MOTION DETECTOR DEVICE

Abstract

A motion detector device (31, 100, 100, 120, 300) for detecting the rotational movement or circulating movement of an object (32, 301), comprising the following components: a moving part (43, 111, 121, 312) which rotates or circulates in accordance with the rotational movement or the circulating movement of the object (32, 301); at least one pair of magnetic field generating parts (51, 52, 53, 54, 112, 122) which are located in the moving part (43, 111, 121, 312) and generate opposing magnetic fields; n magnetic field detection parts (61, 62, 63, 113, 123) (n is equal to 3 or more) located in a vicinity of the moving part (43, 111, 121, 312), each of which outputs a positive detection pulse as a result of a change in a magnetization direction when one of the one pair of magnetic field generating parts (51, 52, 53, 54, 112, 122) approaches, and each of which outputs a negative detection pulse as a result of a change in the magnetization direction when another of the one pair of magnetic field generating parts (51, 52, 53, 54, 112, 122) approaches; and a motion detector circuit (68) comprising a storage part (82), an operation processing part (81) and an update processing part, which receives detection pulses output from each of the magnetic field detector parts (61, 62, 63, 113, 123) and determines the state of the rotational movement or the circulating movement of the object (32, 301) on the basis of the received detection pulses, at least one pair of magnetic field generating parts (51, 52, 53, 54, 112, 122) and n magnetic field detecting parts (61, 62, 63, 113, 123) mounted in such a way that detection pulses having either a positive or a negative direction are continuously output by n magnetic field detecting parts (61, 62, 63, 113, 123) when the moving part (43, 111, 121, 312) rotates in one direction (the positive or negative directions of the corresponding n detection pulses generated during this time do not always have the same order), and positive or negative detection pulses are continuously output when the moving part (43, 111, 121, 312) rotates in the other direction (the positive or negative directions of the corresponding n Detection pulses generated during this time do not always have the same order), so that a constant pattern of a total of 2n detection pulses, which are emitted in different combinations and from different sources,arises, , the operation processing part (81) assigns the numbers 1, 2,..., n, n+1, n+2,..., 2n to 2n to the detection pulses forming the above-mentioned pattern, the storage part (82) stores the number of the last detection pulse output by one of the n magnetic field detection parts (61, 62, 63, 113, 123), the information about the direction of movement, information as to whether it is one direction or the other, whether the direction has not been identified, and whether there is an inversion to an unidentified state (hereinafter referred to as unrecognized inversion), the direction of movement of the moving part (43, 111, 121, 312) at the time when the last detection pulse was output, and the detection value of the movement speed indicating a speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when this last detection pulse was output, the operation processing part (81) decides, based on the difference between the number of the current detection pulse output by one of the n magnetic field detection parts (61, 62, 63, 113, 123) and the last detection pulse, the number of which has been stored in the memory part (82), as well as based on the information on the direction of movement and the detection value of the movement speed stored in the memory part (82), in which direction the movement part (43, 111, 121, 312) rotates, whether the direction has not been identified and whether an undetected inversion of the direction of movement of the movement part (43, 111, 121, 312) is taking place at the time when this current detection pulse is output, and decides or determines the speed of the rotational movement or the circulating movement of the movement part (43, 111, 121, 312) at the time, when this current detection pulse is output, the update processing part updates the number of the last detection pulse stored in the storage part (82) based on the number of the current detection pulse, updates the information on the direction of movement stored in the storage part (82) based on the decision of the operation processing part (81) and the direction of movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output, and updates the detection value of the movement speed stored in the storage part (82) based on the decision of the operation processing part (81) and the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output.

Description

[FIELD OF THE INVENTION]

[0001] The present invention relates to a motion detecting device for detecting the rotational motion or circulating motion of an object using magnetism. [INITIAL SITUATION OF THE INVENTION]

[0002] The Fig. Fig. 13 shows, as an example of a conventional rotation detecting device, a rotation detecting device whose construction is similar to the construction of the rotation detecting device shown in Fig. 1 of the following patent description 1. (Conventional rotation detector device)

[0003] The rotation detector device 300, which in Fig. 13 is a device that can determine, for example, the rotation direction and rotation speed of the rotating shaft 301 of a servo motor installed in the movable part of an industrial robot. The rotation detection device 300 includes the moving part 302, which is fixed to the rotating shaft 301 and rotates according to the rotation of the rotating shaft 301. The rotation direction and rotation speed of the moving part 302 correspond to the rotation direction and rotation speed of the rotating shaft 301.

[0004] The moving part 302 includes four magnets 311, 312, 313, and 314. The magnets 311, 312, 313, and 314 are arranged in the above-mentioned order at a distance of 90 degrees in the counterclockwise direction on the peripheral surface of the moving part 302. Furthermore, the magnets 311 and 313 are mounted with their N poles at the front, and the magnets 312 and 314 are mounted with their S poles at the front. This creates magnetic fields on the outer circumference of the moving part 302, whose direction of rotation reverses every 90 degrees.

[0005] In addition, three magnetic sensors 321, 322, and 323 are located near the moving part 302. Each of the magnetic sensors 321, 322, and 323 consists of a magnetic coil around which a magnetic double metal wire is wound, forming a magnetic element that generates a strong magnetic Barkhausen effect. The magnetic sensors 321, 322, and 323 are mounted in the above-described order in the clockwise direction, so that they are spaced 30 degrees apart from each other along the outer circumference of the moving part 302.

[0006] The magnets 311, 312, 313 and 314 are attached to the moving part 302 and change their position according to the rotation of the moving part 302, wherein the magnetic sensors 321, 322 and 323 are fixed to a support element not shown in the figure or to a similar construction and are immovable.

[0007] Once the magnet 311 reaches the magnetic sensor 321 due to the rotation of the moving part 302, the magnetization direction of the magnetic sensor 321 is inverted by the magnetic field generated by the magnet 311. Due to the electromotive force generated at this moment, a detection pulse (hereinafter referred to as a "positive-directed detection pulse") with a positive level is output by the magnetic sensor 321. The same occurs when the magnet 313 reaches the magnetic sensor 321. The same applies accordingly to the magnetic sensors 322 and 323.

[0008] When the magnet 312 reaches the magnetic sensor 321 during the rotation of the moving part 302, the magnetization direction of the magnetic sensor 321 is reversed by the magnetic field generated by the magnet 312. Due to the electromotive force generated at this moment, a detection pulse (hereinafter referred to as a "negative detection pulse") with a negative level is output by the magnetic sensor 321. The same occurs when the magnet 314 reaches the magnetic sensor 321. The same applies accordingly to the magnetic sensors 322 and 323.

[0009] However, there is a possibility that the magnetization direction of the magnetic sensor 321 is not inverted even after the magnet 311, 312, 313, or 314 reaches the magnetic sensor 321. In this case, neither a positive-going detection pulse nor a negative-going detection pulse is output by the magnetic sensor 321. For example, assume that the moving part 302 rotates in the right direction. Then, the magnet 311 reaches the magnetic sensor 321, the magnetization direction of the magnetic sensor 321 is inverted, a positive-going detection pulse is output by the magnetic sensor 321, and then the moving part 302 changes its rotation direction from left to right, and the magnet 311 reaches the magnetic sensor 321 again.In such a case, when the magnet 311 reaches the magnetic sensor 321 for the second time, neither a positive-going detection pulse nor a negative-going detection pulse is output by the magnetic sensor 321 because the reversal of the magnetization direction of the magnetic sensor 321 does not occur. The same applies accordingly to the magnetic sensors 322 and 323. The phenomenon in which the magnetization direction of the magnetic sensor is not inverted when a magnet reaches a magnetic sensor for the second or subsequent times, that is, when a magnet generates a magnetic field with the same rotation direction multiple times, will be referred to as "the magnetization direction has not been inverted as a result of generating a magnetic field with the same rotation direction" hereinafter.

[0010] Furthermore, the rotation detection device 300 includes the rotation detection circuit 330 for detecting the rotation direction and rotation speed of the moving part 302 based on the detection pulse output by each of the magnetic sensors 321, 322, and 323. The rotation detection circuit 330 receives the positive-direction detection pulses and the negative-direction detection pulses, respectively, sent by the magnetic sensors 321, 322, and 323. The rotation detection circuit 330 assigns numbers to the positive-direction detection pulses and the negative-direction detection pulses output by the magnetic sensors 321, 322, and 323.Namely, the number "1" is assigned to the positive-going detection pulse generated by the magnetic sensor 321, the number "2" is assigned to the positive-going detection pulse output by the magnetic sensor 322, and the number "3" is assigned to the positive-going detection pulse sent by the magnetic sensor 323. Next, the number "4" is assigned to the negative-going detection pulse generated by the magnetic sensor 321, the number "5" is assigned to the negative-going detection pulse output by the magnetic sensor 322, and the number "6" is assigned to the negative-going detection pulse sent by the magnetic sensor 323. The rotation detection circuit 330 performs the necessary operations using the numbers assigned to each detection pulse to determine the rotation direction and rotation speed of the moving part 302. (Four Types of Normal Processes)

[0011] Next, the four types of normal processes performed by the rotation detecting circuit 330 for determining the rotation direction and the rotation speed of the moving part 302 will be explained.

[0012] The first normal process is a process for determining the rotation speed of the moving part 302 because the moving part 302 rotates in the clockwise direction. The first normal process is performed as follows. For example, the moving part 302 rotates in the clockwise direction by approximately 180 degrees. Meanwhile, the magnet 311 sequentially reaches the magnetic sensors 321, 322, and 323, and the magnetization directions of the magnetic sensors 321, 322, and 323 are sequentially inverted. Then, the magnet 312 sequentially reaches the magnetic sensors 321, 322, and 323, and the magnetization directions of the magnetic sensors 321, 322, and 323 are sequentially inverted. In this case, the magnetic sensors 321, 322 and 323 generate the detection pulses in the following order: number “1”, number “2”, number “3”, number “4”, number “5”, number “6”.Accordingly, since the moving part 302 rotates in the right direction, the sequence of output detection pulses "1", "2", "3", "4", "5", and "6" is repeated. Based on this regularity, the rotation detection circuit 330 performs the following process as the first normal process. Namely, the rotation detection circuit 330 increases the rotation speed by 1 because the difference between the number of the last detection pulse generated by any one of the magnetic sensors 321, 322, and 323 and the number of the current detection pulse generated by any one of the magnetic sensors 321, 322, and 323 is 1, and the rotation direction when the last output detection pulse indicated the right direction.Specifically, since the number of the last output detection pulse is "6" and the number of the currently output detection pulse is "1", the rotation detector circuit 330 decides, according to the above-mentioned regularity, that the difference between the two numbers is 1. Specifically, the first normal process is described in sections 0127 to 0141 in FIG. Fig. 7 and in the upper part of the Fig. 8 of patent description 1 is explained in detail.

[0013] The second normal process is a process for determining the rotation speed of the moving part 302 because the moving part 302 rotates in the counterclockwise direction. The second normal process occurs as follows. For example, the moving part 302 rotates in the counterclockwise direction by approximately 180 degrees. Meanwhile, the magnet 314 sequentially reaches the magnetic sensors 323, 322, and 321, and the magnetization directions of the magnetic sensors 323, 322, and 321 are sequentially inverted. Then, the magnet 313 sequentially reaches the magnetic sensors 323, 322, and 321, and the magnetization directions of the magnetic sensors 323, 322, and 321 are sequentially inverted. In this case, the detection pulses sent by the magnetic sensors 321, 322 and 323 are output in the order of number “6”, number “5”, number “4”, number “3”, number “2”, number “1”.Accordingly, since the moving part 302 rotates in the left direction, the detection pulses are repeated in the order of "6", "5", "4", "3", "2", and "1". Based on this regularity, the rotation detection circuit 330 performs the following process as the second normal process. Namely, the rotation detection circuit 330 decreases the rotation speed by 1 because the difference between the number of the last detection pulse generated by any one of the magnetic sensors 321, 322, and 323 and the number of the current detection pulse outputted by any one of the magnetic sensors 321, 322, and 323 is 1, and the rotation direction when the last detection pulse was outputted was left.Specifically, since the number of the detection pulse output last is "1" and the number of the detection pulse output now is "6", the rotation detector circuit 330 decides that the difference between the two numbers is 1 according to the above-mentioned regularity.

[0014] The third normal process is a process for determining the rotation direction and rotation speed of the moving part 302 as the moving part 302 changes its rotation direction from left to right. The third normal process occurs as follows. For example, assume that the moving part 302 rotates approximately 90 degrees in the right direction; meanwhile, the magnet 311 sequentially reaches the magnetic sensors 321, 322, and 323, and the magnetization directions of the magnetic sensors 321, 322, and 323 are sequentially inverted.Suppose the moving part 302 then changes the rotation direction to the left and rotates approximately 180 degrees in the left direction; in the meantime, the magnet 311 sequentially reaches the magnetic sensors 323, 322, and 321, but the magnetization direction is not inverted in the magnetic sensors 321, 322, and 323 because a magnetic field with the same rotation direction exists; then the magnet 314 sequentially reaches the magnetic sensors 323, 322, and 321, and the magnetization directions of the magnetic sensors 323, 322, and 321 are sequentially inverted. In this case, the detection pulses are generated by the magnetic sensors 321, 322, and 323 in the order of number "1", number "2", number "3", number "6", number "5", and number "4".It should be noted here that the number of the detection pulse last output before the rotation direction of the moving part 302 was changed is "3", the number of the detection pulse first output after the rotation direction of the moving part 302 was changed is "6", and the difference between these numbers is 3. Accordingly, when the moving part 302 changes the rotation direction, the difference between the numbers of the detection pulses before and after the rotation direction change is 3. Based on this regularity, the rotation detecting circuit 330 performs the following process as the third normal process.Namely, the rotation detection circuit 330 judges that the rotation direction of the moving part 302 has changed from left to right and decreases the rotation speed by 3 because the difference between the number of the last detection pulse generated by any one of the magnetic sensors 321, 322, and 323 and the number of the detection pulse now output by any one of the magnetic sensors 321, 322, and 323 is 3, and the rotation direction when the last detection pulse was output was right. Specifically, the third normal process is described in sections 0157 to 0168 in FIG. Fig. 7 and in the upper part of the Fig. 9 of patent description 1 is explained in detail.

