CN110785633A - Encoder for encoding a video signal - Google Patents

Abstract

The encoder 10 is provided with: M sensors 31 to 34, which detect a plurality of components representing angles arranged on the base at predetermined angular intervals to generate a periodic first signal, the M sensors are arranged at a predetermined angle, and the predetermined angle is the angle formed by 360/M×(j‑1)(degree) and 360/N×MOD[(k _j ‑1)/D](degree), where M is an integer greater than 2, and N is the number of components , MOD is a function that outputs the value below the decimal point of the input value, D is a factor of M or M but not 1, j is an integer from 1 to M to take different values from M sensors, k _j is an integer from 1 to M; generators 41 to 44, for each of the M sensors, generate a second signal based on the first signal, the second signal interpolates a predetermined angular interval; and an operator 50, for M The second signals of the two sensors are combined and calculated to obtain an angular position or a rotation angle.

Description

Encoder

technical field

The present invention relates to an encoder for detecting position and angle.

Background technique

An encoder is a device for measuring positions such as a rotation angle and an absolute angular position by reading scales engraved at equal angular intervals on a dial. The interval of the scale is limited according to the precision of the marking or the precision of the sensor that detects the scale, so the improvement of the resolution caused by the scale is also limited. Therefore, two analog signals whose phases are shifted by 90 degrees are generated from sine waves further divided by the minimum scale interval, arctan operation is performed on the two analog signals, and the angle is determined using the interpolation signal representing the angle, and the resolution is promote.

Furthermore, in order to reduce the scribing error of the scale, the installation error of the encoder, and the like, a method of arranging a plurality of sensors and averaging the interpolated signals obtained from the respective sensors is used. Furthermore, there has been proposed a method of further providing a sensor for correction to perform self-correction of the angle error (for example, refer to Patent Document 1).

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2011-99804

SUMMARY OF THE INVENTION

[Problems to be Solved by Invention]

An object of the present invention is to provide a novel and useful encoder capable of achieving both high resolution and high precision.

According to an aspect of the present invention, an encoder is provided, comprising: M sensors for detecting a plurality of components representing an angle and arranged on a base at a predetermined angular interval to generate a first signal with periodicity, the M sensors The sensor is configured at a predetermined angle, and the predetermined angle is an angle formed by 360/M×(j-1)(degree) and 360/N×MOD[(k _j -1)/D](degree), where M is an integer of 2 or more, N is the number of components, MOD is a function that outputs the value below the decimal point of the input value, D is a factor of M or M but not 1, and j is an integer from 1 to M consisting of M Each of the sensors takes different values, and k _j is an integer from 1 to M; the generator, for each of the M sensors, generates a second signal based on the first signal, the second signal signal interpolation at the predetermined angular interval; and an arithmetic unit for obtaining an angular position or a rotation angle by combining and computing the second signals for the M sensors.

According to the above aspect, by arranging the M sensors with respect to the base in which the plurality of components representing the angles are arranged at predetermined angular intervals, the distances between 360/M×(j−1) (degrees) and 360/N×MOD[(k _j -1)/D] (degrees), an encoder capable of interpolating the angle error of the second signal generated based on the first signal generated by the sensor and interpolating the second signal at the predetermined angular interval. The angular error of the encoder can be reduced, and the angular error of the encoder can also be reduced due to the error due to the eccentricity caused by the attachment to the rotation shaft of the base and the error of the formation position of a plurality of components arranged at equal angular intervals. , as a result, an encoder with both high resolution and high precision can be provided.

According to another aspect of the present invention, there is provided an encoder comprising: M sensors for generating a periodic first signal by detecting a plurality of components representing positions and arranged on a base at predetermined intervals, the M sensors The sensors are arranged at a predetermined distance from each other, and the predetermined distance is a combination of gl×m _j and gl×MOD[(k _j -1)/D] which is an integer (m _j ) multiple of the predetermined interval (gl) position, where M is an integer greater than or equal to 2, MOD is a function that outputs the value below the decimal point of the input value, D is a factor of M or M but not 1, and k _j is an integer from 1 to M; the generator, for each of the M sensors, generating, based on the first signal, a second signal interpolating between components of the predetermined interval; and an operator, for the second of the M sensors The position or movement amount is obtained by combining the signals.

