JP2006343110A - Absolute position detection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect absolute positions with high accuracy and high resolution in position detection, while reducing the number of stages of a scale provided for a scale member, reduce the size and the weight of an apparatus itself, and being able to effective mount to a narrow space. <P>SOLUTION: This absolute position detection apparatus specifies as absolute positions the positions of arrangement of a first detection part and non-detection parts 5a and 5b in a first-stage scale 5, which face first detection members 11a and 11b, on the basis of the amount of displacement of detections signals from second detection members 13a and 13b to detection signals to the first detection member 11a and the first light reception member 11b. A second count means 35b counts the arrangement number of the specified first detection part and the specified non-detection parts 5a and 5b. The count value by a first counting means 35a is added to a value, acquired by multiplying a count value of the second counting means 35b by the pitch of the first detection part and the non-detection parts 5a and 5b and detected as absolute position. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an absolute position detection device that detects a moving position of a moving body as an absolute position when the moving body is moved by closed loop control of a servo motor.

  As position detection devices for controlling the movement of a moving body by performing closed loop control of a servo motor, optical or magnetic linear encoders, rotary encoders, and the like are known. In order to detect the moving position of the moving body as an absolute position by the position detection device in this way, a number of scales made up of, for example, a detection unit and a non-detection unit with a pitch of 1 mm are provided on the first stage of the scale plate and the second stage. A scale with double pitch of the first scale and a scale with double pitch of the previous scale are provided in order on the third stage, and the absolute position is detected by sequentially identifying the scale position on the lower stage with the upper scale. I can do it.

However, if the scale of the first stage is 1 mm pitch, the detection resolution is 1 μm, and the detection distance is 1000 mm, it is necessary to divide it into 1 million. Since the structure of the scale plate is complicated or increased in size and requires a number of detection members according to the number of stages, the apparatus itself is increased in size and weight, resulting in high cost. Have the problem of becoming In particular, when the position detection resolution is 0.001 μm and the detection distance is 1000 mm, the scale plate needs to have a 30-stage scale, which makes the above-described drawbacks conspicuous and makes it difficult to install in a narrow space. Have the problem.
JP-A

  The problem to be solved is that the structure of the scale member is complicated and enlarged by forming a large number of scales on the scale member in accordance with the detection resolution and providing a detector for each scale. This increases the size and weight of the device itself, and makes it difficult to mount it in a narrow space.

  According to the first aspect of the present invention, the first scale of at least the first detectors arranged at a desired pitch and the first scale of the first scale and the first scale of the first scale have a pitch that matches every desired number. A second-stage scale in which a plurality of second graduations comprising at least a second detection unit are arranged in parallel to each other, and a first-stage and second-stage scale provided to move relative to the scale member. At least first and second detection members that respectively output electrical signals based on the respective scales, and a dividing unit that divides the first detection signals from the first detection members by a number corresponding to a desired position detection resolution, First counting means for counting the number of divided first detection signals, second counting means for detecting the displacement of the second detection signal relative to the first detection signal and counting the number of displacements, and the count value of the second counting means Between the first graduations The value obtained by multiplying the release by adding a count value by the first counting means comprising a computing means for detecting the absolute position.

According to a second aspect of the present invention, the first scale and the first scale in which a large number of first scales each including at least a first detection unit are arranged at a desired pitch, and at least the first pitch corresponding to the predetermined number of the first scales. A second stage scale and a second scale in which a large number of second scales composed of two detectors are arranged, and a plurality of third scales composed of at least a third detector are displaced by a predetermined amount for each predetermined number of the second scales. A scale member provided in parallel with each other and a scale member arranged in parallel with each other, and an electrical signal based on the scales of the first to third stage scales provided to move relative to the scale member. At least first to third detection members that respectively output, a dividing unit that divides a first detection signal from the first detection member by a number corresponding to a desired position detection resolution, and a first detection that is output and divided Number of signals First counting means for counting, second counting means for counting the number of displacements based on the displacement of the second detection signal from the second detection member relative to the first detection signal, and from the third detection member for the second detection signal Third counting means for counting the number of times the displacement of the third detection signal reaches a predetermined amount, and the distance between the sections of the second-stage scale to the number of sections of the second-stage scale specified by the count value of the third counting means A value obtained by multiplying the multiplied value and the count value of the second counting means by the distance between the first graduations, and a calculating means for detecting the absolute position by adding the distance between the first graduations based on the count values by the first counting means. .

