with support component 20 on the transmission electrode 26 that links to each other of each receiver electrode 24 and one be positioned on the support component 30 34 that face mutually with electrode, relative detector electrodes 36 with transmission electrode 26, so that its specific transmission electrode 26 that links to each other with specific position with electrode display 22 carries out capacitive coupling, and then display 32 with electrode and carry out capacitive coupling.As shown in the figure, transmission electrode 26 preferably is arranged on the same straight line with the electrode 24 that is connected, and is electrically connected with it by the contact electrode 28 that forms on the whole.

Because electrode 24 and 34 signals that produce have the relation of sinusoidal intensity and electrode width (along direction of measurement) in fact, so electrode 24 and the 34 width W x at direction of measurement preferably are chosen for about half of receiver Ke Zhu Jia r.If desired, width W x can be less than half pitch Pr, so that adapt with the sensitivity of the electronic circuit that is used to realize signal Processing.As shown in the figure, the size of transmission electrode 26 preferably makes it to have maximum surface area with respect to detector electrodes, so that maximum signal transmission is provided between electrode 26 and 36.The width that detector electrodes 36 has a direction of measurement is very important, so just can make through by transmitter electrode 34, capacitive coupling receiver electrode 24, transmission electrode 26 come down to identical with the signal transmission of the whole emission path that detector electrodes 36 is determined.Therefore, as shown in the figure, detector electrodes 36 fully extends on two measurement axis directions, to exceed the series of transmitter electrode 34, for example, extension is greater than the distance of a Pr, and like this, any electric field of being sensed the receiver electrode by transmitter electrode all is impaired to negligible degree in the respective end of detector electrodes 36.On the other hand, detector electrodes 36 should display 32 much shorters than electrode, and like this, the electrode field of electrode 36 ends is uniformly, can be avoided by the edge effect that the end of electrode display 32 causes.In addition, when detector electrodes 36 than electrode display 32 in short-term, the effective length of detector 36 must be the integral multiple (Pg will define below) of transmitter electrode group spacing Pg.

If desired, electrode can be displayed 22 and be placed in movably on the support component 30, electrode display 32 is placed on the support component 20, thereby replace mounting means shown in Figure 1.

Sensitive element 40 comes first electrode display of detecting sensor 12 and the capacitive coupling between second electrode display 22 and 32 by the phase relation of measuring between input signal and the output signal, and with the displacement on the direction of measurement relevant between two support components 20 of above-mentioned relation information translation one-tenth indication and 30.According to the present invention, N be one greater than 2 integer, the signal of N the different cycles variation that is produced by signal generator 50 is according to below the predefined procedure that is described in detail being applied on the corresponding transmitter electrode group.The output signal as a result that produces by detector electrodes 36 signal processor 60 of feeding, at this, these signals compare with reference signal in a usual manner, thus the measurement data of obtaining.As below will being described in detail, signal generator 50 is polyphase signa generators, and it can produce N the periodic signal with same magnitude and frequency, but phase place increases the 360/N degree each other.The final phase shift that signal processor 60 is measured the sensor output signal that is obtained by exploring electrode 36.

See the setting of transmitter electrode 34 again, the width of the direction of measurement of discrete transmitter electrode can make it enlarge markedly with respect to scale wavelength by arranging these electrodes, promptly, determine a series of electrode groups, each electrode group has N electrode 34 and identical group spacing Pg(Pg and is defined as distance between the termination electrode edge of adjacent set), Pg be scale wavelength multiple doubly.In each electrode group, the electrode 34 corresponding positions that occupy the N group, these positions greater than the range distribution of a scale wavelength to be separated by.Each position is corresponding to the different relevant positions of respective wavelength segmentation position family, and these segmentation positions are that an electrode group distance is divided into and the corresponding interval of scale wavelength, and each is divided at interval the N equal portions obtain.The group distribution of electrodes is organized on the whole direction of measurement width in this, thereby makes to have an electrode 34 at least on each interval of this group.