According to the above aspect, by arranging the M sensors at the predetermined interval (gl) with respect to the base in which the plurality of components representing the positions are arranged at an integer (m _j ) multiple of the predetermined interval (gl), gl×m _j and gl×MOD [(k _j -1)/D] combined position, the position error of the encoder caused by the position error of the second signal generated based on the first signal generated by the sensor and the interpolation of the second signal at the predetermined interval can be calculated. It is also possible to reduce the error of the encoder due to the position error caused by the attachment of the object to the base and the error of the formation position of the plurality of components arranged at a predetermined interval. As a result, it is possible to provide both high resolution. high-speed and high-precision encoder.

Description of drawings

[ Fig. 1] Fig. 1 is a diagram showing an angle error of a rotary encoder.

[ Fig. 2] Fig. 2 is a diagram showing discrete Fourier transform (DFT) analysis of the angle error shown in Fig. 1 of the rotary encoder.

[ Fig. 3] Fig. 3 is a diagram showing an angular error of an interpolation signal included in Fig. 1 of the rotary encoder.

[ Fig. 4] Fig. 4 is a diagram showing a schematic configuration of an encoder according to the first embodiment of the present invention.

[ Fig. 5] Fig. 5 is a diagram showing an arrangement position of sensors of the encoder according to the first embodiment of the present invention.

[ Fig. 6] Fig. 6 is a diagram showing an example of an arrangement position of each sensor in the first embodiment of the present invention.

[ Fig. 7] Fig. 7 is a diagram showing an angular error of an interpolation signal of the encoder according to the first embodiment of the present invention.

[ Fig. 8] Fig. 8 is a diagram showing an angular error of the encoder according to the first embodiment of the present invention.

[ Fig. 9] Fig. 9 is a diagram showing DFT analysis of the angle error of the encoder according to the first embodiment of the present invention.

10 is a diagram showing a schematic configuration of an encoder according to a second embodiment of the present invention.

[ Fig. 11] Fig. 11 is a diagram showing an example of an arrangement position of each sensor in the second embodiment of the present invention.

Detailed ways

The inventors of the present invention conducted studies in order to achieve high resolution and high precision of the rotary encoder, faced the problems described below, and found a solution to the problem.

Among the rotary encoders, a sensor reads a scale with a scale covering 360 degrees, generates a sine wave and a cosine wave based on the scale, and generates a signal between the interpolation scales (hereinafter referred to as an interpolated signal). Then, an angle signal is generated based on the interpolated signal, and the present angle or rotation angle is detected from the angle signal. When a plurality of sensors are provided, the angle is obtained by averaging the angle signals from the respective sensors. The interpolation signal is used to detect an angle smaller than the minimum scale, in other words, to increase the resolution.

The rotary encoder can reduce the eccentricity error of the rotary encoder and the angular position error of each scale of the scale by arranging a plurality of sensors on the scale at equal angular intervals and averaging the plurality of output angle signals. However, once the angle error of the rotary encoder is investigated, the angle error still remains, which becomes an obstacle to high precision. The present inventors investigated the angle error of a rotary encoder in which four sensors are arranged at equal angular intervals of 90 degrees. The number N of scales on the dial is 360, in other words, they are provided at equal intervals at intervals of 1 degree, and are multiplied by 32 integers by interpolating the signal. According to the rotation of the dial, the four sensors detect the signal including the basic scale and the angle error generated by the division by interpolation.

FIG. 1 is a diagram showing an angle error of a rotary encoder, which is an angle error when angle signals from four sensors are averaged. Referring to FIG. 1 , it can be seen that, covering 360 degrees (one circle), the angle error has a maximum of ±30 seconds.

FIG. 2 is a diagram showing discrete Fourier transform (DFT) analysis of the angle error shown in FIG. 1 of the rotary encoder.