[0015] The fourth normal process is a process for determining the rotation direction and rotation speed of the moving part 302 as the moving part 302 changes the rotation direction from left to right. The fourth normal process is a process that is executed, for example, in the case where the moving part 302 rotates in the left direction by approximately 90 degrees, then changes the rotation direction to the right, and rotates in the right direction by approximately 180 degrees. Therefore, compared to the above-described third normal process that is executed when the moving part 302 reverses the rotation direction from right to left, the fourth normal process is a process that takes place when the moving part 302 changes the rotation direction from left to right.In the fourth normal process, the rotation detecting circuit 330 decides that the rotation direction of the moving part 302 has been changed from left to right and increases the rotation speed by 3 because the difference between the number of the last detection pulse outputted by any one of the magnetic sensors 321, 322, and 323 and the number of the current detection pulse outputted by any one of the magnetic sensors 321, 322, and 323 is 3, and the rotation direction at the time when the last detection pulse was outputted was left.

[0016] When the moving part 302 begins to rotate only when the rotation detecting device 300 starts its operation, the rotation direction of the moving part 302 is determined depending on whether the value obtained by subtracting the number of the detection pulse generated by the magnetic sensor 321 from the number of the detection pulse output by the magnetic sensor 322 is positive or negative, and the result is stored as the rotation direction information in the storage element included in the rotation detecting circuit 330. Subsequently, the rotation direction information stored in the storage element is updated each time the change in the rotation direction of the moving part 302 is detected through the above-mentioned processes.The rotation detection circuit 330 can know the direction of rotation that existed at the time when the last detection pulse was output by reading the rotation direction information in the memory element. (Missing detection pulse)

[0017] The four normal processes described above that occur in the rotation detection circuit 330 are processes based on the assumption that when the magnetization direction of any one of the magnetic sensors 321, 322, or 323 is inverted, a detection pulse is output from the corresponding magnetic sensor each time. However, in each of the magnetic sensors 321, 322, and 323, a situation may arise in which the detection pulse is not output regardless of the reversal of the magnetization direction, that is, a detection pulse is missing. Since a detection pulse is missing, it is impossible to correctly determine the rotation direction and rotation speed of the moving part 302 within the scope of the above-mentioned normal processes.

[0018] The situation in which the correct determination of the rotation direction and the rotation speed of the moving part 302 by means of the above-mentioned normal processes is impossible because of the lack of a detection pulse will be explained using two examples that may occur during the operation of the rotation detecting device 300.

[0019] The first operation example is as follows. For example, assume that the moving part 302 rotates approximately 150 degrees in the right direction. Meanwhile, the magnet 311 sequentially reaches the magnetic sensors 321, 322, and 323, and the magnetization directions of the magnetic sensors 321, 322, and 323 are sequentially inverted. Then, the magnet 312 sequentially reaches the magnetic sensors 321 and 322, and the magnetization directions of the magnetic sensors 321 and 322 are sequentially inverted. In this case, the detection pulses generated by the magnetic sensors 321, 322, and 323 are output in the order of "1," "2," "3," "4," and "5." Assume that during this operation, a negative-directed detection pulse (number "4"), which should be generated by the magnetic sensor 321, is missing. In this case, the detection pulses are sent in the order number "1", number "2", number "3", number "5".

[0020] The second operation example is as follows. For example, assume that the moving part 302 rotates approximately 90 degrees in the right direction. Meanwhile, the magnet 311 sequentially reaches the magnetic sensors 321, 322, and 323, and the magnetization directions of the magnetic sensors 321, 322, and 323 are sequentially inverted. Subsequently, assume that the moving part 302 changes its rotation direction to the left and rotates approximately 150 degrees in the left direction. The magnet 311 then sequentially reaches the magnetic sensors 323, 322, and 321, but the magnetization directions of the magnetic sensors 321, 322, and 323 are not inverted due to the presence of a magnetic field with the same rotation direction. Then, the magnet 314 successively reaches the magnetic sensors 323 and 322, and the magnetization directions of the magnetic sensors 323 and 322 are successively inverted.In this case, the detection pulses generated by the magnetic sensors 321, 322, and 323 are output in the order of number "1," number "2," number "3," number "6," and number "5." Suppose that, during this operation, a negative-going detection pulse (number "6") that should be generated by the magnetic sensor 323 is missing. In this case, the detection pulses are output in the order of "1," "2," "3," and "5."

[0021] Comparing the case where the negative detection pulse from the magnetic sensor 321 is missing in the first operation example with the case where the negative detection pulse that should be output from the magnetic sensor 323 is missing in the second operation example, it becomes apparent that the detection pulses are output in the same order in both cases. In this case, it is impossible to identify these two operations within the scope of the above-mentioned normal processes, and consequently, it is not possible to correctly determine the rotation direction and rotation speed of the moving part 302. (Missing complementary process)

[0022] The rotation detector circuit 330 includes a function for performing processes that replace such missing detection pulses (hereinafter referred to as "missing complementary processes") and are intended to enable the determination of the correct rotation direction and rotation speed of the moving part 302. Three examples of a missing complementary process are explained below.

[0023] The first example of a missing complementary process occurs when the moving part 302 does not change the rotation direction. The first example of a missing complementary process is as follows. For example, assume that the moving part 302 rotates approximately 180 degrees in the clockwise direction. Meanwhile, the magnet 311 sequentially reaches the magnetic sensors 321, 322, and 323, and the magnetization directions of the magnetic sensors 321, 322, and 323 are sequentially inverted; then, the magnet 312 sequentially reaches the magnetic sensors 321, 322, and 323, and the magnetization directions of the magnetic sensors 321, 322, and 323 are sequentially inverted. In this case, the detection pulses generated by the magnetic sensors 321, 322 and 323 are output in the order of number “1”, number “2”, number “3”, number “4”, number “5” and number “6”.In this operation, when a negative-directed detection pulse (number “4”) that should be generated by the magnetic sensor 321 is missing, the detection pulses are output in the order “1”, “2”, “3”, “5”, “6”.

[0024] In this case, the rotation detection circuit 330 executes the above-mentioned first normal process from the time when the detection pulse numbered "1" is output until the time when the detection pulse numbered "3" is generated, so as to increase the rotation speed of the moving part 302 by 1 each time a detection pulse is output. Then, when the detection pulse numbered "5" is output, the rotation detection circuit 330 detects that a detection pulse that should be output at that time is missing because a detection pulse numbered "3" is followed by a detection pulse numbered "5," and the difference between the number "5" of the current detection pulse and the number "3" of the detection pulse output immediately before the current detection pulse is 2 and is neither 1 nor 3.Subsequently, when the detection pulse numbered "5" is output, the rotation speed of the moving part 302 is not changed by the rotation detection circuit 330. At the time when the detection pulse numbered "6" is output, the rotation detection circuit 330 subtracts the number "5" of the detection pulse output immediately before the current detection pulse from the number "6" of the current detection pulse, obtaining the value 1, and therefore judges that the rotation direction of the moving part 302 was right at the time the detection pulse numbered "6" was output.Then, when the detection pulse with the number "6" is output, the rotation detection circuit 330 subtracts the number "3" of the detection pulse (the second to last detection pulse) output twice before the current detection pulse from the number "6" of the current detection pulse, and changes the rotation speed of the moving part 302 based on the value obtained by this subtraction, and changes the rotation direction of the moving part 302 when the detection pulse with the number "6" is output.

[0025] Namely, if the rotation direction of the moving part 302 is right at the time when the determination of the rotation direction and the rotation speed is carried out (in this example, at the time when the detection pulse with the number “6” is output), and if the value obtained by subtracting the number of the detection pulse that was output twice before the current detection pulse from the number of the current detection pulse that is output at the time when the determination of the rotation direction and the rotation speed is carried out is g (a positive value), the rotation speed of the moving part 302 is increased by g.Furthermore, if the rotation direction of the moving part 302 was right at the time when the determination of the rotation direction and the rotation speed was performed, and if the value obtained by subtracting the number of the detection pulse output twice before the current detection pulse from the number of the current detection pulse output at the time when the determination of the rotation direction and the rotation speed takes place is -h (a negative value), the rotation speed of the moving part 302 is increased by (6-h) (6 in this case means the number of types of detection pulses). In this example, since the rotation direction of the moving part 302 is right at the time when the determination of the rotation direction and the rotation speed is performed, that is,, at the time when the detection pulse with the number "6" is output, and since the value obtained by subtracting the number of the detection pulse output twice before the current detection pulse from the number of the current detection pulse output at the time when the detection pulse with the number "6" is generated is 3, the rotation detector circuit 330 increases the rotation speed of the moving part 302 by 3. As mentioned above, when there is no negative detection pulse that should be output by the magnetic sensor 321, the detection pulses are output in the order of number "1", number "2", number "3", number "4", number "5", number "6", and the rotation speed of the moving part 302, which rotates in the clockwise direction until the detection pulse with the number "6" is output after the detection pulse with the number "3" is generated, is increased by 3.At this moment, it becomes obvious that the decision to increase the rotation speed of the moving part 302 by 3, which was made by the missing complementary process, is correct. In particular, the first example of a missing complementary process is shown in sections 0142 to 0156 in . Fig. 7 and in the lower part of the Fig. 8 of patent description 1 is explained in detail.

[0026] The second example of a missing complementary process describes a missing complementary process because the moving part 302 changes the rotation direction once. The second example of a missing complementary process is as follows. For example, assume that the moving part 302 rotates approximately 90 degrees in the right direction. Meanwhile, the magnet 311 successively reaches the magnetic sensors 321, 322, and 323, and the magnetization directions of the magnetic sensors 321, 322, and 323 are successively inverted. Thus, it is assumed that the moving part 302 changes the rotation direction from right to left and rotates approximately 180 degrees in the left direction. Meanwhile, the magnet 311 successively reaches the magnetic sensors 323, 322 and 321, but the magnetization directions of the magnetic sensors 321, 322 and 323 are not inverted by the presence of a magnetic field with the same rotation direction.Subsequently, the magnet 314 sequentially reaches the magnetic sensors 323, 322, and 321, and the magnetization directions of the magnetic sensors 323, 322, and 321 are sequentially inverted. In this case, the detection pulses generated by the magnetic sensors 321, 322, and 323 are output in the order of number "1," number "2," number "3," number "6," number "5," and number "4." During this operation, if a negative-directed detection pulse (number "6") that should be generated by the magnetic sensor 323 is missing, the detection pulses are output in the order of "1," "2," "3," "5," and "4."

[0027] In this case, the rotation detection circuit 330 executes the above-mentioned first normal process from the time when the detection pulse numbered "1" is output until the time when the detection pulse numbered "3" is sent, and increases the rotation speed of the moving part 302 by 1 each time a detection pulse is output. Thus, at the time when the detection pulse numbered "5" is output, the rotation detection circuit 330 detects that a detection pulse is missing in the period between the detection pulse numbered "5" and the detection pulse numbered "3" because the difference between the number "5" of the current detection pulse and the number "3" of the detection pulse output immediately before the current detection pulse is 2 and is neither 1 nor 3.Therefore, when the detection pulse numbered "5" is output, the rotation speed of the moving part 302 is not changed by the rotation detection circuit 330. At the time when the detection pulse numbered "4" is output, the rotation detection circuit 330 subtracts the number "5" of the detection pulse output immediately before the current detection pulse from the number "4" of the current detection pulse, which is -1, and therefore determines that the rotation direction of the moving part 302 is left at the time when the detection pulse numbered "4" is output.Later, at the time when the detection pulse numbered “4” is output, the rotation detection circuit 330 subtracts the number “3” of the detection pulse (the second to last detection pulse) outputted twice before the current detection pulse from the number “4” of the current detection pulse, and changes the rotation speed of the moving part 302 based on the subtracted value, and changes the rotation direction of the moving part 302 at the time when the detection pulse numbered “4” is output.

[0028] If the moving part 302 rotates to the left at the time when the determination of the rotation direction and the rotation speed is carried out (in this example, at the time when the detection pulse with the number “4” is output), and if the value obtained by subtracting the number of the detection pulse that was output twice before the current detection pulse from the number of the current detection pulse that is output at the time when the determination of the rotation direction and the rotation speed is carried out is -i (a negative value), the rotation speed of the moving part 302 is reduced by i.In addition, the moving part 302 rotates to the left at the time when the determination of the rotation direction and the rotation speed is carried out, and if the value obtained by subtracting the number of the detection pulse that was output twice before the current detection pulse from the current detection pulse sent at the time when the determination of the rotation direction and the rotation speed is carried out is j (a positive value), the rotation speed of the moving part 302 is reduced by (6-j) (6 in this case means the number of types of detection pulses). In this example, since the rotation direction of the moving part 302 at the time when the determination of the rotation direction and the rotation speed is carried out, that is,, at the time when the detection pulse with the number "4" is output, is to the left and the value obtained by subtracting the number of the detection pulse that was output twice before the current detection pulse from the current detection pulse output at the time when the detection pulse with the number "4" is output is 1, the rotation detection circuit 330 decreases the rotation speed of the moving part 302 by 5. As mentioned above, when no negative-going detection pulse is missing in the magnetic sensor 323, the detection pulses are output in the order of number "1", number "2", number "3", number "6", number "5", number "4", and the rotation speed of the moving part 302, which rotates to the left in the period between the detection pulse with the number "4" and the detection pulse with the number "3", is reduced by 5.Thus, it becomes clear that the decision to reduce the rotational speed of the moving part 302 by 5, which was made in the absence of the complementary process, is correct. Specifically, the second example of a lack of the complementary process is described in sections 0169 to 0184 in . Fig. 7 and in the lower part of the Fig. 9 of patent description 1 is explained in detail.

[0029] The third example of a missing complementary process occurs when the moving part 302 changes its rotation direction twice. The third example of a missing complementary process is as follows. For example, assume that the moving part 302 rotates approximately 90 degrees in the right direction. Meanwhile, the magnet 311 sequentially reaches the magnetic sensors 321, 322, and 323, and the magnetization directions of the magnetic sensors 321, 322, and 323 are sequentially inverted.Then, suppose that the moving part 302 changes the rotation direction to the left and rotates in the left direction by about 120 degrees, in the meantime, the magnet 311 sequentially reaches the magnetic sensors 323, 322 and 321, but the magnetization directions of the magnetic sensors 321, 322 and 323 are not inverted by the presence of a magnetic field having the same rotation direction Then, the magnet 314 reaches the magnetic sensor 323 and the magnetization direction of the magnetic sensor 323 is inverted.Furthermore, suppose that the moving part 302 changes the rotation direction to the right and rotates in the right direction by approximately 150 degrees. In the meantime, the magnet 314 reaches the magnetic sensor 323, but the magnetization direction of the magnetic sensor 323 is not inverted by the presence of a magnetic field with the same rotation direction. Then, the magnet 311 successively reaches the magnetic sensors 321 and 322, but the magnetization directions of the magnetic sensors 321 and 322 are not inverted by the presence of a magnetic field with the same rotation direction. Then, the magnet 311 reaches the magnetic sensor 323, and the magnetization direction of the magnetic sensor 323 is inverted. Furthermore, the magnet 312 reaches the magnetic sensor 321, and the magnetization direction of the magnetic sensor 321 is inverted.In this case, the detection pulses generated by the magnetic sensors 321, 322, and 323 are output in the order of number "1," number "2," number "3," number "6," number "3," and number "4." During this operation, if a positive-going detection pulse (number "3") that should be generated by the magnetic sensor 323 is missing, the detection pulses are output in the order of "1," "2," "6," "3," and "4."

