JP2010243152A - Encoder and electromechanical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an encoder of high-resolution, having a simple structure. <P>SOLUTION: The encoder 300 includes: a rotating disk 310; optical element arrays 311 to 314 comprising slits or reflective plates equidistantly provided on the rotating disk; light emitting parts 321 to 324 irradiating the optical element arrays with light; and light receiving parts 371 to 374 receiving the light from the individual optical elements of the optical element arrays and outputting rectangular light receiving signals. The n (n is an integer of 2 or more) pieces of the optical element arrays having distances from the center of the rotating disk different from one another are arranged in n arrays along the circumference. The n sets of the optical element arrays include identical number m (m is an integer of 2 or above) optical elements. The n sets of the light emitting parts and light receiving parts are arranged, corresponding to the n sets of the optical element arrays. The n set of optical element arrays and the n sets of the light emitting parts and light receiving parts are arranged so that the phases of n light receiving signals generated at the n sets of light receiving parts are sequentially shifted by π/n, where the phase difference of one period of the individual light receiving signals is defined as 2π. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an encoder.

  The encoder is used for controlling a motor, for example. At this time, in order to control the motor at an extremely low rotation, it is preferable to increase the resolution of the encoder and increase the number of pulses to be generated. In a conventional encoder, a slit is used to generate a pulse (for example, Patent Document 1), and in order to increase the resolution, the slit is 2 pulses / rotation, 4, 8,... 256 / rotation from the inside. An encoder arranged in a base code string is known (for example, Non-Patent Document 1).

Japanese Patent Laid-Open No. 06-269147

ISBN 4-7898-4150-2 ("Basics and Applications of Small DC Motors", Transistor Technology Editor, CQ Publisher) P159-160

  However, the conventional encoder has a problem that the slit pattern becomes complicated when trying to cope with high resolution. Further, there is a problem that the resolution is regulated by the width of the slit.

  An object of the present invention is to solve at least a part of the problems described above and to realize a high-resolution encoder with a simple configuration.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
An encoder, which is a rotating disk, an optical element array composed of slits or reflectors provided at equal intervals on the rotating disk, a light emitting unit that emits light to the optical element array, and the optical element array A light receiving portion that receives light that passes through or reflects each of the optical elements and outputs a rectangular light receiving signal, and the optical element rows are different in distance from the center of the rotating disk. N rows are arranged along the circumference (n is an integer of 2 or more), and the n sets of optical element rows each include an equal number of m (m is an integer of 2 or more) optical elements. The light emitting unit and the light receiving unit are arranged in n sets corresponding to the n sets of optical element arrays, and when the phase difference of one period of each received light signal is defined as 2π, the n sets The optical element array and the n sets of light emitting and receiving portions are n Phase of the n light receiving signal generated by the light receiving portion are arranged sequentially shifted by [pi / n, encoders.
According to this application example, the pattern of the slit or the reflector is not complicated. Therefore, it is possible to realize a high-resolution encoder with a simple configuration.

[Application Example 2]
The encoder according to Application Example 1, wherein the n sets of optical element arrays are arranged at positions sequentially shifted by π / (m · n) in mechanical angles measured on the rotating disk.
According to this application example, the light emitting unit and the light receiving unit can be arranged along a straight line in the radial direction of the rotating disk.

[Application Example 3]
In the encoder described in Application Example 1 or Application Example 2,
n is an encoder of 3 or more.
According to this application example, it is easy to determine forward rotation and reverse rotation.

[Application Example 4]
A control unit that controls an electric power supplied to the electromagnetic coil by using a magnet, an electromagnetic coil, the encoder according to any one of application examples 1 to 3, and an output of the encoder, the electromechanical device. And an electromechanical device.
According to this application example, the motor can be rotated at an extremely low rotation.

  The present invention can be realized in various forms. For example, in addition to an encoder, the present invention can be realized in various forms such as an electromechanical apparatus and a method for increasing the resolution of the encoder.