In order to help to understand this aspect of the present invention, figure 2 illustrates and be used for the aforementioned application people in the disclosed conventional sensors of ' 754 patents be used for the overlapping relation that sensor respective electrode of the present invention is arranged, these two sensors all have signal generators 50 that produce 8 different output signal orders that increase progressively.As shown in the figure, the transmitter electrode 34a of conventional sensors equals 1/8 scale wavelength (receiver electrode separation Pr) with the spacing Pt of corresponding receiver electrode 24.8 output signals that signal generator 50 produces are connected with transmitter electrode 34a with the ordered series of numbers (1-2-3-4-5-6-7-8) of repeated incremental respectively, as shown in the figure, so just determined the many identical group 35a of electrode 34a, these electrodes link to each other with the different output signals of sequential signal generator respectively.The electrode 34a of each group 35a is distributed in the corresponding distance of signal scale wavelength last, (the signal scale wavelength is receiver electrode separation Pr).

In contrast, according to the spacing Pt=5/8Pr between transmitter electrode 34b of the present invention and the corresponding receiver electrode 24, so Pg equals 5 scale wavelengths (Pg=5Pr) between final group of the group 35b of 8 transmitter electrode 34b.Furtherly, component is being become 5 scale wavelengths intervals and each scale wavelength is being divided at interval on the basis of 8 segmentations, as can be seen, for each electrode group 35b, transmitter electrode 34b occupies the such position in this group, so that dispose a transmitter electrode 34b at each scale wavelength of this group at least at interval, every group of electrode position is corresponding with the relevant position of different scale wavelength segmentation.Adopt an ordinal number ordered series of numbers to discern corresponding scale wavelength segmentation position.In scale element 20 and 30 transmitter electrode 34b in fact with above-mentioned applicant ' 754 patents in the configuration of disclosed conventional transmitter electrode be identical.Unique remarkable difference is, for obtain with the applicant ' 754 patent working examples in identical capacitance characteristic, the receiver electrode signal must be in the scope integrates of a plurality of scale wavelengths.Yet the present invention allows to adopt much wide emitting electrode spacing and obtains identical result, thus also allow to adopt than scale wavelength wide the transmitter electrode of Duoing.

To be understood that, the N that fixes a number that supplies for a signal generator output signal, have n transmitter electrode spacing, these spacings allow N electrode to be uniformly distributed on the interior foregoing different corresponding scale wavelength segmentation position of a plurality of scale wavelength scopes.Fig. 3 illustrates in the arrangement that another so little T of Ke  handkerchief instructs in the measuring system of N=8, transmitter electrode spacing Pt=3/8Pr, and the respective transmitter electrode 34 in every group has order and is the corresponding scale wavelength segmentation position of 1-4-7-2-5-8-3-6.Other possible arrangement comprises Pt=7/8Pr, arranges for described later these, and the order of corresponding scale wavelength position is respectively 1-8-7-6-5-4-3-2 and 1-2-3-4-5-6-7-8.

Though transmitter electrode 34 preferably has same spacing Pt, group spacing Pg is the integral multiple of scale wavelength, every group electrode occupies the corresponding scale wavelength segmentation position of organizing same order with other, but in the foregoing embodiments, does not need transmitter electrode to have identical position.Fig. 4 illustrates the electrode spread of a N=6, wherein, the transmitter electrode in every group is arranged in two groupings.As shown in the figure, group spacing Pg=3Pr presses the first spacing Pt each other between the electrode in each grouping ₁=2/6Pr evenly separates, between the grouping greater than the first spacing Pt ₁The second spacing Pt ₂Evenly separate (Pt ₂=9/6Pr).The arrangement of electrode 34 still can be so that have an electrode at least in every group of embodiment shown in Figure 4 in each scale wavelength interval of this group, every group of position constitutes different corresponding scale wavelength segmentation positions, and electrode is similar with the foregoing description that identical spacing separates in each group of this and its.