Referring to FIG. 2 , it can be seen that the low-order portion is small, which is effective in reducing the eccentricity error and the angular error of the scale. However, the angle errors of the 360th, 720th, 1080th, 1440th, and 1800th order parts are large, ranging from 2 seconds to 11 seconds. For these angular error portions, the number of sensors M is 4 and the number of scales N is 360, the number of sensors M becomes a factor of the number of scales 360, and angle errors of multiples of the number of scales are generated as angular errors of the interpolated signal. For example, if the number of sensors is not 4, but even if it is 3, 5, or 6, the angle error of the interpolated signal will be generated in the same way because it is a factor of 360 of the number of scales.

As one method of reducing the angular error of such an interpolation signal, the number of sensors may be 7 or 13 arranged at equal angular intervals. 7 is not a factor of 360 for the number of ticks, so the angular error of the interpolated signal can be reduced.

FIG. 3 is a diagram showing the angular error of the interpolation signal included in FIG. 1 of the rotary encoder for each sensor. Figure 3 shows only the angle error of the interpolated signal from the angle error and is represented by each sensor. The horizontal axis is the angle (degrees), the vertical axis is the angle error (seconds), and the position of the black triangle (▲) represents the dial the position of the scale.

Referring to FIG. 3 , it can be seen that the waveforms of the angle errors of the sensors 1 to 4 are almost the same, and the phases are also almost the same. Accordingly, even if the angle signals of the sensors 1 to 4 are averaged, the angle errors of the sensors 1 to 4 cannot cancel each other, and as shown in FIG. 2 , the angle errors of the interpolated signals remain.

Accordingly, an object of the present invention is to provide an encoder with both high resolution and high precision which reduces the angle error of the interpolation signal by shifting the positions of the plurality of sensors from each other by adjusting the scale of the dial.

Hereinafter, an embodiment of the present invention will be described based on the drawings. In addition, the same code|symbol is attached|subjected to the component which is common among several drawings, and the repeated detailed description of the component is abbreviate|omitted.

[First Embodiment]

FIG. 4 is a diagram showing a schematic configuration of an encoder according to the first embodiment of the present invention.

Referring to FIG. 4 , the encoder 10 according to the first embodiment includes a dial 20 having scales 21 arranged on the rotation shaft 15 to be measured in the angle and formed at equal intervals in the circumferential direction, detection scales 21 , and based on the detection The four sensors 31 to 34 that generate detection signals of sine waves whose phases are periodically shifted by 90 degrees from each other, and the interpolated signals (also referred to as the interpolated signals at intervals of the scale) based on the detection signals of the respective sensors 31 to 34 Interpolation signal generators 41 to 44 for generating angle signals), and calculator 50 for calculating the angular position or rotation angle by combining and calculating the interpolated signals for each of the sensors 31 to 34 based on the interpolation signals.

The dial 20 is installed concentrically with the rotating shaft 15, and is provided with scales 21 at equal intervals in the circumferential direction, and the portion of the scale 21 allows light to pass therethrough.

Each of the sensors 31 to 34 has a light-emitting element 35 , a slit 36 and a light-receiving element 37 . In FIG. 4 , the details of the constituent elements of the sensors 32 to 34 are omitted and described, but the sensors 32 to 34 have the same constituent elements as the sensor 31 . The light emitted by the light-emitting elements 35 of the sensors 31 to 34 passes through the scale 21 and passes through the slit 36 to be received by the light-receiving element 37 . The light-receiving elements 37 of the sensors 31 to 34 generate electric signals of sine waves whose phases are shifted by 90 degrees from each other according to the intensity of the received light, and output them as detection signals. Two electrical signals of sine waves whose phases are shifted by 90 degrees from each other, for example, one is a Sin voltage signal, and the other is a Cos voltage signal.

The input parts of the interpolation signal generators 41 to 44 are electrically connected to the output parts of the sensors 31 to 34 , and generate interpolation signals based on the input detection signals. Specifically, the interpolation signal is generated by obtaining the angle from the arctan (voltage value of the Sin voltage signal/voltage value of the Cos voltage signal) of the Sin voltage signal and the Cos voltage signal of the detection signal. The interpolated signal is a digital signal. The interpolation signal is a signal in which the scale interval is divided at equal intervals, for example, a signal of several tens of integer multiples to several hundreds of integer multiples.

