JPH0335119A - Capacity type position measuring instrument for absolute measurement - Google Patents

Abstract

PURPOSE:To take an absolute measurement over a wide measurement range by including a 1st linear scale or support member for the formation of am measurement axis in a converter and a 2nd linear scale or support member which is positioned slidably on the long axis of the support member. CONSTITUTION:Calipers include basically the capacity type converter 12 and an electronic measuring instrument 100 which generates an electric excitation signal and processes the output signal of the converter 12 so as to confirm a given measurement point. Further, the converter 12 includes the 1st linear scale or support member 20 for the formation of the measurement axis X and the 2nd linear scale or support member 30 which is positioned slidably on the long axis of the member 20. Further, seven electrodes defined by symbols 210A and 210B, 220A and 220B, 310, and 320A and 320B are arranged on the member 20 opposite each other corresponding to the calipers arms. Then an electrode array 310 on the member 30 consists of solid bodies of 1st transmitting electrodes 312 arranged on the opposite side from the electrode arrays 210A and 210B and are coupled with the electrode arrays 210A and 210B by the relation of the members 20 and 30.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention generally relates to a capacitive measuring device that performs linear and nonlinear measurements, and more specifically to a capacitive foot transformer with an improved arrangement of electrodes for absolute measurement. This relates to a deuser.

BACKGROUND OF THE INVENTION A number of capacitive measuring devices have been developed for making linear and curved measurements, in which individual electrode rows are located on two opposing supports or scales and are capacitively connected to the electrodes.
Some determine the relative position of two scales by sensing the results of changes in capacitance patterns caused by electrode arrays.

Typically, the capacitive pattern is sensed by generating a periodic signal on one of the electrode columns and measuring movement as a result of the converted signal from the other electrode column. Such measuring devices are used in three-dimensional coordinate measuring systems, ranging from large-capacity devices such as numerically controlled final devices to small instruments such as small calipers and micrometers.

Although capacitance-measuring devices have become popular, they have had drawbacks such as a limited measurement range. The main reason for the shortcomings is the fact that conventional capacitive measuring devices allow relative but not absolute measurements. That is, measurements have been made by sensing relative changes in the position of the scale with respect to a reference point, which requires continuous sensing of changes in the capacitance pattern caused by the electrode array so that pattern repetition can be calculated.

Additionally, relative measurements required setting of a new reference point or zero point before each measurement, which was cumbersome in conventional equipment.

In addition, if the scale ratios of relative devices that can be replaced relative to each other are replaced too quickly, a total of 7111 errors will occur. On the other hand, increasing the allowable scale replacement speed requires high frequency signals and high precision signal processing circuitry which leads to a substantial increase in the cost of the measurement equipment.

The advantage of absolute measurement of the scale position, i.e. of measuring only the final measurement point of the scale, is that it eliminates the various problems mentioned above. What is the 0 or reference setting for the scale? ! -1 between the fixed device assemblies and does not require adjustment of settings during successive measurements. The capacitance pattern of the scale electrodes only needs to sense the final measured position of the scale, and the displacement rate of the scale is not limited in any way. Furthermore, when the final measurement position is measured, the power source only needs to be continuous and depleted.
! ! The number of electrodes is significantly reduced, allowing the use of small-capacity power sources such as solar cells.

The inventor is US Patent No. 4,420,754 ('7
10.11 of Patent No. 54), he had previously invented a capacitive measuring device capable of absolute measurement, as shown in FIG. The device employs side-by-side separated first and second pairs of transmitting/receiving electrode arrays. The pitch relationship of the transmitting electrodes to the receiving electrodes is the same for each electrode pair, and the corresponding transmitting/receiving electrode pitches are slightly different between the two pairs of two rows. 2
Two separate n-phase signals are transmitted to two corresponding row pairs of transmitting electrodes, and two independent signals vl and v2 are obtained (through associated transducing and sensing electrodes) from corresponding receiving electrodes between each row. The absolute measurement value is derived by determining the phase difference between the two signals vl and v2 by /l1ll.

[Problems to be Solved by the Invention] However, the measuring device of the -754 patent has limitations in convenience. For example, the calculation of absolute measurements is based on two independent measurements, and the accumulation of small errors leads to large position measurement errors. Therefore, each signal processing circuit should preferably have a characteristic performance to obtain accurate absolute position measurements. Furthermore, if the two measurements are not taken exactly at the same time, even very slowly displacing opposing support members, the two measurements will result in a large error in the position determination.

In addition, the physical requirements for two sets of separate electrode arrays in the measurement device of the '754 patent dictate that the shape of the application be reduced in order to make it a handy measurement device. Furthermore, due to the limitation of the portable measuring device of the same application, the power consumption increases due to the redundant signal processing circuits.

[Means and operations for solving the problem] This drawback of the conventional example is that the first and second support members can be replaced alternately, and at least one of them can be replaced with respect to the support shaft,
a first transmitting electrode array is arranged on the support member along the measurement axis;
A first receiving electrode array is disposed on the second supporting member along the measurement axis, different portions of the first receiving electrode array are capacitively coupled to the first transmitting electrode array depending on the relative positions of the supporting member; 2
A transmitting electrode is disposed on the second support member along the first receiving electrode, and each electrode of the second transmitting electrode is connected to a corresponding one of the first receiving electrodes.
The angle '?' is measured by the measuring device of the invention, which is coupled eccentrically from the corresponding first receiving electrode by a value according to a predetermined function based on the position of the second transmitting electrode with respect to a reference point on the measuring axis. Be erased. The measuring device comprises a second receiving electrode arrangement arranged on the first support element along the first transmitting electrode for sensing the excursion of the electrode.

In a further aspect of the invention, the spatial range occupied by the second transmitting electrode is defined as a first measuring range that exceeds a predetermined amount of electrode deflection angle between the second transmitting electrode and the first transmitting electrode, and the measuring device a third transmitting electrode disposed on the second support member along one receiving electrode, each group of at least one receiving electrode being coupled to a corresponding one group of at least third transmitting electrodes; Each electrode of the third transmitting electrodes in a group of electrodes is electrically connected to one of the corresponding first receiving electrodes such that it is eccentric from the corresponding first receiving electrode by at least a predetermined function value relative to the center of the group of third transmitting electrodes. is connected to. As a result, the deflection angle of the electrodes varies over the at least one third transmitting electrode by the above-mentioned predetermined function value, such that in the spatial range occupied by the at least one third electrode group, the second measurement range is smaller than the first measurement range. Defined as range. Furthermore, the measuring device is arranged on the first support element along the first transmitting electrode row to sense the deviation between the third transmitting electrode and the corresponding first transmitting electrode in the at least one third transmitting electrode group. It also includes a third receiving electrode device.

A further aspect of the present application provides that the first receiving electrodes are spaced apart with respect to the measurement axis by a pitch Prl defined by a close wavelength WA, and the at least one group of the first transmitting electrodes is N adjacent electrodes, where N is an integer greater than two. At least one of the first transmitting electrode groups is defined by a first transmitting wavelength Wt, the first transmitting electrodes of each group being respectively positioned to occupy a predetermined group position over a distance greater than a close wavelength Wf; As a result, each group position corresponds to a different position of the corresponding group of close wavelength division positions obtained by dividing the transmission wavelength Wt into intervals corresponding to close wavelengths and dividing each interval into N equal parts. Furthermore, the measuring device includes a first stage connection in which the first transmitting electrodes in each first transmitting electrode group are arranged in consecutive positions with respect to each other, and a second stage connection in which the first transmitting electrodes are respectively arranged in successive closely spaced wavelength division positions. selectively apply N to the opposing electrodes of each first transmitting electrode group by
An excitation signal device is provided for transmitting the same periodic variable excitation signal.

According to another aspect of the invention, the second and third receiving electrode devices selectively output first and second outputs, respectively, in response to an excitation signal transmitted to the first transmitting electrode array. The measuring device includes a signal for selectively merging the respective first and second outputs to produce a measuring signal that is equal to the signal generated when the second and third receiving electrode devices are extended and have a constant planar shape. It has a processing device.

EXAMPLES These features and advantages of the present invention will become clearer from the detailed description of the examples below.

#A) The present invention relates to a portable hand-held linear measurement caliper. However, the present invention is not limited to the above-mentioned measuring device, but can be used in a wide range of large-scale and small-scale mounting devices for both linear and positive types by those skilled in the art.

1 and 2 show an absolute measurement type capacitive measuring device according to the present invention, which is capable of performing coarse measurement, medium measurement, and close measurement at measurement points using the absolute measurement method.