[0030] In this case, the rotation detection circuit 330 performs the above-mentioned first normal process from the time when the detection pulse number "1" is output until the time when the detection pulse number "2" is generated, so as to increase the rotation speed of the moving part 302 by 1 each time the detection pulse is output. Thus, at the time when the detection pulse number "6" is output, the rotation detection circuit 330 detects that a detection pulse is missing in the period between the detection pulse number "6" and the detection pulse number "2" because the difference between the number "6" of the current detection pulse and the number "2" of the detection pulse output immediately before the current detection pulse is 4 and neither 1 nor 3.Later, at the time when the detection pulse number “6” is output, the rotation speed of the moving part 302 is not changed by the rotation detecting circuit 330.Further, at the time when the detection pulse with the number "3" is output, the rotation detection circuit 330 subtracts the number "6" of the detection pulse output immediately before the current detection pulse from the number "3" of the current detection pulse and obtains a value that is neither 1 nor -1, then the rotation detection circuit 330 subtracts the number "2" of the detection pulse output twice before the current detection pulse from the number "3" of the current detection pulse and obtains a value that is 1, and therefore decides that the rotation direction of the moving part 302 was right at the time when the detection pulse with the number "3" was output (this decision stage is described at items S7 and S9 of the . Fig. 7 in Patent Specification 1). Later, when the detection pulse numbered "3" is output, the rotation detection circuit 330 subtracts the number "2" of the detection pulse output twice before the current detection pulse from the number "3" of the current detection pulse, and changes the rotation speed of the moving part 302 based on the subtracted value, as well as changes the rotation direction of the moving part 302 at the time when the detection pulse numbered "3" is output.Namely, since the rotation direction of the moving part 302 is right at the time when the detection pulse numbered “3” is output, and the value obtained by subtracting the number of the detection pulse outputted twice before the current detection pulse from the number of the current detection pulse outputted at the time when the detection pulse numbered “3” is output is 1, the rotation detecting circuit 330 increases the rotation speed of the moving part 302 by 1.As mentioned above, when a positive-going detection pulse that should be generated by the magnetic sensor 323 is missing, the detection pulses are output in the order of number "1", number "2", number "3", number "6", number "3", number "4", and the rotation speed of the moving part 302, which rotates first in the left direction and then in the right direction in the period until the detection pulse with number "3" is output for the second time after the detection pulse with number "2" is output, is increased by 1. At this time, it is obvious that the decision made by the missing complementary process about decreasing the rotation speed of the moving part 302 by 1 is correct. In particular, the third example of a missing complementary process is described in sections 0197 to 0212 in . Fig. 7 and in the lower part of the Fig. 10 of patent description 1 is explained in detail.

[0031] By eliminating such complementary processes, the accuracy of determining the rotation direction and rotation speed of the rotating shaft 301 (the moving part 302) can be improved. Further details about the rotation detection device 300 are described in the related art. [State of the art]

[0032] Document JP 2014 - 112 113 A discloses a motion detection device for detecting a rotational movement or circumferential movement of a detection object, wherein the movable part rotates or orbits according to the rotational movement or circumferential movement of the detection object, and a magnetic field having a first direction, at least two first magnetic field generators generating a first magnetic field, and at least two second magnetic fields generating a second magnetic field having a second direction opposite to the first direction; When the first magnetic field generator of one of the at least two first magnetic field generators approaches each other, the first magnetic field is magnetized by the first magnetic field in the first direction; when a second magnetic field generating unit of at least two second magnetic field generating units approaches,the second magnetic field is magnetized in the second direction by the second magnetic field, and the magnetization direction is the first direction. Alternating between the direction and the second direction. At least three magnetic field detectors that output detection pulses generated by the electromotive force generated in the first and second detection pulses output by the magnetic field detectors, and the rotational movement of the detection object based on the received detection pulses. Alternatively, the at least two first magnetic field generating units and the at least two second magnetic field generating units may include a movement detection circuit for detecting a circumferential movement state in an outer peripheral portion of the movable portion in a circumferential direction. The first magnetic field generator and the second magnetic field generator are arranged alternately,and the at least three magnetic field detectors rotate the movable part near the outer peripheral part of the movable part. The at least two first magnetic field generating parts and the at least two second magnetic field generating parts are arranged along a locus of the outer peripheral part of the movable part when the movable part moves or rotates. The point at which the magnetization direction of each of the magnetic field detecting units is changed between the first direction and the second direction while the movable unit rotates to the right is defined as a right-turn reaction point. In the two first magnetic field generating units and the at least two second magnetic field generating units, the magnetization directions of the respective magnetic field detecting units are set to the first direction and the second direction while the movable unit rotates to the left. Assuming that the points,between which the directions are to be changed are reaction points for left rotation, the position of each of the magnetic field detection units is determined by one of the at least three magnetic field detection units of the plurality of reaction points for right rotation. Each of the other magnetic field detection units of the at least three magnetic field detection units does not face any of the plurality of reaction points for right rotation when it faces one of the reaction points for right rotation of the at least three magnetic field detection units. One of the compartments. If a magnetic field detection unit faces a reaction point for left rotation of the plurality of reaction points for left rotation,Each of the other magnetic field detection units of the at least three magnetic field detection units is one of the plurality of reaction points for the left rotation. If none of the magnetic field detection units of the at least three magnetic field detection units are missing detection pulses, the motion detection circuit is configured to detect the first detection pulse output by one of the at least three magnetic field detectors immediately before the missing detection pulse, and the magnetic field detector of one of the at least three magnetic field detectors immediately after the missing detection pulse. Immediately after the second detection pulse output by the magnetic field detection unit of one of the at least three magnetic field detection units. And third detection pulse and motion detection device, characterized by determining the range of movement of the movable part with.,

[0033] Document JP 2013 - 044 606 A discloses a motion detection device for detecting a rotational movement or circumferential movement of a detection object, wherein the movable part rotates or orbits according to the rotational movement or circumferential movement of the detection object, and a magnetic field having a first direction, at least two first magnetic field generators generating a first magnetic field, and at least two second magnetic fields generating a second magnetic field having a second direction opposite to the first direction; When the first magnetic field generator of one of the at least two first magnetic field generators approaches each other, the first magnetic field is magnetized by the first magnetic field in the first direction; when a second magnetic field generating unit of at least two second magnetic field generating units approaches,the second magnetic field is magnetized by the second magnetic field in the second direction, and the magnetization direction is the first direction. Alternating between the direction and the second direction. At least three magnetic field detectors that output detection pulses generated by the electromotive force generated in the first and second detection pulses output by the magnetic field detectors, and the rotational movement of the detection object based on the received detection pulses. Alternatively, the at least two first magnetic field generating units and the at least two second magnetic field generating units may include a movement detection circuit for detecting a circumferential movement state in an outer peripheral portion of the movable portion in a circumferential direction. The first magnetic field generator and the second magnetic field generator are arranged alternately,and the at least three magnetic field detectors rotate the movable part near the outer peripheral part of the movable part. The at least two first magnetic field generating parts and the at least two second magnetic field generating parts are arranged along a locus of the outer peripheral part of the movable part when the movable part moves or rotates. The point at which the magnetization direction of each of the magnetic field detecting units is changed between the first direction and the second direction while the movable unit rotates to the right is defined as a right-turn reaction point. In the two first magnetic field generating units and the at least two second magnetic field generating units, the magnetization directions of the respective magnetic field detecting units are set to the first direction and the second direction while the movable unit rotates to the left. Assuming that the points,between which the directions are to be changed are reaction points for left rotation, the position of each of the magnetic field detection units is determined by one of the at least three magnetic field detection units of the plurality of reaction points for right rotation. Each of the other magnetic field detection units of the at least three magnetic field detection units does not face any of the plurality of reaction points for right rotation when it faces one of the reaction points for right rotation of the at least three magnetic field detection units. One of the compartments. When a magnetic field detection unit faces a reaction point for left rotation of the plurality of reaction points for left rotation, each of the other magnetic field detection units of the at least three magnetic field detection units is one of the plurality of reaction points for left rotation. A movement detection device, characterized in that none of them are opposite each other. [PATENT CLAIMS][PROBLEMS TO BE SOLVED BY THE INVENTION]

[0034] The rotation detection circuit 330 of the above-mentioned rotation detection device 300 (the rotation detection device is described in the related art) is equipped with a memory element. A portion of the memory area of this memory element is used to store information used in performing processes for determining the rotation direction and rotation speed of the moving part 302.

[0035] It is necessary to expand the memory area used for other processes in this memory element. To meet this requirement, the volume of information used in performing processes for determining the rotation direction and rotation speed of the moving part 302, as well as the memory area of the memory element used for these processes, would have to be reduced.

[0036] All of the above-mentioned first to fourth normal processes are processes for determining the rotation direction and rotation speed of the moving part 302. The first to fourth normal processes are performed using the following three pieces of information: the number of the last detection pulse output, the rotation direction of the moving part 302 at the time the last detection pulse is output, and the rotation speed of the moving part 302 at the time the last detection pulse is output. Therefore, these three pieces of information are stored in the memory element by the rotation detection circuit 330. In addition, the missing complementary processes are performed using the following additional information: the number of the detection pulse that was previously output twice, and the information as to whether a detection pulse was missing.Therefore, these two pieces of information are also stored in the memory element by the rotation detector circuit 330.

[0037] After analyzing which of the five pieces of information used in the processes for determining the rotation direction and rotation speed of the moving part 302 could be omitted to reduce the storage area in the memory element, it was determined that the three pieces of information used in the first to fourth normal processes can hardly be removed because this information forms the basis for determining the rotation of the moving part 302. Therefore, it can only be a matter of removing the other two pieces of information used exclusively for missing complementary processes: the number of the detection pulse that was previously output twice and the information about whether a detection pulse was missing. If the method of the above-mentioned missing complementary processes is not changed, it is impossible to omit these two pieces of information.Furthermore, it is not easy to develop another method for missing complementary processes.

[0038] The present invention was developed with the above-mentioned problems in mind. Therefore, the primary object of the present invention is to develop a motion detection device that does not require information to be used in the absence of a detection pulse from a magnetic field detection section.

[0039] The second object of the present invention is to develop a motion detecting device capable of replacing a missing detection pulse from a magnetic field detecting part without knowing the number of the detection pulse previously outputted twice. [METHODS TO SOLVING THE PROBLEMS]

[0040] The present invention is defined in the independent claims. The dependent claims define preferred embodiments of the invention. [BENEFITS OF THE INVENTION]

[0041] By means of the present invention, it is possible to complement a missing detection pulse of the magnetic field detector part without using the detection pulse that was previously output twice and thus to reduce the information volume required in the processes for replacing a missing detection pulse of the magnetic field detector part. [BRIEF DESCRIPTION OF THE DRAWINGS] [ Fig. 1] is a schematic representation of the rotation detector device according to the invention. [ Fig. 2] is a schematic representation of the rotation detector device according to the invention, seen from the side indicated by the arrows II-II in Fig. 1 direction shown. [ Fig. 3] is a schematic diagram of the rotation detecting circuit of the rotation detecting device according to the invention. [ Fig. 4] is a flowchart illustrating the rotation detection process performed in the rotation detecting device according to the present invention. [ Fig. 5] is a continuation of the flow chart in Fig. 4. [ Fig. 6] is a continuation of the flow chart in Fig. 4. [ Fig. 7] is a schematic diagram showing the relationship between the movements of the moving part and the information used to perform the rotation detection process in the rotation detecting device according to the present invention. [ Fig. 8] is a schematic diagram showing the relationship between the movements of the moving part and the information used to perform the rotation detection process in the rotation detection device according to the present invention. [ Fig. 9] is a schematic representation of the relationship between the movements of the moving part and the information used to perform the rotation detection process in the rotation detecting device according to the invention. [ Fig. 10] is a schematic representation of an embodiment of the rotation detecting device according to the invention. [ Fig. 11] is a schematic diagram of another embodiment of the rotation detecting device according to the present invention. [ Fig. 12] is a schematic representation of the movement detector device according to the invention for detecting circulation movements. [ Fig. 13] is a schematic diagram of another rotation detecting device. [EMBODIMENTS OF THE INVENTION]

[0042] In the remainder of the present text, the embodiments of the present invention will be described with reference to the drawings. (Structure of the rotation detector device)

[0043] Fig. 1 shows the rotation detector device in its inventive form, Fig. Figure 2 shows a section of the rotation detector device, seen from the direction indicated by arrows II-II in Fig. 1 direction shown.

[0044] In Fig. 1, the rotation detector device 31 is shown as an embodiment of the motion detector device according to the invention in the form of a device for detecting the rotational movement, or more precisely, the direction and speed of rotation, of a specific object. The rotation detector device 31 can be used to determine the rotational movement of various objects. In the present embodiment of the invention, the object is, for example, the rotating shaft 32 of a servomotor installed in the moving part of an industrial robot.

[0045] The rotation detector device 31 is equipped with a housing 41, which is made, for example, of a plastic or other comparable material and has the shape of a cylinder with a lid. The housing 41 has mounting holes 42 that movably accommodate the rotating shaft 32. The housing 41 is attached, for example, to an industrial robot using a connecting element (not shown).

[0046] The moving part 43 is located within the housing 41. The moving part 43 is designed, for example, in a columnar shape and is connected to the rotating shaft 32 such that its center coincides with the axis of the rotating shaft 32. Since the moving part 43 rotates together with the rotating shaft 32, the rotation direction and rotation speed of the moving part 43 coincide with the rotation direction and rotation speed of the rotating shaft 32.

[0047] On the outer circumference of the moving part 43, there are four (two pairs of) magnets 51, 52, 53, and 54. The magnets 51, 52, 53, and 54 are mounted in this order in the left direction on the circumference of the moving part 43 at intervals of 90 degrees around the rotating shaft 32. Each of the magnets 51 and 53 is inside the moving part 43, as shown in Fig. 1, with its N pole at the front and its S pole at the rear. Furthermore, each of the magnets 52 and 54 is arranged within the moving part 43, as shown in Fig. 1, with its S pole at the front and its N pole at the rear. Thus, 43 magnetic fields are generated on the outer circumference of the moving part, whose directions reverse every 90 degrees. Magnets 51, 52, 53, and 54 serve as specific examples of the magnetic field generating parts.