The arithmetic unit 50 is electrically connected to the output parts of the interpolation signal generators 41 to 44 , respectively, and combines and calculates the interpolation signals from the interpolation signal generators 41 to 44 . Specifically, for example, the angular position or the rotation angle is obtained by counting the pulses of the interpolation signal generated by the rotation of the rotary shaft 15, combining the obtained pulse numbers, and dividing the result by the number of sensors. The arithmetic unit 50 can cancel the angle errors of the interpolation signals of the interpolation signal generators 41 to 44 by combining operations, thereby reducing the angle errors and improving the precision.

FIG. 5 is a diagram showing an arrangement position of sensors of the encoder according to the first embodiment of the present invention.

的位置。角度的基点能够任意选择，但是例如能够选择传感器31的位置。角度

以算式1表示，θ_j(度)以算式2表示，δ_k以算式3表示。Referring to FIG. 5 , the detection positions of the sensors 31 to 34 are arranged at an angle relative to the dial 20 of

s position. The base point of the angle can be arbitrarily selected, but for example, the position of the sensor 31 can be selected. angle

It is represented by Formula 1, θ _j (degree) is represented by Formula 2, and δ _k is represented by Formula 3.

θ _j =360/M×(j-1), (j=1,2,...,M)...(2)

δ _kj =360/N×MOD[(k _j -1)/D](k _j =1,2,...,M)...(3)

Here, j is an integer of 1 to M allocated to the sensors 31 to 34 . D is a factor of M or is M (but not 1). M is the number of sensors, which is four in the first embodiment. N is the number of graduations 21 covering 360 degrees of the dial 20, and is 360 in the first embodiment.

The MOD of the above-mentioned formula 3 is a function to output the value below the decimal point of the input value. MOD[(k _j -1)/D] is a value (decimal) smaller than 1, for example, MOD[3.75]=0.75, MOD[1.25]=0.25, and MOD[0.25]=0.25. As a result, δ _kj becomes smaller than 360/N (degrees), in other words, smaller than the minimum scale interval.

亦可。亦即，算式1只要为组合算式2的θ_j与算式3的δ_kj的角度即可。In addition, as a modification of the above formula 1, it is

You can also. That is, Equation 1 only needs to be an angle combining θ _j of Equation 2 and δ _kj of Equation 3.

In FIG. 5 , four sensors 31 to 34 are arranged. This is the case where D=M=4 in the equations 1 to 3. The sensors 31 to 34 are respectively arranged at the angle Among them, k _j=1～4 =1,2,...,4. In addition, the apex of the dial facing the triangular mark Δ indicates the detection position of the sensor.

FIG. 6 is a diagram showing an example of the arrangement position of each sensor in the first embodiment of the present invention, and the arrangement position of each sensor shown in FIG. 5 is enlarged and shown. (a) to (d) of FIG. 6 show the arrangement positions of the sensors 31 to 34, respectively.

(j＝1～4的整数)的角度的位置。θ_j为360度经四等分的角度位置，δ_kj为将刻度21的最小角度间隔经四等分的角度作为单位的角度。刻度数量N＝360的场合，传感器31～34分别配置在例如以下

及(4,k₄)所表示的角度。Referring to (a) to (d) of FIG. 6 , the sensors 31 to 34 are arranged in

(j=integer of 1 to 4) is the position of the angle. θ _j is an angular position divided into quarters by 360 degrees, and δ _kj is an angle whose unit is an angle at which the minimum angular interval of the scale 21 is divided into quarters. When the number of scales is N = 360, the sensors 31 to 34 are respectively arranged as follows, for example

and the angle represented by (4,k ₄ ).

Sensor 31:

Sensor 32:

Sensor 33:

Sensor 34:

FIG. 7 is a diagram showing an angle error of an interpolation signal of the encoder according to the first embodiment of the present invention. Referring to FIG. 7 , the waveforms of the angle errors of the interpolation signals of the sensors 11 to 14 are each shifted in phase by 1/4 degree (0.25 degrees), reflecting the δ _kj of the arrangement of the sensors 31 to 34 .