It is explanatory drawing which shows typically the structure of the motor system which concerns on a 1st Example. It is explanatory drawing which shows an example of the control block of a motor system. It is explanatory drawing which shows the structure of an encoder. It is explanatory drawing which shows an example of the circuit structure of a synthetic | combination pulse signal generation part. It is a timing chart of a synthetic pulse signal generation part. It is explanatory drawing which shows an example of a rotation direction signal generation part. It is a timing chart in a rotation direction signal generation part. It is explanatory drawing which shows the circuit structure of the encoder 300 in a 2nd Example. It is explanatory drawing which shows an example of the synthetic | combination pulse signal production | generation part in a 2nd Example. It is explanatory drawing which shows an example of the rotation direction signal generation part in a 2nd Example. It is a timing chart of the logic operation part in a 2nd Example. It is explanatory drawing which shows the circuit structure of the encoder 300 in a 3rd Example. It is explanatory drawing which shows the synthetic | combination pulse signal production | generation part of a 3rd Example. It is a timing chart of the logic operation part of the logic operation part of the encoder of a 3rd Example. It is explanatory drawing which shows the circuit structure of the encoder 300 in a 4th Example. It is explanatory drawing which shows the projector using the motor by the example of application of this invention. It is explanatory drawing which shows the fuel cell type mobile telephone using the motor by the example of application of this invention. It is explanatory drawing which shows the electric bicycle (electric assisted bicycle) as an example of the moving body using the motor / generator by the example of application of this invention. It is explanatory drawing which shows an example of the robot using the motor by the example of application of this invention.

[First embodiment]
FIG. 1 is an explanatory diagram schematically showing the configuration of the motor system according to the first embodiment. The motor system includes a motor 100, a speed increaser 200, an encoder 300, and a load 400. The motor 100 includes a drive shaft 110, a magnet 120, an electromagnetic coil 130, and a magnetic sensor 140. There is no particular limitation on the configuration of the magnet that generates the rotational force of the motor 100 and the configuration of the electromagnetic coil, and various configurations can be used. The drive shaft 110 is connected to a rotor (not shown) provided with a magnet 120. The magnetic sensor 140 is used to detect the relative position (phase) of the magnet 120 with respect to the electromagnetic coil 130, and for example, a Hall IC can be used. However, the magnetic sensor 140 can be omitted.

  The drive shaft 110 of the motor 100 is connected to the input stage of the speed increaser 200. The speed increaser 200 includes a planetary gear mechanism 210. The planetary gear mechanism 210 includes a sun gear 211 (also referred to as “sun gear 211”), a planetary gear 212 (also referred to as “planet gear 212”), and an outer gear 215 (also referred to as “outer ring gear 215”). A planetary carrier (not shown). Specifically, the drive shaft 110 of the motor 100 is connected to the outer gear 215 (also referred to as “outer ring gear 215”) of the planetary gear mechanism 210. The output of the speed increaser 200 is connected to the encoder 300. Specifically, the sun gear 211 of the planetary gear mechanism 210 is connected to the encoder 300. In the planetary gear mechanism 210 of this embodiment, the outer gear 215 is an input, the sun gear 211 is an output, and the planetary carrier is fixed. If the number of teeth of the sun gear 211 is S and the number of teeth of the outer gear 215 is G, the reduction ratio is input / output = −S / G, and does not depend on the number of teeth of the planetary gear 212. In general, since the number of teeth G of the outer gear 215 is larger than the number of teeth S of the sun gear 211, in this embodiment, the rotational speed of the output stage is set to be higher than the rotational speed of the input stage of the planetary gear mechanism 210. It is possible to increase the speed. The encoder 300 is a rotary encoder that includes a rotating disk 310, a light emitting unit 320, and a light receiving unit 370. The configuration of the encoder 300 will be described later.