This device enables highly accurate absolute measurements over a wide measurement range. The caliper 10 basically includes a capacitive transducer 12 and an electronic measuring device 100 for emitting an electrical excitation signal and processing the output signal produced by the transducer 12 to ascertain a given measurement point. Transducer 12 includes a linear first scale or support member 20 and a linear second scale or support member 30 slidably positioned on the long sleeve of indicator member 20 to define measurement axis X. As in the prior art, the support member 20.30 has a caliper arm (not shown) extending for planar measurement of the II constant object. The gap between the supporting members 20 and 30 is 0.
It is about 0.05 open (0,002 inches).

Symbols 210A and 210 are provided on the support member in a manner facing each other corresponding to the caliper arms of all the upper shafts.
B, 22OA, 220B, 310.32OA and 320B
Seven electrodes defined by are arranged.

The details are described below. Predetermined continuous times electrode 31
A plurality of variable periodic signals are transmitted at 0, and a composite signal generated by the difference in electrode structure between the electrode arrays 320A and 320B is sensed depending on the type of measurement (coarse, medium, close). Therefore, to simplify the explanation, the electrode row 310 will be described as the first transmitting electrode, the electrode rows 21OA and 210B will be referred to as the first receiving electrode, and the electrode rows 220A and 220B will be referred to as the second and third receiving electrodes, respectively. The transmission of signals from electrode row 310 to electrode rows 320A and 320B corresponds to the function of each electrode row.

First receiving electrode rows 210A, 2 located on the support member 20
The electrodes 10B having the same shape are sandwiched together to form two rows of electrically isolated first receiving electrodes 212A and 212B having the same homogeneous geometric shape and sandwiched between each other as shown in the figure. The electrodes 212A are spaced apart from each other, and the electrodes 212A are spaced apart from each other.
2B are similarly spaced from each other. Both are arranged in parallel along the measurement axis with a uniform pitch Prl (from corresponding end to corresponding end between adjacent electrodes) equal to the desired first receiving electrode wavelength 1rl (scale or close eye wavelength Vf).

The first transmitting electrode row 310 arranged on the support member 30 includes first transmitting electrodes 31 arranged on the opposite side of the electrode rows 210A and 210B.
The electrode arrays 210A and 210B are connected to each other by the relative positions of the supporting members 20, 30.

The relative spacing between corresponding electrodes of electrode array 310 and 210A/210B is based on several conditions. The coarse measurement of the present invention is determined by transmitting a periodically variable excitation signal N times in succession to a group of N first transmitting electrodes. Here, N is a number greater than or equal to 3, and the signal causes the first
An electric field with a predetermined variable voltage distribution is created across the transmission wavelength 111 corresponding to the pitch Pg of the transmission electrode groups (defined as the end-to-end distance between lead electrodes of adjacent groups). The first receiving electrode rows 21OA/210B are the first receiving electrode rows 21OA/210B whose corresponding first transmitting electrode rows 310 extend over the transmission wavelength Vtt.
The first receiving electrode 21 must have sufficient electrode density to generate a transmitting electric field, and is connected to the first transmitting electrode row 310.
In the portion exceeding the voltage distribution of OA/210B, the voltage distribution exceeds the first transmitting electrode row which is substantially equal. Therefore,
The electrode distribution density of the first receiving electrode row 21OA/210B must be such that at least three electrodes 212A/212B span a distance corresponding to the transmission wavelength Wtt. The pitch Ptl of the first transmitting electrode 312 is set to a desired wavelength for close eyes w.
This is determined in part by the desire that r and at least the first three receiving electrodes 212A/212B be located within the transmitting wavelength Wtt.

In addition, in order to perform close eye measurement using the same electrode array and signal processing circuit, the first transmitting electrode 312 is located within each electrode group, and transmits signals at wavelength intervals of the corresponding close eye wavelength V''. Group position N that provides wavelength divisions for close eyes obtained by dividing the wavelength Wtt and dividing each interval into N equal parts.
Occupy an individual portion. This arrangement of first transmitter electrodes allows the width of each transmitter electrode in the measurement direction to increase in proportion to the scale wavelength, and is proposed in a co-pending U.S. patent application filed by the applicant.
Capacitive measuring transducer with improved measuring element arrangement) describes this in detail.

As shown in FIG. 2A, the corresponding first
The transmitting electrodes 312 are electrically coupled by a coupling element 314, with the last set of electrodes 312 coupled to a corresponding transducer input terminal 316 such that an excitation signal is coupled to the terminal 316 of the corresponding electrode 312 of each electrode group. A predetermined value corresponding to the received signal is received.

In FIGS. 1 and 2, a second
As shown, the transmitting electrode row 220A is composed of a row of second transmitting electrodes 222A adjacent to one side of the electrode row 210A and corresponding to each electrode 210A. Each second transmitting electrode 222A
is connected to one of the corresponding receiving electrodes 212A via a connecting electrode 224A, so that each node 2 transmitting electrode 222A has a second transmitting electrode relative to a reference point Re on a measurement axis (not shown) relative to the first receiving electrode 212A. It is decentered or replaced at a position corresponding to the function value Da(X) determined based on the position of 222A. Furthermore, as a result, the deviation between the transmitting electrode 222A and the corresponding receiving electrode 212A is the maximum value of a predetermined coarse measurement range, or the transmitting wavelength Wt that spans the wavelength We (not shown).
It does not change even if the value exceeds t.

Next, the deviation of the electrode is determined by the second transmitting electrode 222A with respect to the reference point.
increases linearly with increasing distance.

However, the electrode excursion and the corresponding positional relationship of the second transmitting electrode can be non-linear. Furthermore, the second transmitting electrode 2
In order to linearly deform the electrode eccentricity and the corresponding position of the second transmitting electrode 22A, as shown in the figure, the electrodes are spaced from each other by a uniform pitch Pt2 different from the pitch Prl. For such an arrangement, the deviation Dc(X)
has the following relationship.

DC(X)=(Pt2-Prl)r (X)['(X)
-X/Pr1 Da(X)-(Pt2-Prl)X/Prl where X means the distance from the reference point to the second transmitting electrode.

The electrode deflection is related to a reference point Re, which is one end of the coarse wavelength We of the caliper, as in the embodiment of FIGS. 1-2, or one end of the coarse wavelength We, as shown in FIG. It may also be the midpoint of the wavelength We. In the arrays shown in FIGS. 1 and 2, the electrode Is position differs for each electrode pair, and in the arrangement shown in FIG. are equal, but in opposite directions to the measurement axis, as shown. Thus, in the embodiment illustrated in FIG.
) changes within the range of +1/2 to -172 of the transmission wavelength Wtt. The advantage of the symmetrical deflection shape of the embodiment shown in FIG. 3 is that the maximum deflection Da(X) is limited, and the values of the inclination and length of the connecting electrode 224 are reduced, making manufacturing easier. That's true.

As shown in the figure, the third transmitting electrode row 220B arranged on the support member 20 is located on the opposite side from the second transmitting row 220A, and has a single third transmitting electrode 222B arranged in parallel corresponding to each first receiving electrode 210B. It becomes more. A group of receiving electrodes 212B is electrically coupled to a corresponding group of transmitting electrodes 222B via coupling electrodes 224B as shown. 1st
Within each group connecting the receiving electrode and the third transmitting electrode,
The S3 transmitting electrode 222B is eccentric with respect to the associated first receiving electrode, and both are connected to the second transmitting electrode 222A and the first receiving electrode 2.
It is connected in the same way as the connection with 12A.

The deviation amount D+g(X) of each group is a position determining variable (linear or nonlinear) of the third transmitting electrode 222B with respect to the reference point Rs on the measurement axis within the group. The deviation Da(X) exceeds the measurement distance such as the intermediate wavelength Wn, and the third transmitting electrode 2
22B, it is equal to the transmission wavelength Wtt. Furthermore, as shown in Figure 6, the group reference point Rn+ is located at the center of each group, and the deviation Da(X) within each group is +l// of the transmission wavelength with respect to the reference point.
It varies within the range of 2 to -f/2. Additionally, the intermediate wavelength should preferably be an integer multiple of the transmitted wavelength. The groups are repeated at equal intervals for the intermediate wavelength w-.

Furthermore, the coarse wavelength We must be an integral multiple of the intermediate wavelength vIll, and the intermediate wavelength Vl must be an integral multiple of the close wavelength V. In addition, the intermediate wavelength Wm is an integral multiple of the transmission wavelength Wtt. Coarse analysis measurement requires determining where the measurement point is located in the intermediate wavelength, and it is necessary to limit the measurement of the fine wavelength measurement position.Therefore, the accuracy of the intermediate measurement The accuracy of the coarse measurement must be higher than one intermediate wavelength, and the accuracy of the coarse measurement must be higher than one intermediate wavelength.