Have, among the embodiment shown in Fig. 5-7, have the non-homogeneous transmitter electrode that separates, these electrodes are preferably so arranged, so that its at least one electrode group family has the family of the integral multiple that equals scale wavelength apart from Ps.As shown in the figure, the transmitter electrode 34 residing corresponding scale wavelength segmentation sequence of positions in family in the grouping of each electrode group and each group are different, thereby make all signal phases in this family have identical transport property.With reference to Fig. 5, Fig. 5 illustrates first selectable arrangement of N=6, and the electrode group has determined to comprise three groups, and the family of the spacing Ps=7Pr of family is arranged.Every group comprises two groupings that three electrodes are arranged, shown in the embodiment of Fig. 4.The same with the electrode among the embodiment of Fig. 4, the identical spacing Pt that separates each other of the electrode in each grouping ₁=2/6Pr, but between grouping, have less spacing Pt ₂=7/6Pr, group spacing Pg=14/6Pr.As shown in the figure, in whole family, the order of the corresponding scale wavelength segmentation position of each grouping is different, and these orders are respectively: 1-3-5,2-4-6,3-5-1,4-6-2,5-1-3,6-2-4.Therefore, the phase place of all signals in the distance that whole group of family covers is identical, and all signal phases have experienced the one group of identical electric capacity edge effect and the condition of adjacent electrode capacitance, thereby have reduced interpolated error.

The embodiment of Fig. 6 is similar with Fig. 5, and different is: Ps=13Pr, Pg=26/6Pr, Pt ₁=4/6Pr and Pt ₂=13/6Pr.In the embodiment of Fig. 7, every group comprises the grouping that two electrodes are arranged.In each grouping, the spacing of electrode is Pr ₁=13/6Pr, grouping spacing Pt ₂=7/6Pr, group spacing Pg=21/6Pr.These electrode groups have been determined a family that has two groups, and family's spacing is Ps=7Pr.

Be to be to be subjected to required precision and the influence of the complexity of the responsive instrument that obtains with what be further appreciated in order to obtain selection number N in the separation signal that adopts with the corresponding transmitter electrode of capacitive coupling relation configuration and the capacitive transmission function between the receiver electrode.Interpolated error increases with the N value and reduces.Yet the N value is big more, and required signal generation and treatment circuit are expensive more, and the connection a few days required between sensor and the signal generating circuit is many more, has increased source of error.

In Fig. 8 and Fig. 9, the electrode that uses description to detecting sensor 10 displays an exemplary embodiments of the sensitive element 40 of the coupling capacitance between 22 and 32.

Signal generator 50 comprises that being used to produce frequency is f ₀The device 52 that shakes of continuous HF square-wave (HF) signal 100, be used for the output signal 100 of oscillator is divided into the frequency divider 54 of three corresponding low frequency signals 150, be used for signal 130 is converted to the phase converter 56 of 8 control signal 200-1 to 200-8, (these control signals that recur have identical pulse width and repetition rate and 45 ° of mutual phase shifts), with the modulator 58 that is used to modulate the oscillator output signal 100 that has 8 signal 200-1 to 200-8, so that generation 8 phase shift pumping signal 202-1 to 202-8 as shown in Figure 9.To be understood that best anti-phase (the 180 ° of phase shifts) signal by response impulse signal 200 of the modulation of output signal 100 is finished, this makes that each pumping signal 202 all is that frequency is f ₀Continuous output signal, but these signals have relative anti-phase part according to the pulse signal 200 that is attached thereto.Modulator 58 comprise a series of different one or the door, each have one with a signal input end that links to each other and other input end that links to each other with high-frequency signal 100 in the signal 200, when signal 200 was high level for a door, the signal 202 of this output was non-inversion signal 100.When signal 200 was low level for a door, the signal of this output was non-inversion signal 100.The bag route of signal 200 for clarity sake, only is shown.Exciting signal 202-1 to 202-8 is connected on 34 groups of the transmitter electrodes of sensor 12 in a manner described successively.