  FIG. 2 is an explanatory diagram illustrating an example of a control block of the motor system. The control unit 500 of the motor 100 includes a CPU 505, a drive control circuit unit 510, a PWM control unit 520, a drive unit 530, a current detection unit 535, and a measurement unit 540. The measurement unit 540 determines the maximum current value based on the detection current signal Imes output from the current detection unit 535, the magnetic sensor signal Smag output from the magnetic sensor 140, and the synthesized pulse signal Senc output from the encoder 300. This is an arithmetic circuit that calculates Imax, average current value Iave, and motor rotation speed Nmes. The drive control circuit unit 510 and the PWM control unit 520 execute control of the motor 100 (electric servo motor 100) based on the maximum current value Imax and / or the average current value Iave and the motor rotation speed Nmes. Specifically, the drive control circuit unit 510 determines an adjustment value for adjusting the pulse width in the PWM control based on the maximum current value Imax and / or the average current value Iave and the motor rotation speed Nmes, and sets the adjustment value to this adjustment value. Based on this, the PWM control unit 520 generates a PWM control signal. The drive unit 530 includes an H bridge circuit (not shown) configured by a plurality of switching elements. Driving voltage is supplied from the driving unit 530 to the electromagnetic coil of the motor 100 by turning on and off the switching elements of the bridge circuit. The current detection unit 535 is a current sensor that measures a current flowing through the driving unit 530 (that is, a current flowing through the coil 130 of the motor 100).

    FIG. 3 is an explanatory diagram showing the configuration of the encoder. FIG. 3A shows the rotating disk of the encoder 300. The rotating disk 310 includes a plurality of slits 311 to 314. In this embodiment, four rows of slits are provided along the circumference of the rotary disk 310 from the outermost circumference to the slits 311, 312, 313, and 314. There are m slits 311 (m is an integer greater than or equal to 2), and each slit 311 is arranged at equiangular intervals with respect to the center O of the rotating disk. That is, the angle PT formed by the centers P and Q of the two adjacent slits 311P and 311Q and the center O of the rotating disk 310 is 2π / m. This angle PT = 2π / m corresponds to the pitch of the slit, and the configuration of the slit 311 is the same for the other slits 312 to 314. In the present specification, an angle measured on the rotating disk 310 is referred to as a “mechanical angle”.

  The slits 311 to 314 in each row are shifted by an angle Δθm = π / 4m clockwise from the outer side (slit 311 side) to the inner side (slit 314 side) with the center O of the rotating disk 310 as the center. Has been placed. For example, the magnitude of the angle Δθm formed by the centers R and S of the two slits 311R and 312S adjacent in the radial direction and the center O of the rotating disk 310 is π / 4m. Here, the denominator “4” depends on the slits being “4 rows” in the present embodiment. That is, when there are n rows of slits, the shift amount Δθm is π / (m · n) in mechanical angle. In this embodiment, the shift amount between the slits 311 and 312, the shift amount between the slits 312 and 313, and the shift amount between the slits 313 and 314 are π / 4 m, and π / m between adjacent columns. The slits are arranged so as to shift by 4 m. Instead, the shift amount between non-adjacent columns is set to π / 4 m shift so that the shift amount between the slits 311 and 313 is π / 4 m. You may arrange | position a slit like this. That is, an arbitrary one of the four columns is arranged to be shifted by π / 4 m from one or two of the remaining three columns. That is, if the number of columns is n, any one of the n columns is arranged to be shifted by π / (m · n) from one or two of the remaining n−1 columns. Has been.

  FIG. 3B is an explanatory diagram illustrating a circuit configuration of the encoder 300. The encoder 300 includes a light emitting unit 320, a light receiving unit 370, a light emission control unit 325, and a logic operation unit 380. The light emitting unit 320 includes light emitting elements 321 to 324, and the light receiving unit 370 includes light receiving elements 371 to 374. As the light emitting elements 321 to 324, for example, light emitting diodes can be used. As the light receiving elements 371 to 374, for example, a photodiode, a phototransistor, a CCD sensor, or a CMOS sensor can be used. The light emitting elements 321 to 324 and the light receiving elements 371 to 374 are arranged so as to sandwich the rotating disk 310. The light emitting elements 321 to 324 and the light receiving elements 371 to 374 are arranged corresponding to the slits 311 to 314, respectively. The light emitting elements 321 to 324 and the light receiving elements 371 to 374 are arranged in the radial direction of the rotating disk 310. A light emission control unit 325 is connected to the light emitting elements 321 to 324, and a logic operation unit 380 is connected to the light receiving elements 371 to 374. When the light receiving elements 371 to 374 receive light that has passed through the slits 311 to 314, the light receiving elements 371 to 374 generate rectangular wave-shaped light receiving signals S1 to S4, respectively.