According to a third aspect of the present invention, the first scale composed of at least the first detection section is arranged at a pitch corresponding to the desired position detection resolution, and the second scale composed of at least the second detection section includes the first scale. A scale member in which second stage scales arranged at a predetermined multiple pitch are provided in parallel with each other, and is provided so as to move relative to the scale member. Electricity is applied based on the scales of the first stage and second stage scales. At least first and second detection members that output signals, a dividing unit that divides the second detection signal from the second detection member by a number corresponding to a desired position detection resolution, and counts the number of first detection signals First counting means, second counting means for detecting the displacement of the second detection signal divided with respect to the first detection signal and counting the number of displacements, and the first graduation to the count value of the second counting means. First value multiplied by the distance between Comprising a computing means for detecting the absolute position by adding the count value by means.

According to a fourth aspect of the present invention, a first-stage scale in which a plurality of first scales including at least first detection units are arranged at a pitch corresponding to a desired position detection resolution, and a plurality of second scales including at least second detection units are first. With respect to the second-stage scale and the second scale arranged at a pitch that is a predetermined number times the scale, a large number of third scales composed of at least a third detection unit are arranged in such a manner that they are displaced by a predetermined amount for each predetermined number of second scales. A scale member provided with the third-stage scales parallel to each other, and provided so as to move relative to the scale member, and at least outputs electrical signals based on the respective scales of the first-stage to third-stage scales. First to third detection members; dividing means for dividing the second detection signal from the second detection member by a number corresponding to a desired position detection resolution; and first counting means for counting the number of first detection signals. , First Second counting means for detecting the displacement of the second detection signal divided with respect to the outgoing signal and counting the number of displacements, and the displacement of the third detection signal from the third detection member with respect to the second detection signal is a predetermined amount A third counting means for counting the number of times of the second counting means, a value obtained by multiplying the number of divisions of the second-stage scale specified by the count value of the third counting means by the distance between the divisions of the second-stage scale, and a total of the second counting means Computation means for detecting the absolute position by adding the value obtained by multiplying the numerical value by the distance between the first graduations and the distance between the first graduations based on the count value by the first counting means.

  The present invention can detect an absolute position with high accuracy with high position detection resolution while reducing the number of scale steps provided on the scale member. Further, the device itself can be reduced in size and weight, and can be effectively attached to a narrow space.

  The best mode of the present invention is to detect at least the absolute position by adding the count value of the first counting means to the value obtained by multiplying the count value of the second counting means by the distance between the first graduations.

Hereinafter, the present invention will be described based on an example implemented as an optical linear encoder.
1 and 2, the scale plate 3 which is a scale member of the optical linear encoder 1 as an absolute position detecting device has a light transmitting portion 5a and a light blocking portion whose longitudinal direction is, for example, 2 mm in the first stage. A first stage scale 5 in which a large number of first scales 5c made up of 5b are arranged in the longitudinal direction, and the longitudinal direction in the second stage is composed of a light transmitting portion 7a and a light blocking portion 7b having a width of, for example, 2.05 mm. Light transmission in which the longitudinal direction is, for example, 2.0525 mm wide in the second stage scale 7 and the third stage in which a plurality of second scales 7c are arranged in the longitudinal direction so that the first scales 5c of the scale 5 coincide with every 41. 3 which consists of a part 9a and a light blocking part 9b, and a plurality of third scales 9c are arranged in the longitudinal direction in such a manner that the second scale 7c of the second stage scale 7 is displaced every 40 pieces, and thus every 82 mm is 0.1 mm. The stage scale 9 is the first stage scale. The first-stage scale 5, the second-stage scale 7, and the third-stage scale 9 are provided in a parallel state in the longitudinal orthogonal direction at the left end in the figure, which is the home position of the lens 5.