FIG. 8 is a diagram showing an angular error of the encoder according to the first embodiment of the present invention.

Referring to FIG. 8 , it can be seen that the angle error of the encoder is ±16 seconds at the maximum, which is about 1/2 of the angle error shown in FIG. 1 previously.

FIG. 9 is a diagram showing DFT analysis of the angle error of the encoder according to the first embodiment of the present invention, in which the angle error of FIG. 8 is subjected to DFT analysis.

Referring to FIG. 9 , it can be seen that the angular errors of the 360th, 720th, 1080th, and 1800th order parts, which are multiples of the number of scales 360, are less than 2 seconds. In particular, the 360th order part is reduced to 6% compared with FIG. 2, and the 720th order part is reduced to 6%. reduced to 9%. This clearly shows the effect of the present embodiment.

As a modification example (modification example 1) of the arrangement positions of the sensors 31 to 34 , δ _kj of the above-mentioned formula 1 can take values of 0, 0.25, 0.50, and 0.75 according to the formula 3, and can be arbitrarily allocated to the sensors 31 to 34 . For example: (δ _k1 ,δ _k2 ,δ _k3 ,δ _k4 )=(0,0.50,0.25,0.75), (0,0.75,0.25,0.50), (0.25,0,0.50,0.75) and so on. It is understood from the principle of the present invention that the effects of the present embodiment described above can be similarly obtained by this modification example.

In addition, as another modification example (modification example 2) of the arrangement position of the sensors, θ _j of the formula 1 can be set to 0, 90, 180, and 270 according to the formula 2, and the sensors 31 to 34 are only shifted from the respective positions. However, in this case, the error of the low-order part will increase, so it is preferable to set θ _j at equal angular intervals.

Furthermore, as another modification example (modification example 3), when D of Equation 3 is a factor of M, each sensor in Equation 3 is one of the integers from k _j = 1 to M, and when the number of sensors is 4 In this case, when D is 2, (δ _k1 , δ _k2 , δ _k3 , δ _k4 )=(0, 0.5, 0, 0.5). In this case, among the angle errors of the encoder caused by the angle error of the interpolation signal, the error of the N times-order part (excluding the (N×D)-order part) can be reduced.

According to the present embodiment, the plurality of sensors 31 to 34 are arranged relative to the dial 20 at the right-hand term of Equation 2 360°/M×(j−1) and the right-hand term of Equation 3 360°/N×MOD[ The position of the angle combined by (k _j -1)/D] can be calculated by dividing the N-fold part (however, the (N×D-order part) from the angle error of the encoder due to the angle error of the interpolation signal. The error of the encoder is reduced, and the angle error of the encoder caused by the error due to the eccentricity caused by the attachment to the rotary shaft 15 of the dial 20 and the error of the formation position of the scale 21 of the dial 20 can also be reduced. Therefore, according to the present embodiment, it is possible to provide an encoder that achieves both high resolution and high precision.

In the present embodiment, an example of using a transmissive optical sensor is given. As an alternative example, a scale is used to indicate a scale, and a reflection-type optical sensor that optically compares the scale and other portions may be used. For example, it is a dial having a higher or lower reflectivity (in other words, higher absorptivity) of a portion of the scale than other portions.

The present embodiment can also be applied to a magnetic encoder provided with a magnetic sensor and a magnetic scale in place of the optical sensor and the dial. The plurality of magnetic sensors for detecting the magnetic scale may be arranged in the same manner as the optical sensors described above.

The encoder 10 of the present embodiment can be applied to an incremental encoder that detects the rotation angle or rotational speed of the rotary shaft 15 , and can be applied to an absolute encoder that detects an absolute angular position.

[Second Embodiment]

FIG. 10 is a diagram showing a schematic configuration of an encoder according to a second embodiment of the present invention.