  The logic operation unit 380 includes a synthetic pulse signal generation unit 381 and a rotation direction signal generation unit 390. The combined pulse signal generation unit 381 generates a combined pulse signal Senc using the light reception signals S1 to S4 from the light receiving elements 371 to 374. The rotation direction signal generation unit 390 generates rotation direction signals Q1 and Q2 using the light reception signals S1 and S2.

  FIG. 4 is an explanatory diagram illustrating an example of a circuit configuration of the composite pulse signal generation unit. The combined pulse signal generation unit 381 includes amplifiers 382 to 385 and XOR circuits 386 to 388. The amplifiers 382 to 385 amplify the light reception signals S1 to S4, respectively. In the present embodiment, the same signal name as the signal name before amplification is used for the signal name after amplification. The XOR circuit 386 takes an exclusive OR (hereinafter referred to as “XOR”) of the light reception signals S1 and S2 and outputs a signal S1XORS2. The XOR circuit 387 takes the XOR of the received light signals S3 and S4 and outputs a signal S3XORS4. The XOR circuit 388 takes the XOR of the signals S1XORS2 and S3XORS4 and generates a combined pulse signal Senc.

  FIG. 4B is an explanatory diagram showing another configuration of the combined pulse signal generation unit. In this configuration, an OR circuit 389 is provided instead of the final-stage XOR circuit 388. In this way, if possible, a configuration employing an OR circuit instead of an XOR circuit may be used. In general, in the case of a transistor circuit, an OR circuit is more preferable than an XOR circuit because the number of elements can be reduced. Note that various configurations other than these can be adopted as the configuration of the combined pulse signal generation unit.

  FIG. 5 is a timing chart of the composite pulse signal generation unit. The received light signals S1 to S4 are shifted by π / 4 m in mechanical angle. Here, if it is considered that the phase difference Δθe of one period PT of each light reception signal corresponds to 2π, the light reception signals S1 to S4 are shifted by π / 4. One cycle of the pulse of the composite pulse signal Senc is 2π / 4 m in mechanical angle, and is ¼ of the mechanical angle PT (= 2π / m) of the cycle of the light reception signal S1. Accordingly, the number of pulses per unit time of the composite pulse signal Senc is four times the number of pulses per unit time of the light reception signal SA1. In general, if there are n rows of slits, it is possible to make the number of pulses of the synthesized pulse signal Senc n times the number of pulses of each received light signal.

  FIG. 6 is an explanatory diagram illustrating an example of the rotation direction signal generation unit. The rotation direction signal generation unit 390 includes latch circuits 391 and 392. As the latch circuits 391 and 392, for example, a D-flip flop circuit can be used. The latch circuits 391 and 392 include an input terminal D, a clock terminal C, and an output terminal Q. The signal input to the input terminal D is latched at the rising edge of the signal input to the clock terminal C and is output to the output terminal Q. In this embodiment, the light reception signal S1 is input to the input terminal D of the latch circuit 391, the light reception signal S2 is input to the clock terminal C, and the rotation direction signal Q1 is output from the output terminal Q. The light reception signal S2 is input to the input terminal D of the latch circuit 392, the light reception signal S1 is input to the clock terminal C, and the rotation direction signal Q2 is output from the output terminal Q.