Therefore, the relationships among the coarse, medium, and fine wavelengths we, w■, and wr should be selected depending on the accuracy. for example,
In the embodiment shown in FIG. 2, N is 8 and Vc-40VmsVm
--A Of, in the interpolation analysis of 1/320 coarse and medium measurements, the coarse measurement is 1/320 of the intermediate wavelength.
It is possible to determine the position within a range of 8. This is a high limit that can be kept within a maximum error of -wavelength or less. For example, for Wf'-1,024 + am, the interpolation analysis would be W'1512 or 2 microns. For the full range of absolute measurements, for results with a total range greater than 2 microns, 40 x 40 x L ,024
an-1638sn-1,84Il.

The third transmitting electrodes 222B are uniformly spaced from each other by a pitch Pt3, and the deflection DIl(X) of the third transmitting electrodes is determined linearly with respect to the corresponding positions of the electrodes in the group. As shown in Fig. 1 and Fig. ff13, the pitch Pt3 is the third
The associated first transmitting electrode 212B is connected to the third transmitting electrode over a distance (medium wavelength Ws) of one group of transmitting electrodes.
It is sufficient if the distance is smaller (Fig. 1) or larger (Fig. 3) than the distance spanning the group. In the arrangement shown in Figure 1, the first
The transmitting electrodes 212 may be coupled to corresponding third transmitting electrodes, but not all third transmitting electrodes can be coupled to corresponding first transmitting electrodes. Furthermore, the arrangement shown in FIG. 3 may be reversed. At least in the case of the arrangement shown in Figure 1,
It is desirable that the transmitting electrode 222B-, which is not connected to the receiving electrode 212B, be connected to the base conductor 225 (FIG. 2).

The second receiving electrode row 320A on the support member 30 has two second receiving electrodes 322A, 322A, which are adjacent to each other and have mutually complementary shapes, on the opposite side from the second transmitting electrode row 220A.
- has. As shown in the figure, the electrode is long and has a shape that changes periodically with respect to the measurement axis. Electrode 322A, 3
The effective length of 22.1 m is an integral multiple of the transmission wavelength Wtt. From the viewpoint of signal processing, a sine curve shape as shown in FIG. 1 is desired. However, triangular or rectangular shapes as shown in FIG. 2 can also be used.

One type of rectangular shape is shown in FIG. 4, where the second receiving electrode row has a row of rectangular electrode units 324 disposed on the support member 30 on the opposite side from the second transmitting electrode row.

As shown in the figure, the electrodes 324 are maintained at regular intervals and are alternately connected to the anode and cathode of the signal processing circuit 104. In this way, the electrode 324 has a predetermined wavelength Wt, which will be described in detail below, with respect to the measurement axis.
It intensively has a periodic shape with 2.

A periodically varying signal (or groove phase by combination of signals as detailed below) for each group of N first transmitting electrodes 312 according to the physical position to which one of the electrodes in the group corresponds. is emitted 0 times in a row, the composite electric field distribution on the first transmitting electrode 312 has a wavelength W
t, and this distribution is capacitively coupled to the first receiving electrode 212A, and is connected to each second receiving electrode from the reference point Re via the coupling electrode 224.
Deflection DC with respect to the support member 20 depending on the distance of the transmitting electrode
(X) communicates with the second transmitting electrode 222A. When the second receiving electrodes 322A, 322A- are connected separately, the deviation with respect to the predetermined reference point on the support member 20 depends on the correlated deviation Dc(X) of the second transmitting electrode, as described above. It acts as a spatial filter to detect electric field elements. The same deviation Dc(X) is preferably a linear variation, and the second receiving electrode has a periodic shape or the first receiving electrode 212A standardizes the difference in pitch between the second transmitting electrode 222A. This can be achieved by receiving a wavelength Wt2 that detects an electric field element having the wavelength of the transmitting electrode Wtt. That is, the second receiving electrode has a shape that allows it to sense the electric field pattern of the receiving wavelength Wt2 having the following relationship with the transmitting wavelength.

Wr2=Wtl(Pt2/Pr1) The third receiving electrode row 320B has the same shape as the electrode 320A, and is located on the opposite side from the third transmitting electrode 220B. Third reception wavelength Wr3 that satisfies the condition of the following formula for the transmission wavelength
The second receiving electrode 3 of the electrode row 320B can detect the electric field pattern generated by the third transmitting electrode 222B.
22B has the same shape as the electrode row 320A.

Wrl-Wtl (Pt3/Pr1) In FIG. 3, instead of the single row 210 of the first receiving electrodes 212, double rows 21OA and 210B as shown in FIG. 1 may be adopted. In the embodiment of FIG. 3, the second transmitting electrode 22 is
0A is connected to one end of the first transmitting electrode, and the third transmitting electrode 22
0B is connected to the other end of the first receiving electrode. Additionally, as shown in FIG. 1, the first receiving electrodes may be sinusoidal, and the spacing between the electrodes forms a substantially sinusoidal waveform parallel to the measurement axis.

In the close eye measurement mode, the second receiving electrodes 322A and 3
The output terminals of 22A- are connected together. As a result, the electrode array 320A has the effect of a rectangular electrode extending over the entire length of the transmission wavelength Wtt. Similarly, the output terminals of the third receiving electrodes 322B, 322B' function as rectangular electrodes extending over the entire length of the transmission wavelength, so that they are connected. The signal inputted from the first transmitting electrode 312 to the connected second receiving electrode 320A through the first receiving electrode 212A and the second transmitting electrode 222A connected thereto has a wavelength equal to the wavelength Wrl of the first receiving electrode row 210A. The position X between the pointing members 20 and 30, which corresponds to the reference point of the support member, changes periodically as a variable.

Similarly, a third electrode connected from the first transmitting electrode via the second receiving electrode 212B and the third transmitting electrode 222B continuous thereto.
The signal input to the receiving electrode 320B follows a similar periodic function offset by 180@ with respect to the signal generated by the connected second receiving electrode 320A.

These first transmitting electrodes and second/third receiving electrodes 320A/3
The shape of these signal switching features between the close eye mode structures of 20B depends on the shapes of the first transmit and first receive electrodes. If the electrodes are rectangular, the conversion function is provided by the support member 20.
．． It is a mixture of triangular waveforms between small intervals of 3o, and becomes a sine waveform as the interval widens. As shown in Figure 1, the first
By forming the receiving electrode into a sine wave shape, the sine waveform conversion function becomes independent of the spacing between the supporting members.

In the first electrode of the first transmitting electrode, the above-mentioned close eye conversion function rn is mathematically expressed as TI'l''Cro+Cf 5in (2πX/wf'), where C'0 is the capacitance constant and C' is the amplitude of the variable capacitance.

The second electrode of the first transmitting electrode is separated by a distance of 1Ild (in the X-axis measurement direction) from the first electrode of the first transmitting electrode described above, and the fine mode conversion function TT2 is expressed by the following equation in the relationship of d to the Tfl function. It becomes like this.

Tf'2(d)-Cf'o+Cr sin [12x
(X-d)l/Wf'] The spacing d between the first transmitting electrodes selected as described above and described in the applicant's aforementioned pending application is the first transmitting electrode spacing d of the group of N electrodes. One transmitting electrode spans a number of wavelengths Vr, and the distance dn from the first electrode to the nth electrode in the -group can be expressed as in the following equation.

dn=n(Wf/N)+(Mn) (Wr) where Mn
is an integer corresponding to the scale wavelength interval at which the nth electrode in the group is located.

In the dense ill constant, Mn is an arbitrary integer value. This is because 5in(V+M2π)-sin(V) (when M is an integer).

The transmission variable of the first transmitting electrode at each phase position within the group is defined as follows, independent of M.

Tn-Cro+CI' sln[2w ((X/Wl'
)-n/N)] This means that the first receiving electrodes N in a group constitute N phase electrodes with sign-change variables that are 3600 phase-shifted from each other.

In the coarse and medium measurement, the output of the second and third receiving electrodes is, for example, the processed coarse b11 signal is transmitted to the second receiving electrode 3.
22A, 322A'', and the processed medium-grain measurement signal is different from the signal from the third receiving electrode.Especially in the coarse measurement mode (the description for the medium-grain measurement mode is similar) , since the shape of the second receiving electrode is divided into a sine wave shape as shown in FIG. 1, the capacitance between the second transmitting electrode 222A is calculated as )=Cco+Cc sln[2yr ((X/
Wr2)-n/Nl]. Here, Cco is a capacitance constant, and Cc indicates the amplitude of the variable capacitance. The corresponding capacitance variable at the second receiving electrode (sub) 322A' is defined as follows.