In the above description, the light transmission portions 5a, 7a, and 9a of the first-stage scale 5, the second-stage scale 7, and the third-stage scale 9 are set to the left end of the home position that is the measurement origin of the scale plate 3. However, the home position may be the center of the scale plate 3 in the longitudinal direction, and the present invention is not limited by the home position on the scale plate 3. Further, the displacement width of the second scale 7c of the second-stage scale 7 relative to the first scale 5c of the first-stage scale 5 is set to 0.05 mm as described above, and 40 pieces of the second scale 7c are equivalent to 1 of the second-stage scale 7. However, the present invention is not limited to this numerical value, and can be arbitrarily set. Furthermore, although the displacement width of the third scale 9c of the third stage scale 9 relative to the second scale 7c of the second stage scale 7 is 0.0025 mm as described above, the present invention is not limited to this. What is necessary is just to set suitably according to the displacement width of the 2nd scale 7c with respect to the 1 scale 5c, and the 1 division | segmentation number of the 2nd scale 7c in the 2nd stage scale 7. FIG.

  The first light-emitting member 11a and the first light-receiving member 11b are arranged on the first-stage scale 5 and the first-stage scale 5 at a position sandwiching the scale plate 3 of the moving body 10 supported so as to be movable along the longitudinal direction of the scale plate 3. The second light emitting member 13a and the second light receiving member 13b are opposed to the second stage scale 7, and the third light emitting member 15a and the third light receiving member 15b are opposed to the third stage scale 9, and the first to third light emitting members. 11 a, 13 a, 15 a and the first to third light receiving members 11 b, 13 b, 15 b are attached in a row with respect to the longitudinal orthogonal direction of the scale plate 3.

Light emitting diodes or laser diodes are suitable as the first to third light emitting members 11a, 13a, and 15a, and photodiodes are suitable as the first to third light receiving members 11b, 13b, and 15b. 11b, the second light receiving member 13b, and the third light receiving member 15b are the first to third light emitting members 11a that are transmitted through the light transmitting portions 5a, 7a, and 9a of the scale plate 3, the first stage scale 5, and the second stage scale 7, respectively. Outputs electrical signals of pseudo sin waveform and pseudo cos waveform corresponding to the light intensity of light from 13a and 15a.

  In FIG. 3, the CPU 31 constituting the calculation means has a program memory 33 and a work memory 35, and the program memory 33 stores program data for detecting a moving position of the moving body 10 described later as an absolute position. . The work memory 35 includes a first count area 35a, a second count area 35b, a third count area 35c, and a work area 35d. The first count area 35a counts the number of divided input signals from the first light receiving member 11b described later. And it memorize | stores as position data between the 1st scales 5c. The second counting area 35b counts the number of displacements in which the input timing of the signal from the second light receiving member 13b deviates from the signal from the first light receiving member 11b, and stores data relating to the absolute value of the first scale 5c. The third counting area 35c counts the number of times that the input timing shift of the signal from the third light receiving member 15b with respect to the signal from the second light receiving member 13b reaches a predetermined section distance, and relates to the number of sections of the second-stage scale 7. Store as data. The work area 35d stores various data such as division number data necessary for executing an absolute position detection operation described later.

  On the other hand, the first light receiving member 11b, the second light receiving member 13b, and the third light receiving member 15b are connected to the CPU 31 via the A / D conversion means 37, and the first light receiving member 11b, The electric signals from the second light receiving member 13b and the third light receiving member 15b are converted into digital signals. Of the signals from the first light receiving member 11b, the second light receiving member 13b, and the third light receiving member 15b converted into digital signals, the signal from the first light receiving member 11b is divided by the dividing means 39 to detect the position of the moving body 10. Accordingly, the signal is divided into a predetermined number per cycle of the signal from the first light receiving member 11b. If the moving position detection resolution of the moving body 10 is 1 μm, the number of divisions is set to 2000 since the interval between the first graduations 5c is 2 mm. This division process is performed by the CPU 31. Then, the CPU 31 stores the number of divided input signals inputted and divided from the first light receiving member 11b in the first counting area 35a. Thereby, the distance between each first scale 5c in the first stage scale 5 is detected.

  The CPU 31 compares the A / D converted signal from the first light receiving member 11b with the signal from the second light receiving member 13b, and the input timing of the signal from the second light receiving member 13b with respect to the signal from the first light receiving member 11b is When there is a deviation, the number of displacements is counted by sequentially calculating. Now, since the arrangement interval of the first graduation 5c and the arrangement interval of the second graduation 7c are deviated by 0.05 mm as described above, the first graduation 5c and the second graduation until the first graduation 5c reaches 41 pieces. Deviation occurs between the scale 7c. Therefore, the number of the first graduations 5c is specified by counting the number of times the signal from the second light receiving member 13b is shifted with respect to the signal from the first light receiving member 11b. Then, the absolute position of the corresponding first scale 5c can be detected.