  FIG. 7 is a timing chart in the rotation direction signal generation unit. FIG. 7A is a timing chart during normal rotation. In the period from the start to the rise of the light reception signal S2, the rotation direction signal Q1 is indefinite. The latch circuit 391 latches the light reception signal S1 at the rising edge of the light reception signal S2, and outputs the rotation direction signal Q1. In this embodiment, since the light reception signal S1 is H when the light reception signal S2 rises, the rotation direction signal Q1 is H. On the other hand, the rotation direction signal Q2 is indefinite during the period from the start until the light reception signal S1 rises. The latch circuit 392 latches the light reception signal S2 at the rising edge of the light reception signal S1, and outputs a rotation direction signal Q2. In this embodiment, since the light reception signal S2 is L when the light reception signal S1 rises, the rotation direction signal Q2 is L. FIG. 7B is a timing chart during reverse rotation. During reverse rotation, the order of the light reception signals S1 and S2 is reversed from that during forward rotation. As can be seen from the rotation direction signals Q1 and Q2, in the case shown in FIG. 7B, it can be seen that the encoder 300 is rotating in the reverse direction.

  As described above, according to the present embodiment, the number of pulses to be generated is quadrupled by arranging the slits 311 to 314 with a shift of π / 4 m without complicating the shapes of the slits 311 to 314. Is possible. In addition, since the encoder can have a high resolution, it can be used to control an extremely low rotation motor.

[Second Embodiment]
FIG. 8 is an explanatory diagram showing a circuit configuration of the encoder 300 in the second embodiment. The second embodiment is different from the first embodiment in that it includes two light receiving elements 371A, 371B to 374A, 374B corresponding to the light emitting elements 321 to 324, respectively.

  FIG. 9 is an explanatory diagram illustrating an example of the composite pulse signal generation unit in the second embodiment. In the second embodiment, two synthetic pulse signal generators 381A and 381B are provided. The synthesized pulse signal generators 381A and 381B are the same as the synthesized pulse signal generator 381 of the first embodiment except for the input and output signals. That is, in the combined pulse signal generation unit 381A shown in FIG. 9A, the received light signals SA1 to SA4 are input instead of the received light signals S1 to S4, and the combined pulse signal SencA is output. Here, the light receiving signals SA1 to SA4 are signals generated from the light receiving elements 371A to 374A, respectively. In the combined pulse signal generation unit 381B shown in FIG. 9B, the received light signals SB1 to SB4 are input instead of the received light signals S1 to S4, and the combined pulse signal SencB is output.

  FIG. 10 is an explanatory diagram illustrating an example of the rotation direction signal generator in the second embodiment. The rotation direction signal generation unit 390 of the second embodiment is the same as the rotation direction signal generation unit 390 of the first embodiment except that the input signal and the output signal are different. That is, as shown in FIG. 10A, the rotation direction signal generation unit 390 receives the combined pulse signals SencA and SencB instead of the light reception signals S1 and S2. As shown in FIG. 10B, received light signals SA1 and SB1 may be input instead of the combined pulse signals SencA and SencB.

  FIG. 11 is a timing chart of the logic operation unit in the second embodiment. It is almost the same as the timing chart shown in FIG. In the timing chart shown in FIG. 11, the signals SB1 to SencB are shifted rightward by an amount corresponding to the phase difference between the light receiving elements 371A to 374A and 371B to 374B shown in FIG. It should be noted that the rotation direction signals Q1 and Q2 can be easily exchanged by simply reversing the arrangement positions of the light receiving elements 371A to 374A and 371B to 374B.

[Third embodiment]
FIG. 12 is an explanatory diagram illustrating a circuit configuration of the encoder 300 according to the third embodiment. In the third embodiment, the number of rows of slits in the first embodiment is three, and the number of light emitting elements and light receiving elements corresponding thereto is also three. In this case, the magnitude of the angle Δθm formed by the centers R and S of the two slits 311R and 312S and the center O of the rotating disk 310 is π / 3m.

  FIG. 13 is an explanatory diagram illustrating a composite pulse signal generation unit according to the third embodiment. The combined pulse signal generation unit 381 includes amplifiers 382 to 384 and XOR circuits 386 and 388. The amplifiers 382 to 384 amplify the light reception signals S1 to S3, respectively. The XOR circuit 386 takes the XOR of the received light signals S1 and S2 and outputs a signal AEX. The XOR circuit 388 takes the XOR of the signals AEX and S3 and outputs a combined pulse signal Senc. The configuration of the rotation direction signal generation unit 390 is the same as the configuration of the rotation direction signal generation unit 390 of the first embodiment.