C”(X)=Cco−Cc sin[2πl(X/Wr
2) -n/Nl1The difference between both capacitance functions is C(X)=C'(X)-C''(X)-2Cc sin[
2W l (X/Vr2)-n/Nl ].

ml receiving electrode 212 from the first electrode of the first transmitting electrode 312
A and the second receiving electrode 322A via the second transmitting electrode 222A.
The transformation variables of the signal input to A, 322A'' are those that are combined by the fine wavelength modulation produced by the first receiving electrode and the capacitance function described above.

Tel (×) ” (Cfo ” Cf ” (drunk)) tCco 10 cc 'branch n(1,, -(c,.)
Cc 5in (guard 1) (Cco -Cc 5in(
"F"' l) "(Cfo" Cf 5Ln(Q
l 1 +2Cc 5in(";F" ))・The first electrode separated by N/2 phase from the first electrode of the first transmitting electrode described above.
The second electrode of the transmitting electrode has a fine and coarse inverse sine function, and the transfer function to the second receiving electrode is Tc2(X)=-[C1'o-Cr51n(2rX/Wf')]12
cc sin[2πD(X)/We]l.

A signal that is the reciprocal of the signal supplied to the first electrode of the first transmitting electrode is supplied to the second electrode of the first transmitting electrode, and due to the combination of the two first transmitting electrodes, the following composite conversion function results.

Tc(X)=Tel(X)−Tc2(X)=4(Cr
o) (Co) (sln(2tr D(X)/We)
) The composite conversion function is thus independent of the fine wavelength variable of the first receiving electrode, and the deviation D between the first receiving electrode 212 and the adjacent second transmitting electrode 222A that can be used for coarse measurements. Only (X) is dependent.

As mentioned above, the array of transmitting electrodes of the present invention may utilize a spatial filter, and the filtering function may be determined by the coupling structure of the transducer (tight wavelength modulation by the first receiving electrode or deviation D (X) The coupling structure is made by wiring the output of the second receiving electrode to a different electrical wiring in order to bring out the desired components of the signal distribution (tuned transmit wavelength signal distribution across the second transmitting electrode) and exclude other components. You can change it by changing it.

As described above, the second and third receiving electrodes 322A.

322A'', 322B, and 322B= have various coupling structures, and the dividing line between each connected electrode row can have a triangular or rectangular shape in addition to a sine wave shape.

Compatible electrode arrays such as 2 provide the above-mentioned spatial filter as long as the transformation constant between the second transmitting electrode and the second receiving electrode satisfies C(X)=C(X-(wr2/2)). can do.

It may depend on the relative position of the transducer support member 20.30 with respect to the fundamental relationship with the measurement position to be determined by measuring the phase difference over the spatial position of the corresponding transducer output signal waveform with respect to the reference point.

According to the invention, the absolute measurement is derived by a combination of coarse and close discrimination measurements based on at least the logic described above. The combination of coarse, medium, and fine discrimination measurements is utilized to obtain accurate absolute measurements over an extended measurement range. The composite measurement outputs the excitation signal or mixed phase a predetermined number of times to the first transmitting electrode according to different measurement modes, and tjS2 to provide a suitable spatial filter.
, can also be obtained by the same electrode row by connecting to the third receiving electrode. The arrangement structure of the first, second and third transmitting electrodes can perform N distributed phase points due to the capacitance function with closely spaced wavelengths, and the first receiving electrode and the second,
The deviations DC(X) and DH(
It is possible to obtain N-divided phases with long wavelengths spanning several wavelengths, providing coarse and medium position information for X).

The separate transfer function described above is the basic capacity function. For each measurement mode (coarse, medium, fine), each measurement wavelength WeSw
- and absolute position within Vr is measured with several different known circuits for capacitive position measurement. No. 4,420.75 of the aforementioned applicant's pending application, which is referenced herein, or applicant's U.S. Patent No. 4.420.75.
The circuit described in 4 is given as an example. Such a circuit, based on the continuous excitation of the transmitting electrodes with cycles No. 13 of different phases, is equally divided into four inputs, and the receiving and analyzing circuit is based on the measurement of the relative phase positions of the composite mixed signal. is determined by the following limitations.

a) When using the same excitation signal for the selected transmitting electrode or all measurement modes continuously for coarse, medium, and close measurements, the above three types of parallel circuits can be used simultaneously. and absolute position quantities can be calculated from the outputs from these measurements.

b) If the selected transfer electrode arrangement requires continuous coupling with different excitation signals for fine, medium/coarse measurements, measurements are performed multiple times between each measurement mode.

C) When three measurement modes (coarse, medium, and fine) are continuously multiplexed through the same measurement circuit, in each measurement mode, a stable state (differentiator, integral Sufficient time is allowed for the signal to take a certain period of time in the device.

An embodiment of the electronic measuring device is shown in FIG. The embodiment shown in the figure has the advantage that measurement can be performed faster than the continuous signal phase measurement method described above, and that multiplex transmission can be performed through a common electronic measurement circuit without requiring time setting between the three modes. In general, the apparatus of FIG. 5 measures the proportion of the transducer transmitted output resulting from different group phase combinations of the excitation signal during each measurement mode by a dual lamp analog-to-digital conversion method.

The following description is a description of an exemplary implementation of transducer 12 having the electrode geometry shown in FIG. 2 and the parameters described below.

Wavelength; VFml, 024+u Va+-40Wf'-40,098a+mVc"40W
g=183L4mm Pitch of first transmitting electrode DItch - 5/8 (Vr) Total number of group phase combinations of excitation signals - 8 Continuous relationship of excitation signals in each group of N first transmitting electrodes Coarse/medium measurement mode 1 -2-3-4-5-6-7-8
Close eye measurement mode 1-8-3-8-5-2-7-4
As shown, the electronic measuring device of FIG. 5 has a microprocessor-control 110 that controls the operation of the other elements and performs the necessary calculations in the combination of measurement results, and an excitation signal 400 for control signals generated by the control 110. A control signal 1 produced by a transducer excitation signal generator, controller 110, which produces a predetermined group phase combination of
Output 410 of the third receiving electrode row 320 and output 4 of the third receiving electrode row 320B in different combinations corresponding to No. 13
20 and a response transducer output signal combiner 130 for continuous processing according to a measurement mode, as detailed below, corresponding to the control signal and transmitting the different transmission paths and channels through the transducer. a dual ramp A/D converter 140 and a control signal 114 corresponding to a pair of amplitude ratios of a continuous response transmit output signal 430 corresponding to a time interval T during which position measurements for each measurement mode can be drawn by the controller 110; In response to output signal 115 produced by controller 110, controller 1
10 includes a display 150 for representing the position values calculated by 10.

As shown in FIG. 5, the transducer excitation signal generator is
It includes a clock oscillator 122 for generating a high frequency rectangular clock signal 123 having an oscillating frequency and a modulator 128 for predetermined continuation (group phase mixing) of the converted and unconverted signal 123 as the transducer excitation signal 400. Preferably, a clock frequency of 0 can be selected such that each clock cycle corresponds to a phase difference represented by an increase in the dense wavelength response.Moreover, as shown, the modulator 128 has exclusive or gates 128-1 through 12
8-8 columns, each gate inputs a clock signal 123, one gate control signal 127-1 to 127-8 generated by a ROM 126 (ROMI) corresponding to a corresponding control signal controller 112. .

As shown in the table of FIG. 6, the control signal 112 is a 4-bit binary code whose values are determined by U, V, M, P/MCI, and 16 sets of ROM1 outputs 127-1 to 127-8. Different combinations of phases are used: eight for the fine (F) measurement mode (bit P/nc = 1) and eight for the medium (M), coarse (c) measurement mode (bit P/nc = 0). ing. (Those skilled in the art will appreciate that when the gate control signal 127 is low, the excitation signal produced by the series of gates 128 is the clock signal; when the gate control signal is high, the excitation signal produced is inverted with respect to signal 123. (This is self-evident.) As shown in FIG. 5, the excitation signal generation 12
The excitation signal 400 generated by 0 is concatenated according to a fixed consecutive number of transducer input terminals 316-1 to 316-8 corresponding to each terminal of a corresponding first transmitting electrode of each group of N electrodes. Ru.