[0048] Furthermore, three magnetic sensors 61, 62, and 63 are disposed within the housing 41 in the periphery of the moving part 43 and near the outer circumference of the moving part 43. Each of the magnetic sensors 61, 62, and 63 includes a magnetic double metal wire 64, which is a magnetic element that generates a strong magnetic Barkhausen effect, and a coil 65 wound around the magnetic double metal wire 64. The magnetic sensors 61, 62, and 63 serve as concrete examples of a magnetic field detecting part.

[0049] The magnetic double metal wire 64 is a thin wire-like ferromagnetic material characterized by uniaxial anisotropy. In the magnetic double metal wire 64, the coercive force at the axis is stronger than the coercive force at the outer circumference, resulting in the magnetization direction at the axis remaining constant unless a strong magnetic field is generated outside the magnetic sensor. The magnetization direction at the outer circumference is inverted by the action of a relatively weak magnetic field generated outside the magnetic sensor. When a relatively weak external magnetic field is applied to the magnetic double metal wire 64, only the magnetization direction of the outer circumference can be changed and maintained.Furthermore, when the magnetization direction of the outer circumference of the magnetic double-metal wire 64 is changed to coincide with the magnetization direction of the axis, the magnetization direction is suddenly reversed due to the strong magnetic Barkhausen effect. When the magnetization direction of the outer circumference of the magnetic double-metal wire 64 is changed to be opposite to the magnetization direction of the axis, the magnetization direction is also suddenly reversed. The electromotive force generated by the sudden reversal of the magnetic field generates a positive or negative pulse in the coil 65, depending on the magnetization direction.

[0050] Each of the magnetic sensors 61, 62 and 63 is, as shown in Fig. 2, is fixed within the housing 41 so that it connects one end of the magnetic double metal wire 64 to the support member 66 and the other end to the wall of the housing 41. In addition, each of the magnetic sensors 61, 62, and 63 is placed so that the magnetic double metal wire 64 lies in the direction of the magnetic field generated by each of the magnets 51, 52, 53, and 54. In addition, the magnetic sensors 61, 62, and 63, as shown in Fig. 1, mounted in this order in a left-hand direction so that they are located along the outer circumference of the moving part 43 at intervals of 120 degrees around the rotating shaft 32.

[0051] When the moving part 43 rotates according to the rotation of the rotating shaft 32, the magnets 51, 52, 53, and 54 alternately reach the magnetic sensors 61, 62, and 63. Positive or negative detection pulses are outputted by the magnetic sensors 61, 62, and 63 in turn. Specifically, when the magnet 51 reaches the magnetic sensor 61 with the N pole at the front, and the magnetization direction of the magnetic sensor 61 is reversed by the magnetic field generated by the magnet 51, a positive detection pulse is outputted by the magnetic sensor 61. The same occurs when the magnet 53 reaches the magnetic sensor 61. In addition, when the magnet 52 with the S pole at the front reaches the magnetic sensor 61 and the magnetization direction of the magnetic sensor 61 is reversed by the magnetic field generated by the magnet 51, a negative detection pulse is generated by the magnetic sensor 61.The same thing happens when magnet 54 reaches magnetic sensor 61. If the magnets reach magnetic sensor 61 with the same poles twice or more consecutively, the magnetization direction of magnetic sensor 61 is not inverted the second or subsequent time. If the magnetization direction of magnetic sensor 61 is not inverted due to the presence of a magnetic field with the same rotation direction, neither a positive-going detection pulse nor a negative-going detection pulse is generated by magnetic sensor 61. The same applies to magnetic sensors 62 and 63. A detailed description of the case where the magnetization direction of the magnetic sensor is not inverted due to the presence of a magnetic field with the same rotation direction is given in the section dedicated to the initial situation of the present development.

[0052] In addition, the support 66 is located within the housing 41. The support 66 is, for example, attached to a wall of the housing 41. The support 66 is, as in Fig. 1, is disc-shaped and has, as shown in Fig. 2, in the center of which is the opening 67, which movably accommodates the rotating shaft 32. The rotation detection circuit 68 and the connecting element 69 are located on the support 66. The coil 65 of each of the magnetic sensors 61, 62, and 63 is electrically connected to the rotation detection circuit 68 located on the base 66. The rotation speed detection value stored in the memory section 82 of the rotation detection circuit 68 can be exported to the connecting element 69 via the connecting cable 70. (Rotation detector circuit)

[0053] The Fig. Figure 3 illustrates the internal structure of the rotation detection circuit 68. The rotation detection circuit 68 is a circuit for detecting the rotation direction and rotation speed of the moving part 43. The rotation detection circuit 68 includes the decision part 81, the storage part 82, and the power supply circuit 83 serving as a power source. Specifically, the rotation detection circuit 68 is a concrete example of a motion detection circuit.

[0054] The decision part 81 determines the rotation direction and rotation speed of the moving part 43 based on the number of the last detection pulse, the rotation direction indication, and the rotation speed detection value described below, which is stored in the storage part 82 in accordance with the obtained results. In particular, the decision part 81 is a concrete example of an operation processing part and an update processing part.

[0055] The storage part 82 consists of a non-volatile data memory which stores the number of the last detection pulse, the rotation direction indication and the detection value of the rotation speed, ie the information required to carry out the decision process by the decision part 81.

[0056] The power supply circuit 83 includes a rectifier, a DC voltage circuit, and other elements that generate DC current based on the detection pulses generated by the magnetic sensors 61, 62, and 63 and serve as a power source for the decision part 81 and the storage part 82. The decision part 81 and the storage part 82 are controlled by the voltage generated by the power supply circuit 83e. Thus, the rotation detection device 31 can be activated without a power supply. (Progress of the rotation detection process)

[0057] The Fig. 4 to 6 show the rotation detection process performed by the rotation detector circuit 68. The Fig. 7 to 9 illustrate the relationship between the movements of the moving part 43 and the information used to perform the rotation detection process.

[0058] During the rotation detection process, the decision part 81 assigns corresponding numbers to the positive-going detection pulses and the negative-going detection pulses generated by the magnetic sensors 61, 62, and 63. Namely, as mentioned above, the magnets 51, 52, 53, and 54 are mounted in this order at intervals of 90 degrees in the left direction so that the poles on the front side thereof are the N pole, the S pole, the N pole, and the S pole, and the magnetic sensors 61, 62, and 63 are mounted in this order at intervals of 120 degrees in the right direction.With this position of the magnets 51, 52, 53, and 54 and the magnetic sensors 61, 62, and 63, when the moving part 43 rotates in the clockwise direction, positive or negative pulses are continuously outputted sequentially by the three magnetic sensors 61, 62, and 63 (the corresponding positive and negative detection pulses outputted during this time are not always generated in the same order). Thus, when the moving part 43 subsequently rotates in the clockwise direction, negative or positive detection pulses are sent sequentially by the three magnetic sensors 61, 62, and 63 (the corresponding negative and positive detection pulses outputted during this time are not always generated in the same order). The result is a constant pattern of a total of six detection pulses, which have different sources and can be positively or negatively directed.The decision part 81 assigns the numbers “1”, “2”, “3”, “4”, “5”, “6” to the six detection pulses that form this pattern.

[0059] Thus, when the moving part 43 rotates in the clockwise direction, the magnet 51 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a positive detection pulse is generated by the magnetic sensor 61; then, the magnet 54 reaches the magnetic sensor 62, the magnetization direction of the magnetic sensor 62 is inverted, and a negative detection pulse is generated by the magnetic sensor 62; then, the magnet 53 reaches the magnetic sensor 63, the magnetization direction of the magnetic sensor 63 is inverted, and a positive detection pulse is generated by the magnetic sensor 63. Subsequently, assuming that the moving part 43 continues to rotate in the clockwise direction, the magnet 52 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a negative detection pulse is generated by the magnetic sensor 61.Then, magnet 51 reaches magnetic sensor 62, the magnetization direction of magnetic sensor 62 is inverted, and a positive detection pulse is generated by magnetic sensor 62. Then, magnet 54 reaches magnetic sensor 63, the magnetization direction of magnetic sensor 63 is inverted, and a negative detection pulse is generated by magnetic sensor 63. As a result, a pulse pattern is formed consisting of a positive detection pulse output by magnetic sensor 61, a negative detection pulse sent by magnetic sensor 62, a positive detection pulse from magnetic sensor 63, a negative detection pulse generated by magnetic sensor 61, a positive detection pulse output by magnetic sensor 62, and a negative detection pulse from magnetic sensor 63.Subsequently, the decision part 81 assigns the number “1” to the positive detection pulse sent by the magnetic sensor 61, the number “2” to the negative detection pulse received from the magnetic sensor 62, the number “3” to the positive detection pulse outputted by the magnetic sensor 63, the number “4” to the negative detection pulse generated by the magnetic sensor 61, the number “5” to the positive detection pulse coming from the magnetic sensor 62, and the number “6” to the negative detection pulse outputted by the magnetic sensor 63.

[0060] The decision part 81 identifies the inputs of the rotation detector circuit 68 to which the magnetic sensors 61, 62 and 63 are connected, detects the parameters of the detection pulses output by the magnetic sensors 61, 62 and 63, and, based on this information, distinguishes the six detection pulses coming from different sources and being either positively or negatively directed, and assigns them the above-mentioned numbers.

[0061] In the description of one embodiment of the present invention, it is explained that the rotation detection device has three magnetic sensors. However, the present invention relates to a rotation detection device that can have n magnetic sensors (n is equal to or higher than 3). If the present invention relates to a rotation detection device equipped with n magnetic sensors, 2n detection pulses are output from different sources and with either a negative or a positive direction, resulting in a pattern of detection pulses assigned the numbers 1, 2, 3,..., n, n+1, n+2, n+3,..., 2n.

[0062] When starting the rotation detecting device 31, the decision part 81 performs a process for determining the initial parameters of the rotational movement. First, the decision part 81 stores the initial value (for example, 0, or another value indicative of the rotational speed of the rotating shaft 32 immediately before starting the rotation detecting device 31) of the rotational speed, which will be explained below, in the storage part 82. Then, the decision part 81 stores the number of the first detection pulse output by any one of the magnetic sensors 61, 62, and 63 at the start of the rotation of the moving part 43 as the number of the last pulse described below, in the storage part 82.Next, the decision part 81 subtracts the number of the last detection pulse (the number of the detection pulse output first) stored in the storage part 82 from the number of the detection pulse output twice by any one of the magnetic sensors 61, 62, and 63, and decides whether the obtained value is positive or negative. Then, if this obtained value is positive, the decision part 81 decides that the moving part 43 is rotating in the right direction and stores "right direction" in the storage part 82 as the rotation direction information described below. If the above-mentioned obtained value is negative, the decision part 81 decides that the moving part 43 is rotating in the left direction and stores "left direction" in the storage part 82 as the rotation direction information.Subsequently, the decision part 81 stores the above-mentioned detection pulse number that was output twice as the last detection pulse in the storage part 82 and updates the detection pulse number. Then, the decision part 81 increases the obtained detection value of the rotation speed by 1 when the moving part 43 rotates in the right direction, or decreases the obtained detection value of the rotation speed by 1 when the moving part 43 rotates in the left direction, thus updating the detection value of the rotation speed.

[0063] Subsequently, the decision part 81 starts the rotation detection process, which is Fig. 4 to 6. The rotation detection process generally proceeds as follows. The rotation detection process is executed upon receipt of a detection pulse output by any one of the magnetic sensors 61, 62, and 63 after completion of the above-mentioned determination of the initial parameters. Subsequently, the most recent detection pulse now output by any one of the magnetic sensors 61, 62, and 63 is referred to as the "current detection pulse," and the number assigned to the current detection pulse is called the "current detection pulse number." Furthermore, the current detection pulse generated by any one of the magnetic sensors 61, 62, and 63, based on the time at which it is output, is called the "last detection pulse," and the number assigned to the last detection pulse is called the "last detection pulse number."At the time when the current detection pulse is output, the number of the last detection pulse, the rotation direction indication indicating the rotation direction of the moving part 43 at the time when the last detection pulse is output, and the detection value of the rotation speed indicating the rotation speed of the moving part 43 at the time when the last detection pulse is output are stored in the storage part 82.

[0064] The last detection pulse number is the number assigned to one of the six detection pulses, which can have different sources and be negative or positive. Therefore, the amount of data required to store the last detection pulse number in memory section 82 is 3 bits.

[0065] In addition, there can be four types of information indicating the rotation direction: "right direction," "left direction," "unidentified," and "unrecognized inversion." "Right direction" indicates that the moving part 43 is rotating in the right direction, while "left direction" indicates that the moving part 43 is rotating in the left direction. Furthermore, "unidentified" indicates a situation (hereinafter referred to as the "unidentified state") where it is not possible to decide whether the moving part 43 is rotating in the right direction or the left direction. "Unrecognized inversion" indicates a situation (hereinafter referred to as the "unrecognized inversion state") where the moving part 43 changes its rotation direction (inverts), and it is unknown in which direction the moving part 43 is now rotating.Thus, since the rotation direction indication can have four values, the amount of data required to store the number of the last detection pulse in the memory section 82 is 2 bits.

[0066] The rotation speed detection value is a value indicating the rotation speed of the moving part 43. The rotation detection device 31 according to the present embodiment is basically capable of detecting a change in the rotation speed of the moving part 43 in 30-degree increments. During the rotation detection process, the rotation speed detection value is increased by 1 when the moving part 43 rotates 30 degrees in the right direction or decreased by 1 when the moving part 43 rotates 30 degrees in the left direction. The rotation detection device 31 can detect when the moving part 43 makes more than one revolution, i.e., rotates multiple times. The amount of data required to store the rotation speed detection value in the storage part 82 depends on the maximum detectable rotation speed of the moving part 43 preset in the rotation detection device 31.

[0067] During the rotation detection process, when the detection pulse is output by one of the magnetic sensors 61, 62 and 63, the decision part 81 detects the pulse source and whether it is a positive or negative pulse, and sets the number of the current detection pulse.

[0068] Next, the decision section 81 subtracts the number of the last detection pulse stored in the storage section 82 from the current pulse number, thus obtaining the pulse comparison value. The "pulse comparison value" refers to a value obtained by subtracting the number of the last detection pulse from the number of the current detection pulse. Specifically, if the value obtained by subtracting the number of the last detection pulse from the number of the current detection pulse is negative, the value obtained by adding 6 (2n) to this value is used as the pulse comparison value.

[0069] Then, the decision part 81 determines the rotation direction of the moving part 43 at the time when the current detection pulse is output based on the pulse comparison value and the rotation direction information stored in the storage part 82, and decides whether it corresponds to the “right direction”, “left direction”, an “unidentified state” or an “unrecognized inversion”.