  FIG. 14 is a timing chart of the logic operation unit of the logic operation unit of the encoder according to the third embodiment. As described above, according to the present embodiment, the number of pulses to be generated is tripled by arranging the slits 311 to 313 with a mechanical angle shifted by π / 3 m without complicating the shape of the slits 311 to 313. It is possible.

[Fourth embodiment]
FIG. 15 is an explanatory diagram illustrating a circuit configuration of the encoder 300 according to the fourth embodiment. In the first embodiment, the slits 311 to 314 in each row have an angle Δθm = clockwise in order from the outside (slit 311 side) to the inside (slit 314 side) with the center O of the rotating disk 310 as the center. They are shifted by π / 4m. In contrast, in the fourth embodiment, the slits 311 to 314 in each row are arranged so as not to shift. That is, the magnitude of the angle Δθm formed by the centers R and S of the two slits 311R and 312S adjacent in the radial direction and the center O of the rotating disk 310 is zero. In the first embodiment, the light emitting elements 321 to 324 and the light receiving elements 371 to 374 are arranged in the radial direction of the rotating disk 310. In the fourth embodiment, the center O of the rotating disk 310 is the center. Further, they are arranged in such a manner that they are sequentially shifted in the counterclockwise direction by an angle Δθm = π / 4m from the outside (light receiving element 321) to the inside (light receiving element 324). As described above, the slits 311 to 314, the light emitting elements 321 to 324, and the light receiving elements 371 to 374 may be arranged. The relative positions of the slits 311 to 314, the light emitting elements 321 to 324, and the light receiving elements 371 to 374 in the fourth embodiment are the same as the slits 311 to 314, the light emitting elements 321 to 324, and the light receiving elements in the first embodiment. It is possible to keep the position relative to the elements 371 to 374 unchanged.

  From the above, it is possible to increase the number of pulses to be generated by n times by arranging n slits and shifting each column by π / (m · n). That is, the encoder 300 can have a high resolution with a simple configuration. In addition, n may be 2 or more, but 3 or more is preferable. If it is 3 or more, it is possible to easily determine the rotation direction of the rotating disk without arranging two light receiving elements in one row.

[Modification]
In this embodiment, slits 311 to 314 as optical elements are formed in the rotating disk 310, but instead of the slits 311 to 314, a reflector may be arranged as an optical element. In this case, the light emitting unit 320 and the light receiving unit 370 are arranged on the same side with respect to the rotating disk 310.

  In this embodiment, the speed increaser 200 is provided, but the speed increaser 200 can be omitted. That is, the drive shaft 110 of the motor 100 and the rotary disk 310 of the encoder 300 may be directly coupled. If the speed increaser 200 is provided, the number of pulses to be generated can be further increased, so that the motor 100 can be rotated at a lower speed. A transmission may be used instead of the speed increaser 200.

  The present invention is applicable to motors of various devices such as a fan motor, a timepiece (hand drive), a drum type washing machine (single rotation), a roller coaster, and a vibration motor. When the present invention is applied to a fan motor, extremely low rotation driving is possible, and various effects (low power consumption, low vibration, low noise, low rotation unevenness, low heat generation, long life) are particularly remarkable. is there. Such fan motors are, for example, various devices such as digital display devices, in-vehicle devices, fuel cell computers, fuel cell digital cameras, fuel cell video cameras, fuel cell mobile phones and other fuel cell equipment, projectors, etc. Can be used as a fan motor for equipment. The motor of the present invention can also be used as a motor for various home appliances and electronic devices. For example, the motor according to the present invention can be used as a spindle motor in an optical storage device, a magnetic storage device, a polygon mirror driving device, or the like. The motor according to the present invention can also be used as a motor for a moving body or a robot.

  FIG. 16 is an explanatory diagram showing a projector using a motor according to an application example of the invention. The projector 1600 includes three light sources 1610R, 1610G, and 1610B that emit red, green, and blue color lights, and three liquid crystal light valves 1640R, 1640G, and 1640B that modulate the three color lights, respectively. A cross dichroic prism 1650 that synthesizes the modulated three-color light, a projection lens system 1660 that projects the synthesized three-color light onto the screen SC, a cooling fan 1670 for cooling the inside of the projector, and a projector 1600 And a control unit 1680 for controlling the whole. As the motor for driving the cooling fan 1670, the above-described various brushless motors can be used.