That is, the first signal 400-1 is input to the first transmitting electrode 312-1 of each group, and 'l! The N.52 signal 400-2 is input to the second transmitting electrode 312-2 of each group, and the Nth signal 400-N is input to the Nth transmitting electrode 312-N of each group. Therefore, in coarse and medium measurement modes, the various combination group phases are 4 consecutive non-inverting and 4
Consisting of two successive inverted excitation signals, each non-inverted and inverted signal is input into each group, in which the electrodes continuously transform by one electrode group phase position from one position combination group phase to the next phase. That is, at a combination group phase of -0 as shown in FIG. will be sent. Next consecutive combination group phase (K-
In 1), non-inverted signals are received from terminals 316-2 to 316-5, and non-inverted signals are received from terminals 316-6 to 316-1.

On the other hand, in the close measurement mode, due to the electrode arrangement as shown, the same combination group phase of the excitation signal 400 is determined by each phase according to the corresponding phase position (close wavelength division position) of each electrode in the group. The first transmitter electrode in the group must be entered. The fixed relationship of the excitation signal oscillator output 400 to the transducer input terminals requires a second set of combined group positions as shown in FIG. The relationship between each input terminal 316 is as follows.

Terminal Number Electrode Segment Position 316-1 1 316-2 6 316-3 3 316-4 8 316-5 5 16-62 316-7 7 316-8 4 The output of the excitation signal generator 120 is the only one of the excitation signals. A set of two combined group phases is coupled to the transmit input terminal 316 via a control interface circuit that determines the number of times each excitation signal is delivered to the input terminal. In other transducer electrode arrangements, for example, when N-8, wtt -9w'l, and the number of times each sub-wavelength segment position occupied by the first transmitting electrode in each group is 1-2-3-4- 5-6-7-8, and the same set of combination group phases can be used for both coarse/medium or fine measurements.

As shown in FIG. 5, the transducer output signal synthesizer includes an electronic switch network 132 for a bifurcated switch control signal generated by ROM 134 (ROM2) and a switch network 132 for a 22-bit word control signal indicative of the measurement mode. , and has a differential amplitude circuit 136 coupled to the output of the transducer output signal 430 and producing a composite transducer output signal 430 as an output. As shown, switch network 132 includes transducer outputs 410, 42
It has four input terminals A, B, C and D each connected to 0. Switch Sll, S12. S13, S14. S
21. S23. S24. S25 and S26 correspond to FIG. 72 as shown in FIG. 7, and the corresponding control signals are high (7th
When "■" in the figure, the switch is in the UP position (switch 511) in Figure 5, and the corresponding control signal is low (
When the switch is "O" in Figure 7, the switch is down in Figure 5.
It is in position n. The switches Sll to S26 are interconnected as shown, and their combined signal 430 constitutes the following input combinations for the values that the switch control signal 133 has for each of the three measurement modes shown in FIG.

Dense: Signal 430-(A+B)-(C+D) Medium: Signal 430-C-D Coarse: Signal 430 A-B As shown in FIG. The resulting composite transducer output signal 4
demodulated DC transducer signal 4 proportional to the amplitude of 30
40, a dual larep integral run pair of a tuned demodulator and a transducer signal 440, described in more detail below, is controlled by the same clock signal 123 used to generate the excitation signal 400. an integrator 144 for the control signal and a comparator 146 that detects the zero point of the integrated output signal 450 produced by the magnetic polarity and integrator 144, described in more detail below, and produces a feedback signal 115 used by the controller 110. including.

The controller 110 includes a transducer excitation signal generator 120, a transducer output signal synthesizer 130 and an A/
A program is provided to control the D converter to 0 and calculate a measured value to obtain a position value according to the flowchart shown in Figures 8A-8E. In FIG. 8A illustrating a master measurement duram controlling position measurements, controller 110 initiates measurements in the normal manner at step 100.
0), the coarse/medium/fine mode measurement subprogram (steps 51200, 51300, 51400) is the coarse/medium/fine composite measurement position value M c.

This is done continuously to obtain Mm and Mf. As will be explained in detail below, the medium and close eye mode measurement subprograms are operated to cause corrections, and more precisely to cause corrections of the measured position values obtained by previous measurements. After the end of the close eye mode measurement subprogram, three measured position values Me are obtained.

A final value of MmSMf is selected and the measured position is transformed (step 51500) to an absolute position measurement M9. The measurement cycle ends with normal processing operations (step 51600) in conjunction with the display of position measurements on display 170. For example, such operations can correct position measurements for zero offset, convert position measurements to inches, convert binary values to an appropriate output format, such as BCD notation, and convert them to a desired display format. .

As detailed below, the demodulated composite transducer output signal 440 A/D conversion for each measurement mode is graphically illustrated at the required size for the transducer 12, so that it can be placed in the hook scale position data. Each incremental change has the following relationship to the placement of the transducer pointing member with respect to the measurement axis:

Dense mode: Medium mode: Coarse mode: 1 data increment - 1024151 2 - microns 1 datum - 40x1024/3 20 - 128 minlons 1 increment - 40x1024/32 0 - 5120120 microns, scale corresponding to position measurement (step 1500) The plate value conversion simply requires merging the three scale positions according to the weighted formula below.

Mp-2Mf+128Mm+5120Mc As shown in Fig. 8B and Fig. 8D, in the three measurement modes of coarse, medium, and fine, the same A/D conversion subprogram (ABC) (steps 51240, 31340, 51
440) are respectively performed. In each measurement mode, the controller 110 first selects one of the N possible group phase combinations of the emitted transducer excitation signal 400 and performs the process as described in detail below. , the signal synthesizer 130 is controlled to generate the appropriate resulting transducer output signal for each 7111 constant mode. Flowchart FIG. 8E shows that the ADC subprogram control amount 110 is initially
is reset to a predetermined zero output voltage (step 1710). (For those skilled in the art, the zero level of the integrator need not be absolutely zero voltage, and a predetermined voltage may be selected as the signal zero level based on the design of the circuit.

) The controller 110 then causes the integrator to integrate the demodulated and synthesized transducer output signal per predetermined time interval To (S1720).

The controller 110 then checks the polarity of the integrator output 450 sensed by the comparator 140 (signal 115) (step 51730), and the polarity indicating constant P is set in the range of plus or minus 1 according to the sensed polarity (S1740.51750). be done. Controller 110 selects a new group phase combination of transducer excitation signal 400 (step 51760).
The demodulated combined transducer output signal 440 resulting from the new group phase combination of the excitation signals is integrated by comparator 146 until it is sensed that integrator output 144 reaches zero (step 1770).
. During the second integration, the integration time T is increased by clock signal 120 until comparator output signal 115 indicates an integral output of 0.
is measured by an integral counter within controller 110 that adds up. If the integrated output during the second integration interval does not reach zero within the predetermined period Tmax, each measurement mode subprogram enters the outer loop of the ADC subprogram (step 51720);
, as detailed below, changes the phase combination of the group of excitation signals to generate the integrated initial transducer output signal 440 during the initial integration of the ADC subprogram.

As mentioned above, the purpose of the ADC subprogram is to generate signals closer to the coordinate axes for the fine, coarse, and medium transmit functions mentioned above, and to generate signals from a set of combined phases of excitation signals for the resulting measurement mode. One of the transducer output signals that can be generated 11) is to find out the ratio of the composite transducer output signal due to the moving function that is 174 wavelengths shifted from the initial signal. In Fig. 10, when the actual measurement position Xp is located as shown in the figure with respect to the coordinate axis The first integration performed by the unit 144 is the output volt Vl -Vs im (2π (X/W-1/8)
Generates 1. where V is equal to the input volts of the excitation signal 400 and W is equal to the coarse, medium, and fine wavelengths. During the first integration period, the final output volts of the integrator is the composite voltage Vl over time To.

For Figure 9, the voltage Vt is an electrostatic voltage and the next integrator is the excitation signal K + which results in the inverse integration of the output of the integrator.
2-3 with the result of the transducer output signal from the group combination phase. That is, the input terminal to the integrator has the amplitude V3-V sin (2tr
(X/W-3/8)). This signal is 90" out of phase with the first signal (though negative in this example) and the integrator output decreases towards zero. At time T, when the integrator signal goes to zero, VI To
−Vs T−0°, that is, T −To (Vl
/V3) (D-related (E).

MI Vs is due to a sine function Xp, and the relative position of the transducer pointing member with respect to the base point, Vs, is 90@ out of phase with Vt, and the above equation for T is a tangent function: T-To t an ( 2π(x/W-1/8)).