Signal processor 60 comprises: the amplifier 62 that is used to amplify the synthetic high frequency modulated square-wave signal output that the detector electrodes 36 by sensor 12 produces, synchronous demodulator 64 by output 100 control of oscillator 52, (it is used for the amplification sensor signal 204 that demodulator amplifier 62 produces, so that form synthetic square wave bag route output signal 206 as shown in the figure), be used for eliminating the harmonic wave of demodulated output signal 206, the wave filter 66 that makes it only to keep basis and therefore produce the signal 208 that is essentially sine as shown in the figure, be used for when signal 208 is more zero in a predetermined direction, producing the more zero detector of a control signal 210, the counter 70 of record oscillator output signal 100, (this counter be the reference control signal 300 that produces with control module 80 that the startup of counter/input that resets links to each other with the control of the control signal 210 that stops to import more zero detector 68 generations that link to each other of counter under count), be used for the counting of counter 70 output 212 is converted into the display 74 of the output of the data processor 72 of digital variable quantity and display data processor 90.The reference control signal 300 that produces by control module 80 be with control signal corresponding 200 in the generation of a signal (for example 200-1) produce synchronously, and the control signal 150 that produces with frequency divider 54 is corresponding.The work of data processor 72 is in a usual manner, controls by another control signal 400, and the control signal 400 that is produced by control module 80 is synchronous with the generation in whole cycle of control signal 200-1 to 200-8.

As known to those of ordinary skills, the output of sensor 12 (output signal 206) in form to the applicant ' 754 patents in disclosed sensor output similar, it has reflected that the capacitive characteristics on direction of measurement distributes.This distribution is meant by transmitter electrode 34, the distribution on receiver electrode 24, connection electrode 28, transmission electrode 26 and the control electrode 36 determined signal paths.Yet the output of sensor 12 is the average signals that obtain in a plurality of scale wavelength scopes, rather than in the length of a scale wavelength, obtain.Filtered sensor output signal with respect to the phase shift theta of the sequential of the input signal that produces output signal still with the interelement relative displacement of sensor support linear (in the displacement range of a scale wavelength), be θ=dx/Pr(360 °), dx is a measuring distance.Can clearly be seen that as mentioned above, and the time between the counting that the counting of the counter 70 that the generation of a signal in the signal 200 occurs simultaneously opens beginning and the counter that occurs simultaneously of 5 sensor output signals of having handled 208 0 stops, having reflected measured phase shift.And convert the data of reflected measurement easy as can to apart from dx.

Because the output of sensor 12 and applicant ' output of the sensor of 754 patent disclosures has identical form, be shown in ' accompanying drawing 9 of 754 patents and the signal processing circuit of the harmonic wave that is used for the output of filtering sensor that is modified among the accompanying drawing 14-16 preferably be used in signal generator 50 and the signal processor 60.Applicant's disclosed foregoing circuit electricity in ' 754 patents is introduced among the application as a reference.

Above-mentioned continuous signal treatment circuit can selecteed another kind of circuit, it adopted by the choosing of signal 202 to and two variability integrations (dual-yamp integyation) of the output that produces, sort circuit is disclosed in the applicant and is called the co-applications of " capacitance-type measuring device that is used for the position absolute measurement " in the name of applying for simultaneously with the application, this co-applications is also introduced thus, as a reference.

Above-mentioned most preferred embodiment has only been done exemplary explanation to the present invention, can carry out multiple improvement in principle of the present invention and scope.Particularly, though the present invention has described the implementation method aspect the linear caliper of portable hand-held, but for the person of ordinary skill of the art, the present invention is not limited to these measurement mechanisms, but go for the measurement of various dimensions or angle, comprise large-scale surveying instrument, as three-dimensional coordinate measuring system and numerical control finishing machine.

Claims (10)

1, capacitance-type measuring device comprises:

First and second support components, described support component can relatively move each other, and at least one described support component can move with respect to measurement axis;

Be installed on first and second electrodes display on described first and second support components respectively, they and described measurement axis align, and change the capacitance characteristic curve that produces so that obtain by the relative position between described support component;

Described first electrode display comprises a series of first discrete electrodes, and these electrodes evenly separate with the spacing pr that determines scale wavelength;

Described second electrode display comprises a series of second discrete electrodes, and these electrodes so dispose, and enables to carry out capacitive coupling according to the relative position of described support component and the different piece electric capacity of described first electrode display; With

Described second electrode is so arranged, so that determine a series of measuring sensor groups that separate with group spacing pg, wherein each electrode group has N measuring sensor, N is the integer greater than 2, second electrode that forms each described electrode group is placed in the respective sets, make it to occupy the predetermined group of position that is distributed in greater than a scale wavelength distance, the relevant position of the corresponding scale wavelength segmentation group that each position is different with is corresponding, the scale wavelength segmentation is that the group spacing is divided into and the corresponding spacing of scale wavelength, again each is divided into the N equal portions at interval and obtains;