  Similarly, the CPU 31 compares the signal from the second light receiving member 13b after A / D conversion with the signal from the third light receiving member 15b, and compares the signal from the third light receiving member 15b with respect to the signal from the second light receiving member 13b. When the input timing is displaced by a predetermined distance, it is calculated and counted. Now, as described above, the interval between the third scales 9c is changed by 0.1 mm every time the measurement length of the second stage scale 7 becomes 82 mm (every 40 second scales 7c). The interval of the third scale 9c is set to 2.0525 mm with respect to the interval of the third scale 9c with respect to the interval of the second scale 7c. In the above example, the interval of the third scale 9c is set to 2.0525 mm. . Then, the second stage scale 7 is set to a plurality of sections for every 82 mm of the second scale 7c and 40 pieces, and the second scale 7 is moved by counting the number of times the deviation between the second scale 7c and the third scale 9c is 0.1 mm. It is specified in which section of the second-stage scale 7 the body 10 is located.

  The CPU 31 is provided with output control means 41. The output control means 41 is detected by an absolute position detection process, which will be described later, to a connected output member 43 such as a servo amplifier of a NC machine, a host computer, or an LCD or a printer. The moving position of the moving body 10 is output as an absolute position.

Next, the action of detecting the absolute position of the moving body 10 by the optical linear encoder 1 will be described.
When the moving body 10 is moved to the right from the moving origin (home position) at the left end of the scale plate 3 shown in the drawing, the light transmitting portion 5a and the light of the first-stage scale 5 in the scale plate 3 as the moving body 10 moves. With respect to the light transmitting part 7a and light blocking part 7b of the second stage scale 7 and the light transmitting part 9a and light blocking part 9b of the third stage scale 9, the first light emitting member 11a, the second light emitting member 13a, When the light from the third light emitting member 15a is increased or decreased, the corresponding first light receiving member 11b, second light receiving member 13b, and third light receiving member 15b output electric signals having a pseudo sine wave waveform and a cosine wave waveform.

  If, for example, the moving body 10 is located between the fifth and sixth first scales 5c of the first stage scale 5 of the scale plate 3 as shown in FIG. The converted signal from the third light receiving member 15b is compared with the signal from the second light receiving member 13b, and the input timing of the signal from the third light receiving member 15b is compared with the input timing of the signal from the second light receiving member 13b. It is determined whether the displacement width is relative to a predetermined amount. Now, as described above, since the moving body 10 is located at the position of the fifth first scale 5c in the first stage scale 5, the count value stored in the third count area 35c is '0', It is determined that the moving body 10 is located in the first section of the second stage scale 7.

  Similarly, the CPU 31 compares the signal from the second light receiving member 13b, which has been A / D converted, with the signal from the first light receiving member 11b, and outputs the signal from the second light receiving member 13b to the first light receiving member 11b. The number of displacements is stored by detecting the deviation and incrementing the second counting area 35b. Now, since the moving body 10 is located between the 5th of the 1st step scale 5 and the 6th 1st scale 5c in the scale board 3, CPU31 count value 'memorize | stored in the 2nd count area | region 35b. By 4 ′, it is determined that the moving body 10 has moved to a position beyond at least 8 mm from the left end of the scale plate 3 shown in FIG.

Further, the CPU 31 divides the A / D converted signal from the first light receiving member 11b by a predetermined number by the dividing means 39 and stores the number of divided input signals from the first light receiving member 11b in the first counting area 35a. Let Thus, the CPU 31 detects the distance from the first scale 5c located at the fifth position based on the count value stored in the first count area 35a in units of 1 μm according to the position detection resolution.

Then, the CPU 31 adds a unit (between the first scale 5c) to the value (0 mm) based on the section number data in the second-stage scale 7 stored in the third counting area 35c and the displacement number data stored in the second counting area 35b. A value obtained by multiplying the value (8 mm) multiplied by the distance and the distance between the first graduations 5c based on the divided input signal number data stored in the first counting area 35a is detected as the absolute position of the mobile body 10, This data is output to the output control means 41 and output to the output member 43 so that it can be confirmed by the NC machine or the operator.