This tangent function rises to 22.5@ (W/10) accordingly. The value T is therefore used as measurement data for further linear calculations in order to determine measurement positions that can be placed within this range. (If higher accuracy is desired, the deviation of the tangent function from the line spacing number can be corrected by continuous arithmetic processing.) For factories on the above-mentioned straight line of the tangent function, the excitation signal Given a group combination phase within a limited portion
A comparison of the second integration time T with a predetermined maximum value establishes that the measurement is carried out within this range. If this time T exceeds a predetermined maximum value, a new combined phase of the excitation degree signal is used as the initial integration and the process is repeated until a second integration time T is obtained within predetermined limits.

As a specific example of the exemplary embodiment of the transducer 12 described above, the 320 (zero 40 x 8) scale position increases from time to time in each measurement mode until the position coarse wavelength WC1 becomes the medium wavelength; 64x8) The scale position value is the first density wavelength w4 in the density measurement mode.
increases to be equal to . Spatial range X mini 836
0/1B) degree is coarse ◆820/18 in medium mode
-20 data increase, 512/1B in close eye mode 1
- Corresponds to 32 data increase. A value larger than these two values in each corresponding measurement mode is the spatial range
It will be outside of a. The relationship between the integration time To and Taax is Tsax-20-Tojan (38G/1B) in the coarse/medium mode, and Taax=32-ToLan (360/1B) in the close mode.

This relationship yields a value of 48 clock cycles for time To in the coarse-to-medium mode and 77 clock cycles in the fine-grain mode.

FIG. 8B shows that the coarse measurement mode subprogram generates a control signal that causes the composite transducer output signal combiner 130 to produce the composite transducer output signal combiner 30 in the appropriate coarse measurement mode described above. Indicates that it will be started. The controller 110 then selects the group combination phase number K from among the coarse/medium combinations shown in FIG. 8 (step 51220). Preferably,! aK is set equal to the value Kc calculated during the previous coarse measurement. In most cases, the rate of change in the value of the measured position value is not large, and the standard for this selection is a number that is very close to the corrected value of the measured position. If there is no previous Ktn, for example, the caliper is output OF
When approaching from F mode, any value of K can be the initial value. The program continues to iterate through the coarse measurement mode until the corrected value of K is reached.

Once K11lI is selected, the group combination phase of the corresponding transducer excitation signal is generated (step 51230) and the ADC subprogram described above is performed. The second integration time value T generated by the ADC subprogram is compared to Tmax in the coarse measurement mode (20 in the exemplary embodiment described above) (step 51250). If the value of T is greater than or equal to 20, the number of K is adjusted up or down by one step by the P value produced by the ADC subprogram (step 51260). The measurement loop (steps 51230-31260) is then repeated in response to a new number being selected for the initial group combination phase of the generated excitation signal to generate the initial composite transducer output signal 430. This process continues until the value of time T is greater than the value 20 obtained from the ADC subprogram.

The value Kc is then updated to K during a measurement time T within predetermined limits. The value Kc is used as an initial value for the next coarse measurement and is also used to obtain the value Me for the coarse scale position value. In the typical example mentioned above, it is Me-40Kc+PT.

In a typical example, MC can have values from 0 to 319. When the calculated value of Me is outside this range, the controller 110 performs a warp-around calculation such that the calculated value 321 is measured 1iil! 1, and the calculated value -3 is equal to the measured value 317. By selecting the coarse liquid level measurement result to be 320, Mc
Each increment in value is dedicated to 1/(40X8)-1 phase step (equal to the increment in medium measurement mode).

FIG. 8C shows that the medium measurement mode subprogram is substantially equivalent to the coarse mode subprogram.

The controller 110 includes a signal synthesizer 1 for producing a transmit transducer output signal 430 suitable for medium-sized measurements.
30 (step S 1310). Then (step 5132
0), the controller calculates the number of group phase combinations of excitation signals from among the coarse and medium combinations shown in FIG. Unlike the coarse mode subprogram, the medium mode subprogram uses the coarse scale position value obtained from the coarse mode calculation using the equation % integral value.

Controller 110 then generates a group combination phase K of excitation signals to perform the ADC subprogram (steps 51330, 51340). Similar to the coarse mode subprogram, the value used in the operation K is adjusted up or down by one step according to Pwi produced by the ADC subprogram (step 81360). The measurement loop (steps 51320-81360) is then repeated again according to the corresponding new numbers. This process is repeated until a value of the second integration time T within predetermined limits is obtained from the ADC subprogram. The value of Kn is new (step 51370) and the middle lo-scale position value Mm is (in the exemplary embodiment) given by the equation M-=40.
+PT (step 31380).

The medium measurement mode performs a warp-around operation similar to that used in the coarse measurement mode to derive Mslii. - Selecting 320 as the medium wavelength results in one increment in the medium measurement mode, i.e. l/40 x 8-1 phase steps (I
K increase).

FIG. 8D shows that the close eye measurement mode subprogram is generally equivalent to the medium eye mode subprogram. Controller 110 begins by setting the signal synthesizer to generate the appropriate composite transducer output signal 430 for the close eye measurement (step 514).
10). Next, the controller 110 calculates a number for the initial group combination phase of the excitation signal using the previously calculated middle scale position 17M+g based on the following equation (step 51420).

K-Mm-N(Int(Mm/N)) After the second combined phase of the excitation signal is generated (
Step 81430), an ADC subprogram is performed (step 51440)*. Similar to the coarse/medium measurement mode, if the calculation 1if (T exceeds the limit Tla Increased (step 51450.5146
0). If this adjustment causes the M-value to pass through 31910 values in either the up or down direction (step 514
62), the Me value increases or decreases by one in accordance with one increase. The measurement routine (steps 51420-31464) is then repeated again with a new number until the ADCD program yields a time wlT within the limit Tsax. The value of Kf is then changed to the first operation ii K (step SL, 470), and the close scale position value Mf is determined by the equation (in an exemplary embodiment) Mf-64K
s+PT (step 31480
).

With the dimensions in the illustrated example, the value Ml' is 0-51
Values can be set within one range. Similarly in the other two modes, if the calculated value Mf' exceeds this range, the controller 110 performs a warp-around calculation. For example, the calculated value 513 is equal to one measurement, and the calculated value -3 is equal to the measured value 509. - The selection of the composite value 512 at the dense wavelength V' results in an increase equal to the dense wavelength needle of 1/(64X8)-11512 (2 microns if the wavelength is 1.024 M-) in the dense scale position measurement. Become.

The main measurement program conversion step 51500 is performed by using liWMc, Ms, Mf' obtained by performing all three measurement mode subprograms as described above. The initial value of Me obtained by performing the coarse mode subprogram may be continuously demodulated during the medium and close mode subprograms. The initial value of the eye frame may be demodulated during the close eye mode subprogram (steps 51450.51460) as described above.

Provision may be made in the medium or close 8-1 constant mode subprogram to continually correct the high wavelength measurement data based on results from the low wavelengths.

This is because the least significant bit of the high frequency wavelength measurement, which is the bit in the next lower wavelength corresponding to the Kl& character, is somewhat obscure. In the low wavelength measurement mode, the value of the K number is tested in the ADCD program with a high level of accuracy. Therefore, by reflecting the high wavelength measurements, any adjustments in the numerical values in the low wavelength conversion and the ambiguities in the high wavelength measurements are resolved and a corrected position measurement is obtained.

The embodiments described above are merely illustrative of the present invention, and the numerical values may be changed without departing from the spirit of the present invention. In particular, the embodiments described herein may use a combination of coarse, medium, and fine grains to obtain accurate absolute position measurements. According to the present invention, the main feature of the coarse composite measurement is the arrangement of the first receiving electrode and the second transmitting electrode, that is, the second transmitting electrode is connected eccentrically to the corresponding first receiving electrode, This means that the first receiving electrode is located at a position indicated by a predetermined function with respect to the position of the second transmitting electrode with respect to the reference point, and the eccentricity function D (
x). An aspect of the present invention is that it is not dependent on the particular arrangement of the first transmitting and second receiving electrodes, nor on the signal processing method employed to represent the capacitance function. In coarse measurement,
As long as the arrangement of the first transmitting electrode and the shape of the second receiving electrode, which is adjusted for the eccentricity ratio between the first receiving electrode and the second transmitting electrode, match, the first transmitting electrode does not need to have a uniform arrangement; As a result, it is not necessary that the transmission wavelengths Wtt within the group of N first transmitting electrodes are equal for the entire group.

Furthermore, the number N of first transmitting electrodes in one group can have a minimum value of two.

In addition, the arrangement of the first receiving electrode is not the main pattern factor for coarse measurements according to the present invention. The intervals between the first receiving electrodes may be completely random.

by providing a transmitting function for combining a plurality of transmitting channels placed on a group of first transmitting electrodes and going from the first transmitting electrode via the first receiving electrode and the second transmitting electrode to the second receiving electrode; - It is possible to perform coarse measurements smaller than one first receiving electrode per transmission wavelength Wtt.