Signal generator unit; it comprises that with at least one the composite signal of N excitation cycle signal puts on second electrode of described each electrode group, thus make described pumping signal can be correspondingly according to chirp  pool, the Ke  season common bluebeard south extensive alliance of alkynes ǔ nephew Laos in every group hold larva of a tapeworm or the cercaria of a schistosome ┘ help the humorous  Ke of the hole big shield apricot Yun of Venezuelan south assorted Φ capsule Huan bucktooth Ke uncommon slow

Detector assembly, it comprises when detection responds with described at least one synthetic pumping signal, first electrode capacitance is coupled to the detector electrode device of the output signal of described second electrode display generation, so that obtain the output signal of the first electrode output signal total value of a reflection detection; With

Signal processing apparatus, it is used for obtaining measurement data from described detector electrode device output signal.

2, measurement mechanism as claimed in claim 1, wherein said signal generator unit comprise the device that is used to produce N continuous different pumping signal.

3, measurement mechanism as claimed in claim 1, wherein, described signal generator unit comprises the device of the composite signal that is used to produce N continuous different described pumping signal.

4, measurement mechanism as claimed in claim 1, wherein, described second electrode evenly separates with spacing Pt, and described group of spacing Pg is the integral multiple of scale wavelength; And there is one second electrode at least in each group interval.

5, measurement mechanism as claimed in claim 1, wherein, second electrode in each described second electrode group is divided into two groupings at least, and second electrode in each described grouping evenly separates with first spacing, and described grouping evenly separates with second spacing that is different from first spacing.

6, measurement mechanism as claimed in claim 5, wherein, many described second electrodes are permitted to determine the group family with the spacing Ps of family, spacing Ps is the integral multiple of scale wavelength, for each grouping that should organize in each group in the gang and this family, the corresponding scale wavelength segmentation sequence of positions that second electrode occupies is different.

7, measurement mechanism as claimed in claim 1, wherein, described signal generator unit produces the signal that the 360/N degree is passed in the individual phase shift to each other of N continuously.

8, measurement mechanism as claimed in claim 5, wherein, described signal processing apparatus comprises the harmonic wave that is used for the described detector electrode device output signal of filtering, so that obtain being essentially the device of sinusoidal measurement signal, measure the phase place of described measuring-signal with being used to, so that obtain the device of measurement data with respect to one of described pumping signal.

9, capacitance-type measuring device comprises:

First and second support components, described support component can relatively move to each other, and at least one described support component can move by the relative measurement axle;

Be installed on first and second electrodes display on described first and second support components respectively, they and described measurement axis align, so that obtain the capacitance characteristic curve according to the variation of the relative position between described support component.

Described first electrode display comprises a series of first discrete electrodes, and these electrodes evenly separate with the spacing Pr that determines a scale wavelength;

Described second electrode display comprises a series of second discrete electrodes, and these electrodes so dispose, and enable to carry out capacitive coupling according to the relative position of described support component and the different piece of the described first electrode group; With

Described second electrode is so arranged, so that determine many measuring sensor groups that separate with group interval Pg, wherein each electrode group has N measuring sensor, N is the integer greater than 2, second electrode that forms each described electrode group is placed in the respective sets, make it correspondingly to occupy the predetermined group of position that is distributed in greater than the distance of a scale wavelength, each position is corresponding with the relevant position of different corresponding scale wavelength segmentation group, the scale wavelength segmentation is that a group spacing is divided into and the corresponding interval of scale wavelength, each spacing is divided into that the N equal portions obtain again; With

Second electrode of each described second electrode group further is divided at least two groupings, and second electrode in each described grouping separates with first spacing, and described grouping evenly separates with second spacing that is different from described first spacing.

10, measurement mechanism as claimed in claim 9, wherein, many described second electrode groups determine that has the group family that family's spacing is Ps, spacing Ps is the integral multiple of scale wavelength, among each grouping that should organize in each group in gang and this family, the corresponding scale wavelength segmentation sequence of positions that second electrode occupies is different.

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