[0070] Subsequently, the decision part 81 determines the change value of the rotation speed of the moving part 43 in the period between the current detection pulse and the last detection pulse based on the pulse comparison value and the rotation direction information stored in the storage part 82. Hereinafter, the change value of the rotation speed of the moving part 43 determined in the period between the current detection pulse and the last detection pulse is called the “rotation change value”.

[0071] The standard information that determines the relationship between the pulse comparison value, the last rotation direction information, the current rotation direction information, and the current rotation change value is preliminarily stored in the storage section 82. The decision section 81 determines the rotation direction information and the rotation change value at the time the current detection pulse is output based on the rotation direction information stored in the storage section 82 and the pulse comparison value, as well as the standard information. The standard information includes, for example, as shown in Fig. 7 to 9, the pulse comparison value, and, if the rotation detection device is equipped with three sensors, the last rotation direction information, the current rotation direction information, and the rotation change value are displayed. The standard information is essentially a part of the computer program used to perform the rotation detection process. Each value of the standard information is set as a constant in this computer program.

[0072] Subsequently, the decision part 81 overwrites the number of the last detection pulse stored in the memory part 82 with the number of the current detection pulse, thus updating the number of the last detection pulse stored in the memory part 82. Furthermore, the decision part 81 overwrites the rotation direction information stored in the memory part 82 with the information indicating the rotation direction at the time the current detection pulse is transmitted, thus updating the rotation direction information stored in the memory part 82.

[0073] The general course of the rotation detection process is described above. A detailed description of the rotation detection process will be given using concrete examples and the Fig. 4 to 9 explained.

[0074] First, four normal processes A to D are described. Normal processes are processes for determining the rotation direction and rotation speed of the moving part 43 since no detection pulse is missing. (Normal Process A)

[0075] For example, the moving part 43 rotates clockwise, the magnet 52 reaches the magnetic sensor 63, the magnetization direction of the magnetic sensor 63 is inverted, and a negative-directed detection pulse is generated by the magnetic sensor 63. No detection pulse is missing so far. As a result, in the memory part 82, the number of the last detection pulse is updated to "6," and the rotation direction is updated to "clockwise." In this state, the moving part 43 rotates approximately 30 degrees clockwise, the magnet 51 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a positive-directed detection pulse is generated by the magnetic sensor 61.

[0076] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 61 and the pulse is positive-going, the decision part 81 decides that the current detection pulse number is "1." Then, since the current detection pulse number is "1" and the last detection pulse number is "6," the decision part 81 subtracts the last detection pulse number from the current detection pulse number and decides that the pulse comparison value is 1 (although subtracting "6" from "1" results in -5, the value obtained by adding 6 to this value is used as the pulse comparison value if the subtraction results in a negative result).Then, if the pulse comparison value is 1 and the rotation direction is “right direction” (step S1: NO, step S3: YES, step S4: YES, step S5: YES in . Fig. 4), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse is output is “right direction” and that the rotation change value is 1 (step S6 in Fig. 4, the process number P1 in Fig. 7). Then, the decision part 81 updates the number of the last detection pulse to "1", increases the detection value of the rotation speed by 1, and leaves the rotation direction indication "right direction" unchanged. (Normal Process B)

[0077] For example, the moving part 43 last rotates in the left direction, the magnet 54 reaches the magnetic sensor 62, the magnetization direction of the magnetic sensor 62 is inverted, and a negative-directed detection pulse is generated by the magnetic sensor 62. Up to this point, no detection pulse has been missed. As a result, in the memory part 82, the number of the last detection pulse is updated to "2" and the rotation direction is updated to "left direction." In this state, the moving part 43 rotates approximately 30 degrees in the left direction, the magnet 51 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a positive-directed detection pulse is generated by the magnetic sensor 61.

[0078] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 61 and the pulse is positive-going, the decision part 81 decides that the current detection pulse number is "1." Then, since the current detection pulse number is "1" and the last detection pulse number is "2," the decision part 81 subtracts the last detection pulse number from the current detection pulse number and decides that the pulse comparison value is 5 (although subtracting "2" from "1" results in -1, the value obtained by adding 6 to this value is used as the pulse comparison value when the subtraction result is a negative value).Then, since the pulse comparison value is 5 and the rotation direction indication is “left direction” (step S1: NO, step S3: YES, step S4: YES, step S5: NO, step S7: YES, in . Fig. 4), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse is output is “left direction” and the rotation change value is -1 (step S6 in Fig. 4, process number P2 in Fig. 7). Then, the decision part 81 updates the number of the last detection pulse to "5", decreases the detection value of the rotation speed by 1, and leaves the rotation direction indication "left direction" unchanged. (Normal Process C)

[0079] For example, if the moving part 43 last rotates in a right direction, the magnet 51 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a positive detection pulse is generated by the magnetic sensor 61. Up to this point, no detection pulse has been missed. As a result, in the memory part 82, the number of the last detection pulse is updated to "1" and the rotation direction is updated to "right direction." In this position, the moving part 43 changes the rotation direction from right to left and rotates approximately 120 degrees in the left direction. When the moving part 43 rotates approximately 120 degrees in the left direction, the magnets 51, 52, and 53 first reach the magnetic sensors 61, 63, and 62 in the above-described order. However, the magnetization directions of the magnetic sensors 61, 63 and 62 are not inverted due to the generation of magnetic fields with the same direction of rotation.Subsequently, when the magnet 54 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted and a negatively directed detection pulse is generated by the magnetic sensor 61.

[0080] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 61 and the pulse is negative, the decision part 81 decides that the number of the current detection pulse is "4." Then, since the number of the current detection pulse is "4" and the number of the last detection pulse is "1," the decision part 81 subtracts the number of the last detection pulse from the number of the current detection pulse and decides that the pulse comparison value is 3. Then, since the pulse comparison value is 3 and the rotation direction indication is "right direction" (step S1: NO, step S3: NO, step S12: YES in Fig. 4, Step S13: YES in Fig. 5), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse is output is “left direction” and that the rotation change value is equal to -3 (step S14 in Fig. 5, process number P3 in Fig. 7). Then, the decision part 81 updates the number of the last detection pulse to "4", decreases the detection value of the rotation speed by 3, and updates the rotation direction indication to "left direction".

[0081] Although the rotation detecting device according to the present invention is equipped with three magnetic sensors, the present invention can be applied to a rotation detecting device having n magnetic sensors (n is equal to or greater than 3). When the present invention is applied to a rotation detecting device equipped with n magnetic sensors, the number of magnetic sensors whose magnetization directions are not inverted due to the generation of magnetic fields having the same rotation direction when the moving part changes the rotation direction from right to left and continues to rotate in the left direction will be n, and thus the pulse comparison value will be n and the rotation change value will be -n. (Normal Process D)

[0082] For example, the moving part 43 last rotates in the left direction, the magnet 51 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a positive-directed detection pulse is generated by the magnetic sensor 61. Up to this point, no detection pulse has been missed. As a result, in the memory part 82, the number of the last detection pulse is updated to "1" and the rotation direction is updated to "left direction." In this state, the moving part 43 changes the rotation direction from left to right and rotates approximately 120 degrees in the right direction. When the moving part 43 rotates approximately 120 degrees in the clockwise direction, the magnets 51, 54 and 53 sequentially reach the magnetic sensors 61, 62 and 63 in the above-mentioned order, but the magnetization directions of the magnetic sensors 61, 62 and 63 are not inverted due to the generation of magnetic fields with the same rotation direction.Subsequently, when the magnet 52 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a negative detection pulse is generated by the magnetic sensor 61.

[0083] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 61 and the direction of the detection pulse is negative, the decision part 81 decides that the number of the current detection pulse is "4." Then, since the number of the current detection pulse is "4" and the number of the last detection pulse is "1," the decision part 81 subtracts the number of the last detection pulse from the number of the current detection pulse and decides that the pulse comparison value is 3. Then, since the pulse comparison value is 3 and the rotation direction indication is "left direction" (step S1: NO, step S3: NO, step S12: YES in Fig. 4, Step S13: YES in Fig. 5), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse is output is “right direction” and that the rotation change value is 3 (step S14 in Fig. 5, process number P4 in Fig. 7). Then, the decision part 81 updates the number of the last detection pulse to "4", increases the detection value of the rotation speed by 3, and updates the rotation direction indication to "right direction".

[0084] When the present invention is applied to a rotation detecting device equipped with n magnetic sensors (n is 3 or more), the number of the magnetic sensors whose magnetization directions are not inverted due to the generation of magnetic fields having the same rotation direction when the moving part changes the rotation direction from left to right and further rotates in the right direction will be n, and the pulse comparison value will therefore be n and the rotation change value will be n.

[0085] Subsequently, twelve missing complementary processes A to L are described. Missing complementary processes are processes that serve to determine the rotation direction and the rotation speed of the moving part 43 in the case where a detection pulse is missing. (Missing complementary process A)

[0086] For example, the moving part 43 last rotates in a clockwise direction, the magnet 51 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a positive-going detection pulse is generated by the magnetic sensor 61. Up to this point, no detection pulse has been missed. As a result, in the memory part 82, the number of the last detection pulse is updated to "1," and the rotation direction is updated to "rightward." In this state, the moving part 43 rotates approximately 60 degrees in a clockwise direction. When the moving part 43 rotates approximately 60 degrees in a clockwise direction, the magnet 54 reaches the magnetic sensor 62, and the magnetization direction of the magnetic sensor 62 is inverted. Nevertheless, a detection pulse that should have been output by the magnetic sensor 62 is missing.Subsequently, the magnet 53 reaches the magnetic sensor 63, the magnetization direction of the magnetic sensor 63 is inverted, and a positive-directed detection pulse is generated by the magnetic sensor 63.

[0087] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 63 and the pulse is positively directed, the decision part 81 decides that the number of the current detection pulse is "3." Then, since the number of the current detection pulse is "3" and the number of the last detection pulse is "1," the decision part 81 subtracts the number of the last detection pulse from the number of the current detection pulse and decides that the pulse comparison value is 2. Then, since the pulse comparison value is 2 and the rotation direction indication is "right direction" (step S1: NO, step S3: NO, step S12: NO in Fig. 4, Step S18: YES, Step S19: NO, Step S21: NO in Fig. 6), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse is output is “not identified” and outputs -1 as the first adjustment value for the rotation change value (step S22 in Fig. 6, process number P5 in Fig. 8). Subsequently, the decision part 81 updates the number of the last detection pulse to "3", decreases the detection value of the rotation speed by 1, and updates the rotation direction indication to "unidentified".

[0088] Specifically, in this process, -1 is the first adjustment value for the rotation change value required to effectively and properly perform the rotation detection process in the current embodiment of the rotation detection device according to the present invention. When the present invention is applied to a rotation detection device equipped with n magnetic sensors, the first adjustment value is -(n-1) / 2. (Missing complementary process B)

[0089] For example, the moving part 43 last rotates in the left direction, the magnet 53 reaches the magnetic sensor 62, the magnetization direction of the magnetic sensor 62 is inverted, and a positive-directed detection pulse is generated by the magnetic sensor 62. Up to this point, no detection pulse has been missed. As a result, in the memory part 82, the number of the last detection pulse is updated to "5" and the rotation direction is updated to "left direction." In this state, the moving part 43 changes the rotation direction from left to right and rotates approximately 150 degrees in the right direction. When the moving part 43 rotates approximately 150 degrees in the clockwise direction, the magnets 53, 52 and 51 reach the magnetic sensors 62, 63 and 61 in the above-mentioned order, but the magnetization directions of the magnetic sensors 62, 63 and 61 are not inverted due to the generation of magnetic fields with the same rotation direction.Subsequently, when the magnet 54 reaches the magnetic sensor 62, the magnetization direction of the magnetic sensor 62 is inverted. Nevertheless, a detection pulse that should have been output by the magnetic sensor 62 is missing. Subsequently, the magnet 53 reaches the magnetic sensor 63, the magnetization direction of the magnetic sensor 63 is inverted, and a positive-directed detection pulse is generated by the magnetic sensor 63.

[0090] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 63 and the pulse is positive-going, the decision part 81 decides that the current detection pulse number is "3." Then, since the current detection pulse number is "3" and the last detection pulse number is "5," the decision part 81 subtracts the last detection pulse number from the current detection pulse number and decides that the pulse comparison value is 4. (Although subtracting "5" from "3" results in -2, the value obtained by adding 6 to this value is used as the pulse comparison value when the subtraction result is a negative value.)Then, if the pulse comparison value is 4 and the rotation direction indication is “left direction” (step S1: NO, step S3: NO, step S12: NO in . Fig. 4, Step S18: YES, Step S19: NO, Step S21: NO in Fig. 6), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse is output is “not identified” and outputs 1 as the first adjustment value for the rotation change value (step S22 in Fig. 6, process number P8 in Fig. 8). Subsequently, the decision part 81 updates the number of the last detection pulse to "3", increases the detection value of the rotation speed by 1, and updates the rotation direction indication to "unidentified".

[0091] Specifically, in this process, the value 1 set for the rotation change value is the first adjustment value required for effective and proper performance of the rotation detection process in the current embodiment of the rotation detection device according to the present invention. When the present invention is applied to a rotation detection device equipped with n magnetic sensors, the first adjustment value is (n-1) / 2. (Missing complementary process C)

[0092] For example, the moving part 43 last rotates approximately 60 degrees in the clockwise direction. In the meantime, the magnet 54 reaches the magnetic sensor 62, and the magnetization direction of the magnetic sensor 62 is inverted. However, a detection pulse that should have been output by the magnetic sensor 62 is missing. Subsequently, the magnet 53 reaches the magnetic sensor 63, the magnetization direction of the magnetic sensor 63 is inverted, and a positive-directed detection pulse is generated by the magnetic sensor 63. As a result, in the memory part 82, the number of the last detection pulse is updated to "3" and the rotation direction is updated to "unidentified." In this state, the moving part 43 rotates approximately 30 degrees in the clockwise direction, the magnet 52 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a negative-directed detection pulse is generated by the magnetic sensor 61.

[0093] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 61 and the direction of the detection pulse is negative, the decision part 81 decides that the number of the current detection pulse is "4." Then, since the number of the current detection pulse is "4" and the number of the last detection pulse is "3," the decision part 81 subtracts the number of the last detection pulse from the number of the current detection pulse and decides that the pulse comparison value is 1. Then, since the pulse comparison value is 1 and the rotation direction indication is "not identified" (step S1: NO, step S3: YES, step S4: NO, step S9: NO in Fig. 4), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse is output is “right direction” and outputs 4 as the second adjustment value for the rotation change value (step S11 in Fig. 4, process number P9 in Fig. 8). Subsequently, the decision part 81 updates the number of the last detection pulse to "4", increases the detection value of the rotation speed by 4, and updates the rotation direction indication to "right direction".