On the other hand, for example, as shown in FIG. 5, if the moving body 10 is located between the 45th and 46th first scales 5 c in the first stage scale 5 of the scale plate 3, the CPU 31 first performs A / D. The converted signal from the third light receiving member 15b is compared with the signal from the second light receiving member 13b, and the input phase of the signal from the third light receiving member 15b is compared with the input phase of the signal from the second light receiving member 13b. It is determined whether or not the deviation is with respect to a predetermined amount. Now, it is determined that the moving body 10 is located between the 50th and 51st first scales 5 c and is located within the second section of the second stage scale 7. That is, the third scale 9c of the third stage scale 9 is displaced by a predetermined interval (0.1 mm in this example) every predetermined number (82 mm in this example) of the second scale 7c. Since they are arranged in a relationship, the division number of the second stage scale 7 is detected by counting the number of deviations at a predetermined interval. The CPU 31 determines that the moving body 10 is located in the second section of the second stage scale 7 based on the count value of the third counting area 35c, and the moving body 10 has exceeded at least 82 mm from the home position. Judged to be located at the location.

Similarly, the CPU 31 compares the signal from the second light receiving member 13b, which has been A / D converted, with the signal from the first light receiving member 11b, and outputs the signal from the second light receiving member 13b to the first light receiving member 11b. Detect the number of displacements. Now, since the moving body 10 is located between the 45th and 46th first scales 5c in the first stage scale 5, and the first scale 5c and the second scale 7c coincide with each other with 40 cycles, the above-mentioned is described. The displacement number becomes “4”. As a result, the CPU 31 determines that the moving bodies 10 are located at the fifth and sixth positions where one cycle is 40, based on the count value of the second count area 35b, and at least 8 mm or more.

Further, the CPU 31 divides the A / D converted signal from the first light receiving member 11b by a predetermined number by the dividing means 39 and stores the number of divided input signals from the first light receiving member 11b in the first counting area 35a. Based on the number of divided input signals, the position of the moving body 10 between the 45th and 46th positions on the first stage scale 5 is detected with a position detection resolution of 1 μm.

Then, the CPU 31 multiplies the section number data stored in the third count area 35c by the section distance data of the second stage scale 7 and the displacement number stored in the second count area 35b. A value obtained by adding the value (8 mm) obtained by multiplying the data by the unit distance of the first scale 5c and the distance between the first scale 5c based on the divided input number data stored in the first counting area 35a 10 is detected as an absolute position, and this data is output to the output control means 41 and output to the output member 43 so that it can be confirmed by the operator.

The present invention can be modified as follows.
1. In the above description, the scale plate 3 is provided with the third stage scale 9 to detect a distance that is a multiple of 82 mm as an absolute position. However, if the moving distance of the moving body 10 is 82 mm or less, As in the configuration described in Item 1, only the first-stage scale 5 and the second-stage scale 7 may be provided on the scale plate 3. On the other hand, by providing the scale member with four or more scale portions, even if the moving distance of the moving body 10 is long, the moving position can be detected as an absolute position.

2. Although the above description is configured as an optical linear encoder, the present invention can also be implemented as a rotary encoder. That is, as shown in FIG. 6, the scales 63a, 65a, 67a are respectively arranged in the circumferential direction on the outer peripheral side of the disk 61 or the outer peripheral surface of a cylindrical body (not shown) in the same relationship as in the first embodiment. The first stage scale 63, the second stage scale 65, and the third stage scale 67 arranged at the same pitch as the first stage scale 5, the second stage scale 7 and the third stage scale 9 in FIG. The first to third detection members (not shown) are provided with the first to third scales 63, 65, 67 of the disk 61 interposed therebetween. Since the absolute position detection operation is the same as that of the first embodiment, detailed description thereof is omitted.