Referring to FIG. 10 , an encoder 100 according to the second embodiment includes a measurement object (not shown) arranged at a position or a movement amount and formed at equal intervals in the moving direction of the object (direction indicated by arrow MV). The dial 120 of the scale 121, the three sensors 131 to 133 that detect the scale 121 and generate detection signals having periodic sine waves whose phases are shifted by 90 degrees from each other based on the detection, and the detection signals based on the respective sensors 131 to 133 On the other hand, interpolation signal generators 141 to 143 that generate interpolation signals at intervals of interpolation scales, and calculator 150 that combines and calculates the interpolation signals for each of the sensors 131 to 133 based on the interpolation signals to obtain the position or the amount of movement. .

The dial 120 is attached along the moving direction of the object (the direction indicated by the arrow MV), and the scales 121 are provided at equal intervals. The portion of the scale 121 can reflect light. In addition, the part of the scale 121 may absorb the light and the surface of the scale 120 around the scale 120 may reflect the light.

The sensors 131 to 133 each have a light-emitting element 135 and a light-receiving element 137 . The light emitted by the light emitting elements 135 of the sensors 131 to 133 is reflected through the scale 121 and received by the light receiving element 137 . The light-receiving elements 137 of the sensors 131 to 133 generate electric signals of sine waves whose phases are shifted by 90 degrees from each other according to the intensity of the received light, and output them as detection signals. Two electrical signals of sine waves whose phases are shifted by 90 degrees from each other, for example, one is a Sin voltage signal, and the other is a Cos voltage signal.

The interpolation signal generators 141 to 143 and the arithmetic unit 150 have the same structures and operations as the interpolation signal generators 41 to 44 and the arithmetic unit 50 in the first embodiment, respectively, and obtain the position or movement of the dial 120 . quantity. The arithmetic unit 150 can cancel the position errors of the interpolation signals of the interpolation signal generators 141 to 143, thereby reducing the position errors and improving the precision.

FIG. 11 is a diagram showing an example of an arrangement position of each sensor in the second embodiment of the present invention. (a) to (c) of FIG. 11 respectively show the arrangement positions of the sensors 131 to 133 .

11 , the detection positions of the sensors 131 to 133 are arranged at the position p(j, k _j ) with respect to the dial 120 . Although the reference point of the position can be arbitrarily selected, for example, the position of the sensor 131 can be selected. The position p is expressed by Equation 5, L _j is expressed in Equation 6, and δ _kj is expressed in Equation 7.

p(j,k _j )=L _j +δ _kj …(5)

L _j =gl×m _j ...(6)

δ _kj =gl×MOD[(k _j -1)/D](k _j =1,2,...,M)...(7)

Here, j is an integer of 1 to M allocated to the sensors 131 to 133 . m _j is an integer, and different integers are selected for j. D is a factor of M or is M (but not 1). gl is the tick interval. M is the number of sensors, which is three in the second embodiment. MOD is a function that outputs a value below the decimal point of the input value, and is the same as the first embodiment. In addition, as a modification of the above-mentioned formula 5, p(j, k _j )=L _j −δ _kj may be used. In other words, Equation 5 only needs to be a position where L _j of Equation 6 and δ _kj of Equation 7 are combined.

As shown in (a) to (c) of FIG. 11 , the sensors 131 to 133 are arranged at positions of p(j, k _j )=L _j +δ _kj (j=an integer of 1 to 3). L _j is an integer multiple (m _j times) of the scale interval gl, and δ _kj is the distance divided into three equal parts by the scale interval gl. The sensors 131 to 133 are arranged at positions indicated by p(1, k ₁ ), p(2, k ₂ ), and p(3, k ₃ ) below, respectively.

Sensor 131: p(1, k ₁ )=L ₁ +δ _k1 =0+0=0

Sensor 132: p( ₂ ,k2)=L2 _{+ δk2} =gl×10+gl×1/3=(10+1/3)×gl

Sensor 133: p(3, k ₃ )=L ₃ +δ _k3 =gl×20+gl×2/3=(20+2/3)×gl

The sensors 131 to 133 are arranged in such a way that the phases of the position errors of the interpolated signals are shifted from each other by 1/3 of the scale interval gl, and the interpolated signals for the sensors 131 to 133 are combined and calculated by the calculator 150, and the reduction caused by The error of the position error of the interpolated signal. As a result, the precision of the encoder 100 is improved.