[0094] Specifically, in this process, the value 4 specified for the rotation change value is the second adjustment value required for effective and proper performance of the rotation detection process in the current embodiment of the rotation detection device according to the present invention. When the present invention is applied to a rotation detection device equipped with n magnetic sensors, the second adjustment value is (n+5) / 2. (Missing complementary process D)

[0095] For example, the moving part 43 last rotates approximately 60 degrees in the counterclockwise direction. In the meantime, the magnet 54 reaches the magnetic sensor 62, and the magnetization direction of the magnetic sensor 62 is inverted. However, a detection pulse that should have been output by the magnetic sensor 62 is missing. Subsequently, the magnet 51 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a positive-directed detection pulse is generated by the magnetic sensor 61. As a result, in the memory part 82, the number of the last detection pulse is updated to "1" and the rotation direction is updated to "unidentified." In this state, the moving part 43 rotates approximately 30 degrees in the counterclockwise direction, the magnet 52 reaches the magnetic sensor 63, the magnetization direction of the magnetic sensor 63 is inverted, and a negative-directed detection pulse is generated by the magnetic sensor 63.

[0096] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 63 and the direction of the detection pulse is negative, the decision part 81 decides that the number of the current detection pulse is "6." Then, since the number of the current detection pulse is "6" and the number of the last detection pulse is "1," the decision part 81 subtracts the number of the last detection pulse from the number of the current detection pulse and decides that the pulse comparison value is 5. Then, since the pulse comparison value is 5 and the rotation direction indication is "not identified" (step S1: NO, step S3: YES, step S4: NO, step S9: NO in Fig. 4), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse is output is “left direction” and outputs -4 as the second adjustment value for the rotation change value (step S11 in Fig. 4, process number P10 in Fig. 8). Then, the decision part 81 updates the number of the last detection pulse to "6," decreases the detection value of the rotation speed by 4, and updates the rotation direction indication to "left direction."

[0097] Specifically, in this process, the value -4 specified for the rotation change value is the second adjustment value required for effective and proper performance of the rotation detection process in the current embodiment of the rotation detection device according to the present invention. When the present invention is applied to a rotation detection device equipped with n magnetic sensors, the second adjustment value is -(n+5) / 2.

[0098] Next, the adjustment of the rotation speed detection value of the moving part 43 using the above-mentioned first adjustment value and the second adjustment value will be described. Specifically, at the time when a detection pulse is output by one of the magnetic sensors 61, 62, and 63 after a detection pulse has been missed, the rotation direction of the moving part 43 is determined to be "unidentified," and the first adjustment value (-1 or 1), which depends on whether the rotation direction information currently stored in the storage part 82 is "right direction" or "left direction," is set for the rotation change value. Subsequently, the rotation change value for which the first adjustment value was set is added to the rotation speed detection value to adjust it. The above-mentioned missing complementary processes A and B are examples of this adjustment.Subsequently, at the time when the detection pulse is generated by one of the magnetic sensors 61, 62, and 63 after the rotation direction of the moving part 43 is determined as "right direction" or "left direction," the second adjustment value (4 or -4) is determined for the rotation change value according to the decision of "right direction" or "left direction." Then, the rotation change value for which the second adjustment value has been specified is added to the rotation speed detection value to adjust it. The above-mentioned missing complementary processes C and D are examples of this adjustment. After these two adjustments are made, the rotation speed detection value indicates the correct rotation speed of the moving part 43. Thus, the effect of a missing detection pulse is eliminated. (Missing complementary process E)

[0099] For example, the moving part 43 last rotates approximately 60 degrees in the left direction. In the meantime, the magnet 54 reaches the magnetic sensor 62, and the magnetization direction of the magnetic sensor 62 is inverted. However, a detection pulse that should have been output by the magnetic sensor 62 is missing. Subsequently, the magnet 51 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a positive-going detection pulse is generated by the magnetic sensor 61. As a result, in the memory part 82, the number of the last detection pulse is updated to "1" and the rotation direction is updated to "unidentified." In this state, the moving part 43 changes the rotation direction from left to right and rotates approximately 120 degrees in the right direction.When the moving part 43 rotates approximately 120 degrees clockwise, the magnets 51, 54, and 53 reach the magnetic sensors 61, 62, and 63 in the above-described order. However, the magnetization directions of the magnetic sensors 61, 62, and 63 are not reversed due to the generation of magnetic fields with the same rotation direction. Subsequently, when the magnet 52 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is reversed, and a negative-directed detection pulse is generated by the magnetic sensor 61.

[0100] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 61 and the direction of the detection pulse is negative, the decision part 81 decides that the number of the current detection pulse is "4." Then, since the number of the current detection pulse is "4" and the number of the last detection pulse is "1," the decision part 81 subtracts the number of the last detection pulse from the number of the current detection pulse and decides that the pulse comparison value is 3. Then, since the pulse comparison value is 3 and the rotation direction indication is "not identified" (step S1: NO, step S3: NO, step S12: YES in Fig. 4, Step S13: NO, Step S15: NO in Fig. 5), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse was output is an “unrecognized inversion” and outputs 0 for the rotation change value (step S17 in Fig. 5, process number P12 in Fig. 8). Subsequently, the decision part 81 updates the number of the last detection pulse to "4," leaves the detection value of the rotation speed unchanged, and updates the rotation direction indication to "undetected inversion."

[0101] Particularly in this process, when the present invention is applied to a rotation detecting device equipped with n magnetic sensors, the rotation change value is 0. (Missing complementary process F)

[0102] For example, after the rotation direction is not identified due to a missing detection pulse, the moving part 43 changes the rotation direction from left to right and rotates approximately 120 degrees in the clockwise direction. When the moving part 43 rotates approximately 120 degrees in the clockwise direction, the magnets 51, 54, and 53 sequentially reach the magnetic sensors 61, 62, and 63 in the above-described order, but the magnetization directions of the magnetic sensors 61, 62, and 63 are not inverted due to the generation of magnetic fields with the same rotation direction. Subsequently, when the magnet 52 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a negative-direction detection pulse is generated by the magnetic sensor 61. As a result, in the memory part 82, the number of the last detection pulse is updated to “4” and the rotation direction is updated to “unrecognized inversion”.In this state, the moving part 43 rotates approximately 30 degrees in the right direction, the magnet 51 reaches the magnetic sensor 62, the magnetization direction of the magnetic sensor 62 is inverted, and a positive-directed detection pulse is generated by the magnetic sensor 62.

[0103] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 62 and the pulse is positively directed, the decision part 81 decides that the number of the current detection pulse is "5." Then, since the number of the current detection pulse is "5" and the number of the last detection pulse is "4," the decision part 81 subtracts the number of the last detection pulse from the number of the current detection pulse and decides that the pulse comparison value is 1. Then, since the pulse comparison value is 1 and the rotation direction indication is "undetected inversion" (step S1: NO, step S3: YES, step S4: NO, step S9: YES in Fig. 4), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse was output was “right direction” and outputs 1 as the third adjustment value for the rotation change value (step S10 in Fig. 4, process number P13 in Fig. 8). Then, the decision part 81 updates the number of the last detection pulse to "5," increases the detection value of the rotation speed by 1, and updates the rotation direction indication to "right direction."

[0104] Specifically, in this process, the value 1 specified for the rotation change value is the third adjustment value required for effective and proper performance of the rotation detection process in the current embodiment of the rotation detection device according to the present invention. When the present invention is applied to a rotation detection device equipped with n magnetic sensors, the third adjustment value is (n-1) / 2. (Missing complementary process G)

[0105] For example, after the rotation direction is not identified due to a missing detection pulse, the moving part 43 changes the rotation direction from right to left and rotates approximately 120 degrees in the counterclockwise direction. During the time when the moving part 43 rotates approximately 120 degrees in the counterclockwise direction, the magnets 51, 52, and 53 sequentially reach the magnetic sensors 62, 61, and 63 in the above-described order. However, the magnetization directions of the magnetic sensors 62, 61, and 63 are not inverted due to the generation of magnetic fields with the same rotation direction. Subsequently, when the magnet 54 reaches the magnetic sensor 62, the magnetization direction of the magnetic sensor 62 is inverted, and a negative-direction detection pulse is generated by the magnetic sensor 62.As a result, the number of the last detection pulse in the memory section 82 is updated to "2," and the rotation direction is updated to "undetected inversion." In this state, the moving part 43 rotates approximately 30 degrees in the counterclockwise direction. The magnet 51 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a positive-directed detection pulse is generated by the magnetic sensor 61.

[0106] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 61 and the pulse is positive-going, the decision part 81 decides that the current detection pulse number is "1." Then, since the current detection pulse number is "1" and the last detection pulse number is "2," the decision part 81 subtracts the last detection pulse number from the current detection pulse number and decides that the pulse comparison value is 5 (although subtracting "2" from "1" results in -1, the value obtained by adding 6 to this value is used as the pulse comparison value if the subtraction result is a negative value).Then, since the momentum comparison value is 5 and the rotation direction indication is “undetected inversion” (step S1: NO, step S3: YES, step S4: NO, step S9: YES in . Fig. 4), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse is output is “left direction” and sets -1 as the third adjustment value for the rotation change value (step S10 in Fig. 4, process number P14 in Fig. 8). Then, the decision part 81 updates the number of the last detection pulse to "1", decreases the detection value of the rotation speed by 1, and updates the rotation direction indication to "left direction".

[0107] Specifically, in this process, the value 1 specified for the rotation change value is the third adjustment value required for effective and proper performance of the rotation detection process in the current embodiment of the rotation detection device according to the present invention. When the present invention is applied to a rotation detection device equipped with n magnetic sensors, the third adjustment value is -(n-1) / 2.

[0108] Next, the adjustment of the rotation speed detection value of the moving part 43 using the above-mentioned third adjustment value will be described. Namely, at the time when the detection pulse is output by one of the magnetic sensors 61, 62, and 63 after a detection pulse is missed, the rotation direction of the moving part 43 is determined to be "unidentified," and the first adjustment value (-1 or 1) is set for the rotation change value depending on whether the rotation direction information currently stored in the storage part 82 is "right direction" or "left direction." Subsequently, the rotation change value for which the first adjustment value was set is added to the rotation speed detection value, thereby adjusting the rotation speed detection value. The missing complementary processes A and B are examples of such value adjustment.Subsequently, after judging that the moving part 43 is in an undetected inversion state at the time when the detection pulse is output by any one of the magnetic sensors 61, 62, and 63, 0 is set for the rotation change value, and thus the rotation change value remains unchanged. Subsequently, after judging the rotation direction of the moving part 43 at the time when the detection pulse is output by any one of the magnetic sensors 61, 62, and 63 as "right direction" or "left direction," the third adjustment value (1 or -1) is set for the rotation change value according to whether it was "right direction" or "left direction." Subsequently, the rotation change value for which the third adjustment value is set is added to the rotation speed detection value, thereby adjusting the rotation speed detection value.The missing complementary processes F and G are examples of such value adjustment. After these two adjustments have been made, the rotation speed detection value indicates the correct rotation speed of the moving part 43. Thus, the effect of a missing detection pulse is eliminated. (Missing complementary process H)

[0109] For example, after the rotation direction is not identified due to a missing detection pulse, the moving part 43 changes the rotation direction from left to right and rotates approximately 120 degrees in the clockwise direction. During the time when the moving part 40 rotates approximately 120 degrees in the clockwise direction, the magnets 51, 54, and 53 successively reach the magnetic sensors 61, 62, and 63, but the magnetization directions of the magnetic sensors 61, 62, and 63 are not inverted due to the generation of magnetic fields with the same rotation direction. Subsequently, when the magnet 52 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a negative-direction detection pulse is generated by the magnetic sensor 61. As a result, in the memory part 82, the number of the last detection pulse is updated to "4," and the rotation direction is updated to "undetected inversion."In this state, the moving part 43 changes its rotation direction from left to right and rotates approximately 120 degrees in the counterclockwise direction. During the time when the moving part 43 rotates approximately 120 degrees in the counterclockwise direction, the magnets 52, 53, and 54 sequentially reach the magnetic sensors 61, 63, and 62. However, the magnetization directions of the magnetic sensors 61, 63, and 62 are not reversed due to the generation of magnetic fields with the same rotation direction. Subsequently, when the magnet 51 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is reversed, and a positive-going detection pulse is generated by the magnetic sensor 61.

[0110] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 61 and the pulse is positive-going, the decision part 81 decides that the current detection pulse number is "1." Then, since the current detection pulse number is "1" and the last detection pulse number is "4," the decision part 81 subtracts the last detection pulse number from the current detection pulse number and decides that the pulse comparison value is 3 (although subtracting "4" from "1" results in -3, the value obtained by adding 6 to this value is used as the pulse comparison value if the subtraction result is a negative value).Then, since the momentum comparison value is 3 and the rotation direction indication is “undetected inversion” (step S1: NO, step S3: NO, step S12: YES in . Fig. 4, Step S13: NO, Step S15: YES in Fig. 5), the decision part 81 decides that the rotation direction of the moving part 43 has not been identified at the time when the current detection pulse is outputted and outputs 0 for the rotation change value (step S16 in Fig. 5, process number P15 in Fig. 8). Subsequently, the decision part 81 updates the number of the last detection pulse to "1", leaves the detection value of the rotation speed unchanged, and updates the rotation direction indication to "unidentified".

[0111] Particularly in this process, when the present invention is applied to a rotation detecting device equipped with n magnetic sensors, the rotation change value is 0. (Missing complementary process I)

[0112] For example, the moving part 43 last rotates approximately 60 degrees in the right direction. Meanwhile, the magnet 53 reaches the magnetic sensor 62, the magnetization direction of the magnetic sensor 62 is inverted, and a positive-directed detection pulse is generated by the magnetic sensor 62. As a result, in the memory part 82, the number of the last detection pulse is updated to "5" and the rotation direction is updated to "right direction." Subsequently, the magnet 52 reaches the magnetic sensor 63, and the magnetization direction of the magnetic sensor 63 is inverted, but the detection pulse that should have been generated by the magnetic sensor 63 is missing. Then, the moving part 43 changes the rotation direction from right to left and rotates approximately 120 degrees in the left direction.At the time when the moving part 43 rotates approximately 120 degrees in the counterclockwise direction, the magnets 52, 53, and 54 sequentially reach the magnetic sensors 63, 62, and 61. However, the magnetization directions of the magnetic sensors 63, 62, and 61 are not inverted due to the generation of magnetic fields with the same rotation direction. Subsequently, when the magnet 51 reaches the magnetic sensor 63, the magnetization direction of the magnetic sensor 63 is inverted, and a positive-biased detection pulse is generated by the magnetic sensor 63.