If the number of such channels is 3 or more, the width of the first receiving electrode is not an integer multiple of the first transmitting wavelength Wtt, and it is possible to determine the function D(X), thereby obtaining a coarse position measurement. I can do it. (The transmission channel starts from the connection of the excitation signal, passes through the first receiving electrode, and then passes through the N of the first transmitting electrode group.
up to the first transmitting electrode of the second transmitting electrode and up to one of the second receiving electrodes of the second transmitting electrode. As mentioned above, 1
The two second receiving electrode connections can be two connections with different poles. A more limited transmission channel is obtained by joining together several such connections, as in the embodiments described above. ) Each transmission channel has a possible function that allows placement between the first and second support members (i.e. function X). The amplitude of the exchange function is not required, but is preferably equal for all of the transmitted channels, and the same function is
direction) is out of phase.

The shape of the exchange function is, for example, sine, triangle, square,
Any other predetermined shape may be used. The exchange function of the sine shape is f8
This is preferred because the dependence of the exchange function on the gap between the first or second indicating member is low. Two transmit channels that are 1/4 wavelength out of phase in the X direction have, in principle, enough information to determine any position within the period length of the function. In the present invention, in the case of N-2, such a function can be performed.

A first transmitting electrode and a second receiving electrode having a rectangular or periodic shape simplifies the prediction of the shape and performance of the measurement system. Furthermore, it is possible to determine the eccentricity function D (x) without directly determining the voltage distribution of the electromagnetic pattern produced by the second transmitting electrodes corresponding to the excitation of at least one group of the first transmitting electrodes. Another example of a way to take into account the eccentricity function is by at least two exchange functions for the signals between the first or second transmit string across the first receive electrode or the second transmit electrode. If the shape and relationship between the exchange functions with respect to the measurement direction are known, the measurement position can be derived from the measurement of the exchange functions. The possibility of the measurement transducer according to the invention for performing fine and coarse/medium composite measurements using the same electrode set derives from the lack of constraints on the shape of the first receiving electrode array for coarse composite measurements. The first receiving electrode row has periodicity, and the shape of the electrodes meets the requirements for close-sight composite measurement.

The first receiving electrode array is thus given a pitch Pr4 and an electrode pitch, and the combination of the first transmitting electrode shape makes the electrode shape have a wavelength V'' of the signal transmitted from the first transmitting electrode to the first receiving electrode. provides a periodic exchange function.The pitch Prl is equal to the dense wavelength V', and the electrode smaller than wr (preferably Wf72 or less) is preferably one of the first transmitting electrodes with a width not greater than WCl2. to provide the desired periodic exchange function for the transducer.The first transmitter electrodes are spaced at an integer multiple of the wavelength V and are coupled together to produce a more powerful transducer output signal. It is also possible that the first receiving electrodes located at intervals that are an integral multiple of the wavelength vr, which is a combination of the first transmitting electrodes located at equal intervals equal to the wavelength wr, have the same exchange function.The first transmitting electrodes may have the same exchange function. Some combinations of irregular arrangements of electrodes and first receiving electrodes can also obtain the desired exchange function.However, all embodiments of first transmitting electrodes and first receiving electrodes are connected to a common reference point. It should be located at a location corresponding to an integral multiple of the wavelength V'.

[Additional notes] 1. The measuring device according to claim 1 comprises second receiving electrode means arranged on the first support member along the corresponding first row of transmitting electrodes for sensing the deflection of the electrodes. .

2. In the measuring device according to Supplementary Note 1, the first transmitting electrode has a predetermined spacing with respect to the measurement axis, each defined by at least two adjacent first transmitting electrodes, and the second transmitting electrode The receiving electrode electrode means has at least one elongated second receiving electrode having a shape variable relative to the measuring axis, corresponding to the measuring axis distance spanned by each group of first transmitting electrodes.

3. In the measuring device described in Supplementary Note 2, the first transmitting electrodes have a uniform predetermined interval with a pitch Ptl, at least one first transmitting electrode group defines a transmitting wavelength Wtl, and at least one first transmitting electrode group defines a transmitting wavelength Wtl. 2 receiving electrodes have a shape that changes periodically with respect to a receiving wavelength Wr2 that has a predetermined relationship with respect to the transmitting wavelength Wt1.

4. In the IIN determination in Supplementary Note 3, at least one second receiving electrode spans an integral multiple of the transmission wavelength Wtl, without making any concessions.

5. In the measurement described in Supplementary Note 3, the first receiving electrodes each have a predetermined interval by a pitch Prl defined by the scale wavelength Wf.

6. In the measuring device according to Supplementary Note 5, the second transmitting electrodes are uniformly spaced from each other by a pitch Pt2 different from the pitch Prl, so that
The change in the deflection of the transmitting electrode becomes a linear function at each position of the second transmitting electrode with respect to the reference position, and
The relationship is 2-Wtl (Pt 2/P r 1).

7. In the measuring device according to Supplementary Note 3, the shape of the second receiving electrode is substantially a sine waveform.

8. In the measuring device according to Supplementary Note 3, the shape of the second receiving electrode is substantially triangular.

9. In the measuring device according to Supplementary Note 3, the shape of the second receiving electrode is substantially rectangular.

10. In the measuring device described in Supplementary Note 2, the first
The transmitting electrodes have a uniform predetermined function of pitch Ptl, at least one said first transmitting electrode group defines a transmitting wavelength Wtl, said second receiving electrode means individually separate extensions of second receiving electrodes. The pitch of adjacent pairs of second receiving electrodes defines a receiving wavelength Wr2 having a predetermined relationship with respect to the transmitting wavelength Wtl.

11. In a capacitive measuring device, the first and second supporting members can be arranged opposite to each other, and the at least one supporting member can be arranged relative to the measuring axis, and the supporting members can be arranged relative to each other, and the supporting members can be arranged relative to the measuring axis. A first transmitting electrode row is arranged on the first support member along the measurement axis, a first receiving electrode row is arranged on the second support member along the measurement axis, and the different members of the first receiving electrode row are arranged on the first support member along the measurement axis. a first transmitting electrode row located on a relative position of the support member, a second transmitting electrode row disposed along the first transmitting electrode row on the corresponding second support member; One group of receiving electrodes has at least one corresponding second
each second transmitting electrode of at least one second transmitting electrode group is electrically coupled to a corresponding one of said first receiving electrodes, and each second transmitting electrode of at least one second transmitting electrode group is electrically coupled to a corresponding one of said first receiving electrodes; The second transmitting electrode is decentered with respect to the receiving electrode by a predetermined number of times the position of the second transmitting electrode corresponding to the center of one group.

12. The capacitive measuring device includes first and second support members, the support members are replaceable relative to each other, and at least one support member is replaceable relative to the measurement axis;
At least one first receiving electrode array is disposed on a second support member along the measurement axis, and with the concession that different members of the at least one first receiving electrode array are located on the first support member at relative positions on the support member. a second electrode row on a second support member connected to the transmitting electrode row and disposed relatively along the second receiving electrode row, each of the second transmitting electrodes being connected to a corresponding one of the first receiving electrodes; The second transmitting electrode is electrically connected to the corresponding first receiving electrode so as to be eccentric in accordance with the value of a predetermined function at the position of the second transmitting electrode with respect to the reference point on the measurement axis, and between the second transmitting electrode and the first receiving electrode. The degree of deflection of the electrodes varies by a predetermined amount, the space occupied by the second transmitting electrodes is defined as a first measuring range, and the second supporting member is arranged along at least one row of the corresponding first receiving electrodes. the second transmitting electrode row and at least one group of first receiving electrodes are electrically coupled to the corresponding at least one group of third transmitting electrodes;
Without compromise, each third transmitting electrode of a group of third transmitting electrodes is electrically coupled to a group of said first receiving electrodes, with at least one of the second transmitting electrodes relative to the center of one group of second transmitting electrodes. eccentric with respect to the corresponding first receiving electrode by a predetermined function value depending on the relative position;
As a result, the degree of electrode deviation changes according to a predetermined value across the groups of the second transmitting electrodes, and the number range occupied by at least one second transmitting electrode group is closer to the second measurement range than the second measurement range. Defined by

13. The measuring device according to Supplementary Note 11 further includes second receiving electrode means disposed in the form of a first indicating member along the opposing row of transmitting electrodes in order to sense the deflection of the electrodes.