As a modification example (modification example 4) of the arrangement positions of the sensors 131 to 133 , δ _kj of the formula 5 takes the values of 0, 1/3 and 2/3 according to the formula 7, but the sensors 131 to 133 may be arbitrarily allocated. . It is understood from the principle of the present invention that the effects of the present embodiment described above can be similarly obtained by this modification example.

According to the present embodiment, the plurality of sensors 131 to 133 are arranged relative to the dial 120 on the right-hand term gl×m _j of Equation 6 and the right-hand term gl×MOD[(k _j −1)/D] of Equation 7 The combined position can reduce the angular error of the encoder caused by the angular error of the interpolation signal, and can also reduce the error caused by the alignment of the object attached to the dial 120 and the dial 120 The position error of the encoder 100 is reduced by the formation of the position error of the scale 121 . Therefore, according to the present embodiment, it is possible to provide an encoder that achieves both high resolution and high precision.

In addition, in the present embodiment, transmissive sensors and dials can be used instead of the reflective sensors 131 to 133 and the dial 120 . Furthermore, this embodiment can be applied to a magnetic encoder.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the present invention described in the claims. For example, in the first embodiment and the second embodiment, the technical idea and modification examples described in one of the embodiments may be combined in the other embodiment.

Symbol Description

10, 100 encoder

20, 120 dial

21, 121 scale

31～34, 131～133 Sensors

41～44, 141～143 Interpolation signal generator

50, 150 calculator

Claims (8)

1. An encoder, comprising:

m sensors for detecting a plurality of elements arranged on a substrate at predetermined angular intervals and representing angles, and generating a first signal having periodicity, wherein the M sensors are arranged at predetermined angles, and the predetermined angles are 360/Mx (j-1) (degree) and 360/NxMOD [ (k) _j-1)/D](degree) wherein M is an integer of 2 or more, N is the number of elements, MOD is a function of an output of a value of a decimal point or less of an input value, D is a factor of M or M but not 1, j is a value different from each other for M of the sensors in an integer of 1 to M, k is _jIs an integer from 1 to M;

a generator that generates, for each of the M sensors, a second signal based on the first signal, the second signal interpolating the predetermined angular interval; and

and an arithmetic unit for calculating an angular position or a rotation angle by combining the second signals for the M sensors.

2. The encoder of claim 1, wherein the substrate is a disk-shaped scale, and the component arrangements are arranged in a circumferential direction.

3. An encoder, comprising:

m sensors for detecting a plurality of elements arranged on a substrate at predetermined intervals to generate a periodic first signal, wherein the M sensors are arranged at predetermined intervals from each other, and the predetermined intervals are integers (M) of the predetermined intervals (gl) _j) Multiple of gl × m _jAnd gl × MOD [ (k) _j-1)/D]The combined positions where M is an integer of 2 or more, MOD is a function of the output of values below the decimal point of the input value, D is a factor of M or is M but not 1, k _jIs an integer from 1 to M;

a generator that generates, for each of the M number of the sensors, a second signal between components interpolated at the predetermined intervals based on the first signal; and

and an arithmetic unit for calculating a position or a movement amount by combining the second signals for the M sensors.

4. The encoder according to claim 3, wherein a plurality of the components are arranged in the same direction on the base.

5. The encoder of any of claims 1 to 4, wherein said k is _jThe M sensors have different values.

6. The encoder of any one of claims 1 to 5, wherein the D is M.

7. The encoder of any one of claims 1 to 6, wherein the assembly is constituted by a slit for passing light, a member for reflecting light, or a member for absorbing light, and a plurality of the sensors are optical sensors.

8. The encoder according to any one of claims 1 to 6, wherein the component is a convex member or a magnet member made of a ferromagnetic body, and the plurality of sensors are proximity sensors that magnetically detect the convex member or the magnet member.

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