[0113] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 63 and the pulse is positive-going, the decision part 81 decides that the current detection pulse number is "3." Then, since the current detection pulse number is "3" and the last detection pulse number is "5," the decision part 81 subtracts the last detection pulse number from the current detection pulse number and decides that the pulse comparison value is 4. (Although subtracting "5" from "3" results in -2, the value obtained by adding 6 to this value is used as the pulse comparison value if the subtraction result is a negative value.)Then, since the pulse comparison value is 4 and the rotation direction indication is “right direction” (step S1: NO, step S3: NO, step S12: NO in . Fig. 4, Step S18: YES, Step S19: NO, Step S21: YES in Fig. 6), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse is output is “left direction” and that the rotation change value is -2 (step S20 in Fig. 6, process number P18 in Fig. 8). Then, the decision part 81 updates the number of the last detection pulse to "3", decreases the detection value of the rotation speed by 2, and updates the rotation direction indication to "left direction".

[0114] Particularly in this process, when the present invention is applied to a rotation detecting device equipped with n magnetic sensors, the rotation change value is -(n-1). (Missing complementary process J)

[0115] For example, the moving part 43 last rotates approximately 60 degrees in the right direction. In the meantime, the magnet 52 reaches the magnetic sensor 63, and the magnetization direction of the magnetic sensor 63 is inverted, but the detection pulse that should have been generated by the magnetic sensor 63 is missing. Subsequently, the magnet 51 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a positive-going detection pulse is generated by the magnetic sensor 61. As a result, in the memory part 82, the number of the last detection pulse is updated to "1," and the rotation direction is updated to "unidentified." In this state, the moving part 43 changes the rotation direction from right to left and rotates approximately 150 degrees in the left direction.At the time when the moving part 43 rotates approximately 150 degrees in the counterclockwise direction, the magnets 51, 52, and 53 successively reach the magnetic sensors 61, 63, and 62. However, the magnetization directions of the magnetic sensors 61, 63, and 62 are not inverted due to the generation of magnetic fields with the same rotation direction. Subsequently, when the magnet 54 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, but the detection pulse that should have been generated by the magnetic sensor 61 is missing. Subsequently, when the magnet 51 reaches the magnetic sensor 63, the magnetization direction of the magnetic sensor 63 is inverted, and a positive-directed detection pulse is generated by the magnetic sensor 63.

[0116] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 63 and the pulse is positively directed, the decision part 81 decides that the number of the current detection pulse is "3." Then, since the number of the current detection pulse is "3" and the number of the last detection pulse is "1," the decision part 81 subtracts the number of the last detection pulse from the number of the current detection pulse and decides that the pulse comparison value is 2. Then, since the pulse comparison value is 2 and the rotation direction indication is "not identified" (step S1: NO, step S3: NO, step S12: NO in Fig. 4, Step S18: NO, Step S23: NO in Fig. 6), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse is output is “left direction” and that the rotation change value is -1 (step S25 in Fig. 6, process number P19 in Fig. 9). Then, the decision part 81 updates the number of the last detection pulse to "3", decreases the detection value of the rotation speed by 1, and updates the rotation direction indication to "left direction".

[0117] In particular, in this process, when the present invention is applied to a rotation detecting device equipped with n magnetic sensors, the rotation change value is -(n-1-(n-1) / 2). (Missing complementary process K)

[0118] For example, after the rotation direction is not identified due to a missing detection pulse, the moving part 43 changes the rotation direction from left to right and rotates approximately 120 degrees in the clockwise direction. During the time when the moving part 43 rotates approximately 120 degrees in the clockwise direction, the magnets 54, 53, and 52 sequentially reach the magnetic sensors 61, 62, and 63. However, the magnetization directions of the magnetic sensors 61, 62, and 63 are not inverted due to the generation of magnetic fields with the same rotation direction. Subsequently, when the magnet 51 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a positive-going detection pulse is generated by the magnetic sensor 61. As a result, in the memory part 82, the number of the last detection pulse is updated to “1”, and the rotation direction is updated to “unrecognized inversion”.Subsequently, the moving part 43 rotates approximately 60 degrees in the clockwise direction. Meanwhile, when the magnet 54 reaches the magnetic sensor 62, the magnetization direction of the magnetic sensor 62 is inverted. However, a detection pulse that should have been output by the magnetic sensor 62 is missing. Subsequently, when the magnet 54 reaches the magnetic sensor 63, the magnetization direction of the magnetic sensor 63 is inverted, and a positive-directed detection pulse is generated by the magnetic sensor 63.

[0119] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 63 and the pulse is positively directed, the decision part 81 decides that the number of the current detection pulse is "3." Then, since the number of the current detection pulse is "3" and the number of the last detection pulse is "1," the decision part 81 subtracts the number of the last detection pulse from the number of the current detection pulse and decides that the pulse comparison value is 2. Then, since the pulse comparison value is 2 and the rotation direction indication is "undetected inversion" (step S1: NO, step S3: NO, step S12: NO in Fig. 4, Step S18: NO, Step S23: YES in Fig. 6), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse is output is “not identified” and outputs -1 as the fourth adjustment value for the rotation change value (step S24 in Fig. 6, process number P21 in Fig. 8). Subsequently, the decision part 81 updates the number of the last detection pulse to "3", decreases the detection value of the rotation speed by 1, and updates the rotation direction indication to "unidentified".

[0120] When the present invention is applied to a rotation detecting device equipped with n magnetic sensors, the value -1 is set as the fourth adjustment value for the rotation change value. (Missing complementary process L)

[0121] For example, the moving part 43 finally rotates approximately 30 degrees in the right direction, the magnet 51 reaches the magnetic sensor 61, the magnetization direction of the magnetic sensor 61 is inverted, and a positive-direction detection pulse is generated by the magnetic sensor 61. As a result, in the memory part 82, the number of the last detection pulse is updated to "1" and the rotation direction is updated to "right direction." Then, the moving part 43 changes the rotation direction from right to left and rotates approximately 120 degrees in the left direction. Meanwhile, the magnets 51, 52, and 53 sequentially reach the magnetic sensors 61, 63, and 62. However, the magnetization directions of the magnetic sensors 61, 63, and 62 are not inverted due to the generation of magnetic fields with the same rotation direction.Subsequently, magnet 54 reaches magnetic sensor 61, the magnetization direction of magnetic sensor 61 is inverted, but the detection pulse that should have been generated by magnetic sensor 61 is missing. Subsequently, moving part 43 changes its rotation direction from left to right and rotates approximately 120 degrees in the clockwise direction. Meanwhile, magnets 54, 53, and 52 successively reach magnetic sensors 61, 62, and 63, but the magnetization directions of magnetic sensors 61, 62, and 63 are not inverted due to the generation of magnetic fields with the same rotation direction. Subsequently, magnet 51 reaches magnetic sensor 61, the magnetization direction of magnetic sensor 61 is inverted, and a positive-direction detection pulse is generated by magnetic sensor 61.

[0122] The rotation detection process in this case is as follows. Since the source of the current detection pulse is the magnetic sensor 61 and the pulse is positively directed, the decision part 81 decides that the number of the current detection pulse is "1." Then, since the number of the current detection pulse is "1" and the number of the last detection pulse is "1," the decision part 81 subtracts the number of the last detection pulse from the number of the current detection pulse and decides that the pulse comparison value is 0. Then, since the pulse comparison value is 0 and the rotation direction indication is "right direction" (step S1: YES in Fig. 4), the decision part 81 decides that the rotation direction of the moving part 43 at the time when the current detection pulse is output is “right direction” and that the rotation change value is 0 (step S2 in Fig. 4, process number P25 in Fig. 8). Then, the decision part 81 updates the number of the last detection pulse to "1", does not change the detection value of the rotation speed, and leaves the rotation direction indication unchanged as "right direction".

[0123] Particularly in this process, when the present invention is applied to a rotation detecting device equipped with n magnetic sensors, the rotation change value is 0.

[0124] Twelve missing complementary processes have been described above. Some other missing complementary processes not described above are described in Fig. 8 or Fig. 9. These undescribed missing complementary processes can be found in the Fig. 8 or Fig. 9 can be easily understood after understanding the course of the missing complementary processes described above. (Faulty process)

[0125] If the pulse comparison value is 1 and the rotation direction indication is "left direction," or if the pulse comparison value is 5 and the rotation direction indication is "right direction," the decision part 81 decides that an error has occurred. This may mean, for example, that the rotation detection process needs to be stopped and the rotation direction and rotation speed of the moving part 43 need to be corrected by other means. Considering the other correction means used when an error occurs, explanations of the processes are omitted here.

[0126] As described above, with the rotation detection device 31 in the embodiment according to the present invention, in the absence of a complementary process, the rotation direction and rotation speed of the moving part 43 can be detected without having to determine the detection pulse output twice. This reduces the amount of data required to perform the processes for determining the rotation direction and rotation speed of the moving part 43, and thus reduces the storage area of the memory element occupied by this process.

[0127] Some aspects of the rotation detecting device 31 in the embodiment according to the present invention will be described in more detail when comparing it with conventional rotation detecting devices. Namely, the first example of the above-mentioned missing complementary process in the conventional rotation detecting device 300 (the rotation detecting device described in the related art) and the above-described missing complementary processes A and C in the rotation detecting device 31 in the embodiment according to the present invention are consistent with each other with respect to the movement of the moving part.The second example of the above-mentioned missing complementary process in the conventional rotation detecting device 300 and the above-described missing complementary processes B and C in the rotation detecting device 31 in the embodiment according to the present invention differ in the direction of rotation, but agree with each other in terms of the movement of the moving part. The third example of the above-mentioned missing complementary process in the conventional rotation detecting device 300 and the above-described missing complementary process F in the rotation detecting device 31 in the embodiment according to the present invention agree with each other in terms of the movement of the moving part.

[0128] Compared to the missing complementary processes performed in the rotation detection device according to the invention, the missing complementary processes performed in a conventional rotation detection device store information indicating whether a detection pulse was missing. If a detection pulse was missing, this information is used to subtract the number of the detection pulse that was previously output twice from the number of the current detection pulse. The obtained value is used to calculate the correct rotation change value of the moving part. Thus, in the conventional rotation detection device 300, the detection pulse that was output twice must be stored and updated using the number of the last detection pulse when a detection pulse is output.Therefore, since the number of the detection pulse that was issued twice needs to be saved and updated, appropriate memory area must be reserved to store the variable imported into the memory element.

[0129] In the missing complementary processes in the rotation detection device according to the invention, "right direction", "left direction", "unidentified", and "undetected inversion" are stored as the rotation direction indications. The missing complementary processes in the rotation detection device according to the invention include processes that indicate the rotation direction as "unidentified" when it is detected that a detection pulse is missing; then, the rotation change value of the moving part 43 is adjusted using the first adjustment value when the rotation direction indication is "unidentified"; and the rotation change value of the moving part 43 is changed using the second adjustment value when the rotation direction indication is changed from "unidentified" to "right direction" or "left direction", whereby the correct rotation change value of the moving part 43 is calculated.The missing complementary processes in the rotation detecting device according to the invention also include processes that change the rotation direction indication from "unidentified" to "undetected inversion" when the moving part 43, which has been put into an unidentified state by a missing detection pulse, changes the rotation direction; the rotation change value of the moving part 43 is set to 0 when the rotation direction indication is "undetected inversion"; the rotation change value of the moving part 43 is adjusted using the third adjustment value when the rotation direction indication is changed from "undetected inversion" to "right direction" or "left direction", whereby the correct rotation change value of the moving part 43 is calculated. In addition, if a detection pulse is missing in the time when the moving part 43, which is in the state of unrecognized inversion, rotates to the right or left, orWhen a detection pulse is missing immediately after the moving part 43, which was in the state of undetected inversion, changes its rotation direction to the right or left, the rotation change value of the moving part 43 is adjusted using the fourth adjustment value, whereby the correct rotation change value of the moving part 43 is calculated.

[0130] In the present invention, the first adjustment value is -1 or 1, the second adjustment value is 4 or -4, and the third adjustment value is 1 or -1. The first adjustment value, the second adjustment value, and the third adjustment value are constants determined according to the numbers of the magnetic sensors. The fourth adjustment value is 1 or -1. This value is also a constant. Therefore, these adjustment values can be set as fixed values in the computer program to perform missing complementary processes. In other words, in the rotation detecting device 31 according to the present invention, it is not necessary to reserve a memory area in the memory element for storing any variables to be imported in order to store the first adjustment value, the second adjustment value, the third adjustment value, and the fourth adjustment value.Therefore, in comparison with a conventional rotation detecting device, in the rotation detecting device 31 in the embodiment of the present invention, the storage area for storing variables to be imported in the storage element can be reduced by the amount of data (for example, 3 bits) required for storing the number of the detection pulse outputted twice.

[0131] In particular, although, in the invention described above, a rotation detecting device having four (two pairs of) magnets 51, 52, 53 and 54 is exemplified, the rotation detecting device may have two (one pair), six (three pairs) or more magnets.

[0132] Furthermore, although in the invention described above, a rotation detecting device having four magnets 51, 52, 53, and 54 mounted at intervals of 90 degrees and three magnetic sensors 61, 62, and 63 mounted at intervals of 120 degrees is exemplified, the present invention is not limited thereto. For example, as shown in Fig. 13, the four magnets can be installed at intervals of 90 degrees, and the three magnetic sensors can be mounted at intervals of 30 degrees in a part near the moving part. In other words, it is different from the rotation detector device 300 used in Fig. 13, it is possible to update a missing complementary process without using the detection pulse that was output twice, thus reducing the storage area of the memory element used to store missing complementary processes. Thus, the missing complementary processes described in the present invention can be used instead of the missing complementary processes occurring in the conventional rotation detecting device 300, with the same configuration of the magnets and magnetic sensors used in the conventional rotation detecting device 300.

[0133] Furthermore, although in the invention described above, a rotation detecting device having the magnets 51, 52, 53, and 54 located in the moving part 43 and the magnetic sensors 61, 62, and 63 located in the periphery of the moving part 43 is exemplified, the present invention is not limited thereto. For example, as in the rotation detecting device 100 shown in Fig. 10, the magnetic sensors 61, 62, and 63 are mounted in the moving part 43, and the magnets 51, 52, 53, and 54 are mounted in the periphery of the moving part 43. In this case, the magnetic sensors 61, 62, and 63 change their position together with the moving part 43, and the magnets 51, 52, 53, and 54 remain immobile.