3. Another example of the absolute position detecting rotary encoder will be described. As shown in FIG. 7, a light transmitting portion and a light blocking portion or different magnetic poles are provided on the outer peripheral side of the disk 71 or the outer peripheral surface of a cylindrical body (not shown). A large number of first scales 73 are formed so as to extend in the circumferential direction, for example, at an angle of 1 minute (1/60 degrees), and from the same light transmission part and light blocking part or different magnetic poles on the inner peripheral side thereof A plurality of second scales 75 are formed so as to extend in the circumferential direction, for example, at an angle of 1 degree, and third scales 77 of different magnetic poles are provided at the center of the disk 71 at intervals of 180 degrees.

  Then, the rotation angle (number of rotations) of the second scale 75 with one cycle of 360 degrees is detected by the third scale 77 and the number of deviations of the second scale 75 relative to the first scale 73 is detected. The rotation angle is specified, and the absolute position is detected by adding the angle calculated by dividing the first scale 73 according to the desired detection resolution. Specifically, the absolute position can be detected with a resolution of 0.2 seconds by dividing the first scale 73 by 300.

4). In the above description, the detection member is an optical detection member composed of a light emitting member and a light receiving member. However, the detection member may be composed of a magnetic element such as a Hall element, a magnetoresistive element, or a magnetic diode. Of course.

5. In the above description, the interval between the first graduations is 2 mm, the interval between the second graduations is 2.05 mm, and the interval between the third graduations is 2.0525 mm. It is technically very difficult to form a unit or nano unit.

  In order to solve this, as in the invention described in claims 3 and 4, for example, the scale interval of the first stage scale is, for example, 10 μm, the scale interval of the second stage scale is, for example, 2 mm, The scale interval is set to 2.05 mm, for example. The electrical signal output according to the scale of the second stage scale may be divided into, for example, 200 to specify the scale position on the first stage scale and detect the absolute position.

  In this case, the absolute position at a distance of 82 mm can be detected with a position detection resolution of 20 nm by dividing the electrical signal output corresponding to the scale of the first stage, for example, by 500. .

6). In claims 1 to 4, the arrangement pitch of the second scale in the second stage scale is defined as a relationship that matches every desired number with respect to the first scale of the first stage scale. The second scale 7c of the second stage scale 7 is made to coincide with the first scale 5c of the scale 5 for every predetermined number, and a distance of a desired distance (82 mm) or more is detected as an absolute position. In the case of detecting a distance equal to or less than (82 mm) as an absolute position, as long as the above-described predetermined relationship is maintained, the second scale is not necessarily matched with the first scale. Can be detected.

It is explanatory drawing which shows the outline of an absolute position detection apparatus. It is explanatory drawing of a scale board. It is an electrical block diagram of an absolute position detection apparatus. It is explanatory drawing which shows the example of an absolute position detection process. It is explanatory drawing which shows the example of an absolute position detection process. It is explanatory drawing which shows the outline in the case of using an absolute position detection apparatus as a rotary encoder. It is explanatory drawing which shows the other example of the rotary encoder for absolute position detection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Linear encoder 3 as absolute position detection device Scale plate 5 as scale member First stage scale 5a Light transmission part 5b Light blocking part 5c First scale 7 Second stage scale 7a Light transmission part 7b Light blocking part 7c Second scale 9 Third stage scale 9a Light transmission part 9b Light blocking part 9c Third scale 11a to 13a First to third light emitting members 11b to 13b First to third light receiving members 35a to 35c First to third counting areas

Claims (10)