14. Supplementary Note 12 The measuring device further comprises a second transmitting electrode, a second receiving electrode arranged on the first support element along the first transmitting electrode row, and at least one group of second transmitting electrodes. and a third receiving electrode disposed along the corresponding first transmitting electrode row in the shape of the third indicator element to sense an electrode deviation between the third transmitting electrode and the corresponding first receiving electrode.

15. In the measurement apparatus according to Supplementary Note 14, the first transmitting electrodes have a predetermined spacing of pitch Ptl with respect to the measurement axis, and at least one group of first transmitting electrodes is at least two adjacent transmitting electrodes. Defined by, without concession, at least one first transmitting electrode group is defined by the transmitting wavelength Wtl, the first receiving electrodes are evenly spaced from each other according to a pitch P'1 defined by the scale waveform Wf, and the electrodes are The predetermined amount of deviation is substantially equal to the second transmission wavelength Wtl.

16. In the measuring device of Supplementary Note 15, at least the third transmitting electrodes in the second transmitting electrode group are spaced apart from each other by a uniform pitch Pr3 different from the pitch Prl.

17. In the measuring device of Supplementary Note 16, the pitch P"3 is larger than the pitch Prl.

18. Supplementary Note 16 In the measuring device, the pitch P"3 is smaller than the pitch Prl.

19. In the measuring device according to claim 1, the first receiving electrodes are spaced apart from each other in the measurement axis direction at a pitch Prl defined by the scale wavelength Wf, and at least one group of the first transmitting electrodes is It can be defined by N adjacent electrodes, and N is twice or more individually. Without compromise, at least one group of transmitting electrodes is fixed at the transmitting wavelength, and the first transmitting electrodes of each group - have positions within the group such that they occupy predetermined group positions with respect to each other over a distance greater than the positional wavelength; , by the transmission wavelength Wt of the corresponding dense wavelength, and dividing the segment into N equal intervals, so that each group position corresponds to one different corresponding position of the group of corresponding dense wavelength segment positions. .

20. In the measuring device of Supplementary Note 12, the first receiving electrodes are spaced apart from each other in the measurement axis direction at a pitch Prl defined by the scale wavelength Wf, and at least one group of the first transmitting electrodes is arranged at intervals between adjacent electrodes. It can be defined in N pieces, where N is 2 or more.

Without compromise, at least one group of transmitting electrodes is fixed at the transmitting wavelength, and the first transmitting electrodes of each group - have positions within the group such that they occupy predetermined group positions with respect to each other over a distance greater than the positional wavelength; , divided by the transmission wavelength Wt of the corresponding dense wavelength, and equalizing the segments N
By dividing into intervals, each group position corresponds to one different corresponding position of the corresponding group of dense wavelength segment positions.

21. The measuring device of Supplementary Note 19 further provides that the first stage connection according to the successive positions of the first transmitting electrodes of each first transmitting electrode group loop is arranged at the position of the first transmitting electrode group. The second stage coupling according to the continuum for the dense wavelength segments is approximately N for each electrode of each first transmitting electrode group.
Excitation signal means selectable to generate a periodic variable excitation signal.

22. In the measuring device of Supplementary Note 21, the N signal is different for each increment and is connected in numerical order with the corresponding first transmitting electrode in each first transmitting electrode group in the first stage of the series, The second row of connections is different from the second stage connections.

23. The measuring device according to appendix 21, wherein the second receiving electrode means produces first and second outputs complementary to the excitation signal oscillated to the second transmitting electrode, and the measuring device selectively produce a second and second output, and optionally combine the second and second outputs, and if the second received output had the shape of an elongated invariant plate, It has signal processing means for outputting a measurement signal equal to the signal.

24. In a capacitance type measuring device, the first and second reception members and the support member are movable with respect to each other, and each signal transmission path has a capacitance exchange function that is variable depending on the relative position of the first and second indicating members. the second-second axis for the measurement axis to provide
means for generating N groups of N excitation signals having a value in multiples of 4, comprising an electrode array located on the indicator member, said group loop of example signals continuously comprising phase shifts of different combinations of signals; , a first set of a group of exemplary signals for the electrode array successively producing a first second electrode array means output signal, a second
means for selectively generating a second demodulated signal; a means for selectively generating a second demodulated signal; a means for selectively generating a second demodulated signal; The signal is multiplied by an integer by the integrator means until the integrator output returns to the reference level, the first and second demodulated signals of the group of excitation signals being multiples of the second demodulated signal output. The corresponding means of the output of the integration time measuring means, selected to be an integer of the output of the integrating machine in the opposite direction, is the demodulator and f
fi resetting the multi-ramp integrator means so that the first and second sets of groups of different excitation signals are continuously generated on the electrode array until no output is produced during said integral measurement time. A demodulation and overlapping ramp integration means is triggered to integrate the result after two demodulations.

25. In the measuring device according to Supplementary Note 24, the excitation signal is a variable periodic signal having a predetermined frequency, each group of excitation includes two sets of signals that are each inverted, and each group of excitation signals The opposing sets of excitation signals in are continuously incrementally changed by one excitation signal from one group to the next excitation signal.

26. In the measuring device of appendix 25, the output signal of the electrode array means is substantially sinusoidal, the first and second Nigel loops of the excitation signal are selected to be in square phase with respect to each other, and the second demodulation The predetermined limit value per integration time of the signal corresponds to the range over which the ratio of the output signals of the first and second electrode array means lies substantially on a line.

17. In the measuring device according to Supplementary Note 25, in the capacitive measuring device, a first and second supporting member, the supporting member is movable with respect to each other, and an individual having a capacitive conversion function with respect to the first and second components. An array of electrodes is disposed on the first and second indicating members relative to the measurement axis to provide a signal transmission path for the first and second points.
The component varies depending on the position of the associated signal transmission path with respect to a reference transition on one pointing member, and the second component varies according to a predetermined function over a predetermined wavelength.

28. In the measuring device of Supplementary Note 27, the first conversion function component varies linearly, and the predetermined function of the second conversion function component is periodic.

2. In paragraph 28, the bag further comprises filter means for selectively sensing changes in the output signal produced by the electrode array relative to the oscillated excitation signal due to either the first or second conversion component. have

30, in the measuring device of Supplementary Note 129, the means includes a detector electrode means including an electrode, and the detector electrode means generates first and second outputs separately from each other, and the detector electrode means generates first and second outputs separately from each other, and The resulting signal becomes a signal that varies according to the second conversion function element.

31. The device according to appendix 30, wherein the sensing electrode means comprises first and second supplementary elongated electrode elements having a contour deformed according to a predetermined function with respect to the measuring axis.

32. In the measuring device according to appendix 31, the sensing electrode means comprises first and second supplementary elongated electrode elements having a shape that deforms according to a predetermined function with respect to the measuring axis.

[Brief explanation of drawings]

FIG. 1 is a partial schematic diagram of a first embodiment of the absolute measurement type calibus of the present invention, including a partial block diagram. FIG. 2A is a top view of essential parts of a transducer according to a second embodiment of the present invention. FIG. 2B is a top view of a main part showing another part of the transducer shown in FIG. 2A. FIG. 3 is a perspective view of essential parts of a second embodiment of the present invention. FIG. 4 is a block diagram of main parts showing another embodiment of the absolute measurement method Calibus according to the present invention. FIG. 5 is a schematic block diagram illustrating an exemplary embodiment of a Calibus measurement circuit diagram according to the present invention. FIG. 6 is a table showing the relationship of control signals for a transducer excitation signal generator including the measurement circuit of FIG. FIG. 7 is a table showing the relationship between control signals of a transducer output combiner including the measurement circuit shown in FIG. 8A-8E are flowcharts showing a program executed by a microprocessor including the control circuit of FIG. FIG. 9 is a graph showing the positional relationship of the transducer outputs generated in response to the combined excitation signals of each phase generated by the measurement circuit of FIG. 5 with respect to the measurement axis.

Claims (1)

[Claims] In a capacitive measuring device, the measuring device includes first and second support members, the support members are movable relative to each other, and at least one support member is movable relative to the measurement axis; A first transmitting electrode array is disposed on the first support member along the measurement axis, a first receiving electrode array is disposed on the second support member along the measurement axis, and different a second row of electrodes on a second support member, the second row of electrodes being coupled to a first row of transmitting electrodes on a relative position of the support member; Each of the transmitting electrodes is connected to one of the corresponding first receiving electrodes so as to be eccentric with respect to the electrically corresponding first receiving electrode by a value of a predetermined function at the position of the second transmitting electrode with respect to the reference point on the measurement axis. A capacitive position measuring device for absolute measurement including the above member.