[0134] Furthermore, although in the invention described above, a rotation detecting device having the magnets 51, 52, 53, and 54 and the magnetic sensors 61, 62, and 63 mounted so that the magnets 51, 52, 53, and 54 are located opposite the magnetic sensors 61, 62, and 63 on the periphery of the moving part 43 during rotation of the moving part 43 is exemplified, the present invention is not limited thereto. For example, as in the rotation detecting device 110 shown in Fig. 11, the magnets 112 and the magnetic sensors 113 are mounted so that each of the four magnets 112 (in Fig. 11 only two are shown) during the rotation of the moving part 111 relative to the magnetic sensors 113 parallel to the rotation axis of the moving part 111.

[0135] Furthermore, although the invention described above cites a rotation detection device for detecting the rotation direction and rotation speed of an object as an example, the present invention is not limited thereto. For example, the present invention may be applied to the circulating motion detection device 120 shown in Fig. 12, refer to a rotation detecting device in which a plurality of magnet pairs 122 are located in the moving part 121, which perform a circulating movement together with the corresponding object, and there are three or more magnetic sensors 123 located in the periphery of the moving part 121.

[0136] Furthermore, the present invention includes various embodiments within the scope of the summary of the invention or within the scope of the inventive ideas formulated in the claims. The entire specification and the motion detection device containing such variants are also included in the technical idea of the present invention. [LEGEND] 31, 100, 100, 300 Rotation detector device (motion detector device) 32, 301 rotating shaft (a specific object) 43, 111, 121, 312 movement part 51, 52, 53, 54, 112, 122 Magnet (magnetic field generating part) 61, 62, 63, 113, 123 Magnetic sensor (magnetic field detector part) 64 magnetic double metal wire 65 coil 66 carriers 68 Rotation detector circuit (motion detector circuit) 81 Decision part (operation processing part, update processing part) 82 storage part 83 Supply voltage circuit 120 circulating motion detector device (motion detector device)

Claims

[1] A motion detector device (31, 100, 100, 120, 300) for detecting the rotational movement or circulating movement of an object (32, 301), comprising the following components: a moving part (43, 111, 121, 312) which rotates or circulates in accordance with the rotational movement or the circulating movement of the object (32, 301); at least one pair of magnetic field generating parts (51, 52, 53, 54, 112, 122) which are located in the moving part (43, 111, 121, 312) and generate opposing magnetic fields; n magnetic field detection parts (61, 62, 63, 113, 123) (n is equal to 3 or more) located in a vicinity of the moving part (43, 111, 121, 312), each of which outputs a positive detection pulse as a result of a change in a magnetization direction when one of the one pair of magnetic field generating parts (51, 52, 53, 54, 112, 122) approaches, and each of which outputs a negative detection pulse as a result of a change in the magnetization direction when another of the one pair of magnetic field generating parts (51, 52, 53, 54, 112, 122) approaches; and a motion detector circuit (68) comprising a storage part (82), an operation processing part (81) and an update processing part, which receives detection pulses output from each of the magnetic field detector parts (61, 62, 63, 113, 123) and determines the state of the rotational movement or the circulating movement of the object (32, 301) on the basis of the received detection pulses, at least one pair of magnetic field generating parts (51, 52, 53, 54, 112, 122) and n magnetic field detecting parts (61, 62, 63, 113, 123) mounted in such a way that detection pulses having either a positive or a negative direction are continuously output by n magnetic field detecting parts (61, 62, 63, 113, 123) when the moving part (43, 111, 121, 312) rotates in one direction (the positive or negative directions of the corresponding n detection pulses generated during this time do not always have the same order), and positive or negative detection pulses are continuously output when the moving part (43, 111, 121, 312) rotates in the other direction (the positive or negative directions of the corresponding n Detection pulses generated during this time do not always have the same order), so that a constant pattern of a total of 2n detection pulses, which are emitted in different combinations and from different sources,arises, the operation processing part (81) assigns the numbers 1, 2,..., n, n+1, n+2,..., 2n to 2n to the detection pulses forming the above-mentioned pattern, the storage part (82) stores the number of the last detection pulse output by one of the n magnetic field detection parts (61, 62, 63, 113, 123), the information about the direction of movement, information as to whether it is one direction or the other, whether the direction has not been identified, and whether there is an inversion to an unidentified state (hereinafter referred to as unrecognized inversion), the direction of movement of the moving part (43, 111, 121, 312) at the time when the last detection pulse was output, and the detection value of the movement speed indicating a speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when this last detection pulse was output, the operation processing part (81) decides, based on the difference between the number of the current detection pulse output by one of the n magnetic field detection parts (61, 62, 63, 113, 123) and the last detection pulse, the number of which has been stored in the memory part (82), as well as based on the information on the direction of movement and the detection value of the movement speed stored in the memory part (82), in which direction the movement part (43, 111, 121, 312) rotates, whether the direction has not been identified and whether an undetected inversion of the direction of movement of the movement part (43, 111, 121, 312) is taking place at the time when this current detection pulse is output, and decides or determines the speed of the rotational movement or the circulating movement of the movement part (43, 111, 121, 312) at the time, when this current detection pulse is output, the update processing part updates the number of the last detection pulse stored in the storage part (82) based on the number of the current detection pulse, updates the information on the direction of movement stored in the storage part (82) based on the decision of the operation processing part (81) and the direction of movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output, and updates the detection value of the movement speed stored in the storage part (82) based on the decision of the operation processing part (81) and the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output. [2] A motion detector device (31, 100, 100, 120, 300) for detecting the rotational movement or circulating movement of an object (32, 301), comprising the following components: a moving part (43, 111, 121, 312) which rotates or circulates in accordance with the rotational movement or the circulating movement of the object (32, 301); at least one pair of magnetic field generating parts (51, 52, 53, 54, 112, 122) which are located in a vicinity of the moving part (43, 111, 121, 312) and generate opposing magnetic fields; n magnetic field detection parts (61, 62, 63, 113, 123) (n is equal to 3 or more) located in the moving part (43, 111, 121, 312), each of which outputs a positive detection pulse as a result of a change in a magnetization direction when one of the pair of magnetic field generating parts (51, 52, 53, 54, 112, 122) approaches, and each of which outputs a negative detection pulse as a result of a change in the magnetization direction when another of the pair of magnetic field generating parts (51, 52, 53, 54, 112, 122) approaches; and a motion detector circuit (68) comprising a storage part (82), an operation processing part (81) and an update processing part, which receives detection pulses output from each of the magnetic field detector parts (61, 62, 63, 113, 123) and determines the state of the rotational movement or the circulating movement of the object (32, 301) on the basis of the received detection pulses, at least one pair of magnetic field generating parts (51, 52, 53, 54, 112, 122) and n magnetic field detecting parts (61, 62, 63, 113, 123) mounted in such a way that detection pulses having either a positive or a negative direction are continuously output by n magnetic field detecting parts (61, 62, 63, 113, 123) when the moving part (43, 111, 121, 312) rotates in one direction (the positive or negative directions of the corresponding n detection pulses generated during this time do not always have the same order), and positive or negative detection pulses are continuously output when the moving part (43, 111, 121, 312) rotates in the other direction (the positive or negative directions of the corresponding n Detection pulses generated during this time do not always have the same order), so that a constant pattern of a total of 2n detection pulses, which are emitted in different combinations and from different sources,arises, the operation processing part (81) assigns the numbers 1, 2,..., n, n+1, n+2,..., 2n to 2n to the detection pulses forming the above-mentioned pattern, the storage part (82) stores the number of the last detection pulse output by one of the n magnetic field detection parts (61, 62, 63, 113, 123), the information about the direction of movement, information as to whether it is one direction or the other, whether the direction has not been identified, and whether there is an inversion to an unidentified state (hereinafter referred to as unrecognized inversion), the direction of movement of the moving part (43, 111, 121, 312) at the time when the last detection pulse was output, and the detection value of the movement speed indicating a speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when this last detection pulse was output, the operation processing part (81) decides, based on the difference between the number of the current detection pulse output by one of the n magnetic field detection parts (61, 62, 63, 113, 123) and the last detection pulse, the number of which has been stored in the memory part (82), as well as based on the information on the direction of movement and the detection value of the movement speed stored in the memory part (82), in which direction the movement part (43, 111, 121, 312) rotates, whether the direction has not been identified and whether an undetected inversion of the direction of movement of the movement part (43, 111, 121, 312) is taking place at the time when this current detection pulse is output, and decides or determines the speed of the rotational movement or the circulating movement of the movement part (43, 111, 121, 312) at the time, when this current detection pulse is output,The update processing section updates the number of the last detection pulse stored in the memory section (82) based on the number of the current detection pulse; updates the information about the direction of movement stored in the memory section (82) based on the decision of the operation processing section (81) and the direction of movement of the moving part (43, 111, 121, 312) at the time the current detection pulse is output; and updates the detection value of the movement speed stored in the memory section (82) based on the decision of the operation processing section (81) and the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time the current detection pulse is output. [3] Motion detector device (31, 100, 100, 120, 300) according to claim 1 or 2, characterized by , that the operation processing part (81) calculates the comparison value obtained by subtracting the number of the last detection pulse from the number of the current detection pulse (if the obtained value is a negative value, this value is determined by adding 2n to the obtained value), decides, if the comparison value is 1 and the information about the direction of movement indicates one direction, that the moving part (43, 111, 121, 312) rotates in this direction at the time when the current detection pulse is output, and that a change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is +1, decides, if the comparison value is 2n-1 and the information about the direction of movement indicates the other direction, that the moving part (43, 111, 121, 312) rotates in this other direction at the time when the current detection pulse is output, and that the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is -1, decides, if the comparison value is n and the information about the direction of movement indicates one direction, that the moving part (43, 111, 121, 312) rotates in the other direction at the time when the current detection pulse is output, and that the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is -n, decides, if the comparison value is n and the information about the direction of movement indicates the other direction, that the moving part (43, 111, 121, 312) rotates in one direction at the time when the current detection pulse is output, and that the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is +n, decides, if the comparison value is 2 and the information about the direction of movement indicates one direction, that the direction of movement of the moving part (43, 111, 121, 312) was not detected at the time when the current detection pulse is output, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output, in the amount of -(n-1) / 2, decides, if the comparison value is n-1 and the information about the direction of movement indicates one direction, that the direction of movement of the moving part (43, 111, 121, 312) was not detected at the time when the current detection pulse is output, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output, in the amount of -(n-1) / 2, decides, if the comparison value is 2n-2 and the information about the direction of movement indicates the other direction, that the direction of movement of the moving part (43, 111, 121, 312) was not detected at the time when the current detection pulse is output, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output, in the amount of (n-1) / 2, decides, if the comparison value is n+1 and the information about the direction of movement indicates the other direction, that the direction of movement of the moving part (43, 111, 121, 312) was not detected at the time when the current detection pulse is output, and determines the change value of the speed of the moving part (43, 111, 121, 312) of the rotational movement or the circulating movement at the time when the current detection pulse is output, in the amount of (n-1) / 2, decides, if the comparison value is 1 and the information about the direction of movement is unknown, that the direction of movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is one direction, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output, in the amount of (n+5) / 2, and decides, if the comparison value is 2n-1 and the information about the direction of movement is unknown, that the direction of movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is the other direction, and determines the value of change of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output as - (n+5) / 2. [4] Motion detector device (31, 100, 100, 120, 300) according to claim 3 characterized by , that the operation processing part (81) decides, when the comparison value is n and the information about the direction of movement is unknown, that there is an undetected inversion at the time when the current detection pulse is output, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output to be 0, decides, if the comparison value is 1 and the information about the direction of movement indicates an undetected inversion, that the direction of movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is one direction, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output, in the amount of (n-1) / 2, decides, if the comparison value is 2n-1 and the information about the direction of movement indicates an undetected inversion, that the direction of movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is the other direction, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output, in the amount of -(n-1) / 2, and decides, if the comparison value is n and the information about the direction of movement indicates an undetected inversion, that the direction of movement of the moving part (43, 111, 121, 312) was not detected at the time when the current detection pulse is output, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output to be 0. [5] Motion detector device (31, 100, 100, 120, 300) according to claim 4 characterized by , that the operation processing part (81) decides, if the comparison value is 2 and the information about the direction of movement indicates an undetected inversion, that the direction of movement of the moving part (43, 111, 121, 312) has not been detected at the time when the current detection pulse is output, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output to be -1, decides, if the comparison value is n-1 and the information about the direction of movement indicates an undetected inversion, that the direction of movement of the moving part (43, 111, 121, 312) was not detected at the time when the current detection pulse is output, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output, to be -1, decides, if the comparison value is 2n-2 and the information about the direction of movement indicates an undetected inversion, that the direction of movement of the moving part (43, 111, 121, 312) was not detected at the time when the current detection pulse is output, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output to be 1, and decides, if the comparison value is n+1 and the information about the direction of movement indicates an undetected inversion, that the direction of movement of the moving part (43, 111, 121, 312) was not detected at the time when the current detection pulse is output, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output to be 1. [6] Motion detector device (31, 100, 100, 120, 300) according to claim 5 characterized by , that the operation processing part (81) decides, when the comparison value is n-1 and the information about the direction of movement indicates the other direction, that the direction of movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is one direction, and that the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is n-1, decides, if the comparison value is n+1 and the information about the direction of movement indicates one direction, that the direction of movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is the other direction, and that the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is -(n-1), decides, if the comparison value is n-1 and the information about the direction of movement is unknown, that the direction of movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is the other direction, and determines the value of change in the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output, in the amount of -(n-1-(n-1) / 2), and decides, when the comparison value is n+1 and the information about the direction of movement is unknown, that the direction of movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is one direction, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output as n-1-(n-1) / 2. [7] Motion detector device (31, 100, 100, 120, 300) according to claim 6 characterized by , that the operation processing part (81) decides, if the comparison value is 0 and the information about the direction of movement indicates the one direction, that the direction of movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is this one direction, and that the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is 0, decides, if the comparison value is 0 and the information about the direction of movement indicates the other direction, that the direction of movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is this other direction, and that the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is 0, decides, if the comparison value is 0 and the information about the direction of movement is unknown, that the direction of movement of the moving part (43, 111, 121, 312) has not been detected at the time when the current detection pulse is output, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output to be 0, and decides, if the comparison value is 0 and the information about the direction of movement indicates an unrecognized inversion, that the direction of movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output is an unrecognized inversion, and determines the change value of the speed of the rotational movement or the circulating movement of the moving part (43, 111, 121, 312) at the time when the current detection pulse is output to be 0. [8] A motion detector device (31, 100, 100, 120, 300) according to claim 1 or 2, characterized by that each of the magnetic field detector parts (61, 62, 63, 113, 123) is equipped with a magnetic element which generates a strong magnetic Barkhausen effect, and with a coil (65) wound around the magnetic element.

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