A large number of at least second detectors having a pitch that matches every desired number with respect to the first scale of the first stage scale and the first scale of the first stage scale in which the first scales composed of at least the first detector units are arranged at a desired pitch. The second stage scale in which the second scales are arranged is provided in parallel with each other, and the electrical signal based on the scales of the first stage and the second stage scale provided so as to move relative to the scale member. At least the first and second detection members, the dividing means for dividing the first detection signal from the first detection member by the number corresponding to the desired position detection resolution, and the number of divided first detection signals A first counting means that counts the distance, a second counting means that detects the displacement of the second detection signal relative to the first detection signal and counts the number of displacements, and a distance between the first scales in the count value of the second counting means Multiplied by the first Absolute position detection device comprising a calculation means for detecting the absolute position by adding the count value by the number of means. A first stage scale in which a plurality of first graduations comprising at least first detectors are arranged at a desired pitch, and the first graduations are composed of at least second detectors having a pitch that matches every predetermined number of the first graduations. With respect to the second scale and the second scale in which a large number of second graduations are arranged, a large number of third graduations composed of at least a third detection unit are arranged in such a relationship that a predetermined displacement amount is obtained for each predetermined number of the second graduations. A scale member provided with the third-stage scales parallel to each other, and provided so as to move relative to the scale member, and at least outputs electrical signals based on the respective scales of the first-stage to third-stage scales. First to third detection members, dividing means for dividing the first detection signal from the first detection member by a number corresponding to a desired position detection resolution, and the number of first detection signals divided by output are counted. First Counting means; second counting means for counting the number of displacements based on the displacement of the second detection signal from the second detection member relative to the first detection signal; and a third detection signal from the third detection member for the second detection signal. A third counting unit that counts the number of times the displacement amount of the second stage becomes a predetermined amount, and a value obtained by multiplying the number of sections of the second-stage scale specified by the count value of the third counting means by the distance between the sections of the second-stage scale; An absolute position detecting device comprising a value obtained by multiplying the count value of the second counting means by the distance between the first graduations and the distance between the first graduations based on the count value obtained by the first counting means to detect the absolute position. . A first-stage scale in which at least a first scale composed of first detectors is arranged at a pitch corresponding to a desired position detection resolution, and a plurality of second scales composed of at least second detectors are a predetermined number times the pitch of the first scale. A scale member provided in parallel with each other and a scale member provided in parallel with each other and an electrical signal is output based on each scale of the first stage scale and the second stage scale. At least first and second detection members, dividing means for dividing the second detection signal from the second detection member by a number corresponding to a desired position detection resolution, and first counting means for counting the number of first detection signals And second counting means for detecting the displacement of the second detection signal divided with respect to the first detection signal and counting the number of displacements, and multiplying the count value of the second counting means by the distance between the first scales. By the first counting means Absolute position detection device comprising a calculation means for detecting the absolute position by adding a number. A first-stage scale in which a large number of first graduations comprising at least first detectors are arranged at a pitch according to a desired position detection resolution, and a plurality of second graduations comprising at least second detectors are a predetermined number of times the first graduation. In contrast to the second stage scale and the second scale arranged at a pitch of 3, the third stage scale in which a large number of third scales composed of at least third detection units are arranged in a predetermined amount for each predetermined number of second scales. Are provided so as to move relative to the scale member, and output at least first to third electric signals based on the scales of the first to third scales, respectively. A detection member; a dividing means for dividing the second detection signal from the second detection member by a number corresponding to a desired position detection resolution; a first counting means for counting the number of first detection signals; and a first detection signal. Vs. And a second counting means for detecting the displacement of the second detection signal divided and counting the number of displacements, and the number of times the displacement of the third detection signal from the third detection member relative to the second detection signal becomes a predetermined amount. Third counting means for counting, a value obtained by multiplying the number of sections of the second-stage scale specified by the count value of the third counting means by the distance between the sections of the second-stage scale, and the count value of the second counting means are the first An absolute position detection device comprising: a calculation unit for detecting an absolute position by adding a value obtained by multiplying a distance between the scales and a distance between the first scales based on a count value obtained by the first counting means. 5. The absolute position detection device according to claim 1, further comprising waveform shaping means for shaping an electric signal output from each detection member into a pseudo sine wave signal and a cosine wave signal. 5. The absolute position detection device according to claim 1, wherein each detection member is composed of an optical detection member composed of a light emitting member and a light receiving member, and each scale has a scale composed of a light transmitting portion and a light blocking portion. 5. The absolute position detecting device according to claim 1, wherein each detection member is composed of a magnetosensitive element, and each scale scale is composed of a magnetized portion. 5. The detection member according to claim 1, wherein a part of each detection member is an optical detection member made up of a light emitting member and a light receiving member, and the rest is made up of a magnetosensitive element, and a scale scale corresponding to the optical detection member is formed on the light transmission part and An absolute position detection device in which the scale of the scale corresponding to the light blocking unit and the magnetosensitive element is configured by the magnetized unit. 5. The absolute position detection device according to claim 1, wherein the scale member has a length corresponding to the detection distance, and each scale is provided in a multistage shape in parallel to the longitudinal direction. 5. The absolute position detecting device according to claim 1, wherein the scale member is provided with a plurality of scales extending in the circumferential direction with respect to the disk in a multistage shape in the radial direction.

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