  FIG. 17 is an explanatory view showing a fuel cell type mobile phone using a motor according to an application example of the present invention. FIG. 17A illustrates an appearance of the mobile phone 1700, and FIG. 17B illustrates an example of an internal configuration. The mobile phone 1700 includes an MPU 1710 that controls the operation of the mobile phone 1700, a fan 1720, and a fuel cell 1730. The fuel cell 1730 supplies power to the MPU 1710 and the fan 1720. One fan 720 is used to blow air from outside the mobile phone 1700 to supply air to the fuel cell 1730 or to discharge moisture generated by the fuel cell 1730 from the inside of the mobile phone 1700 to the outside. Is. Note that one fan 720 may be disposed on the MPU 1710 as shown in FIG. 17C to cool the MPU 1710. As the motor for driving the fan 1720, the various brushless motors described above can be used.

  FIG. 18 is an explanatory diagram showing an electric bicycle (electric assisted bicycle) as an example of a moving body using a motor / generator according to an application example of the present invention. This bicycle 1800 is provided with a motor 1810 on the front wheel, and a control circuit 1820 and a rechargeable battery 1830 on a frame below the saddle. The motor 1810 assists running by driving the front wheels using the electric power from the rechargeable battery 1830. In addition, the electric power regenerated by the motor 1810 is charged in the rechargeable battery 1830 during braking. The control circuit 1820 is a circuit that controls driving and regeneration of the motor. As the motor 1810, the above-described various brushless motors can be used.

  FIG. 19 is an explanatory diagram showing an example of a robot using a motor according to an application example of the present invention. The robot 1900 has first and second arms 1910 and 1920 and a motor 1930. The motor 1930 is used when the second arm 1920 as a driven member is rotated horizontally. As the motor 1930, the various brushless motors described above can be used.

  The embodiments of the present invention have been described above based on some examples. However, the above-described embodiments of the present invention are for facilitating the understanding of the present invention and limit the present invention. It is not a thing. The present invention can be changed and improved without departing from the spirit and scope of the claims, and it is needless to say that the present invention includes equivalents thereof.

100 ... Motor (electric servo motor)
DESCRIPTION OF SYMBOLS 110 ... Drive shaft 120 ... Magnet 130 ... Electromagnetic coil (coil)
140 ... magnetic sensor 200 ... speed increaser 210 ... planet gear mechanism 211 ... sun gear (sun gear)
212 ... Planetary gear (planetary gear)
215 ... Outer gear (outer ring gear)
DESCRIPTION OF SYMBOLS 300 ... Encoder 310 ... Rotary disk 311-314 ... Slit 320 ... Light emission part 321-324 ... Light emission element 325 ... Light emission control part 370 ... Light reception part 371-374, 371A-374A, 371B-374B ... Light reception element 380 ... Logic operation part 381 ... Synthetic pulse signal generation unit 382-385 ... Amplifier 386-388 ... XOR circuit 389 ... OR circuit 390 ... Rotation direction signal generation unit 391, 392 ... Latch circuit 400 ... Load 410 ... Synthetic pulse signal generation unit 500 ... Control unit 510 ... Drive control circuit unit 530 ... Drive unit 535 ... Current detection unit 540 ... Measurement unit 1600 ... Projector 1610R ... Light source 1640R ... Liquid crystal light valve 1650 ... Cross dichroic prism 1660 ... Projection lens system 1670 ... Cooling fan 1680 ... Control unit 1 00 ... mobile phone 1720 ... fan 1730 ... fuel cell 1800 ... bicycle 1810 ... motor 1820 ... control circuit 1830 ... rechargeable battery 1900 ... robot 1910 ... second arm 1920 ... second arm 1930 ... motor S ... number of teeth G ... teeth Number Imes ... Detection current signal Smag ... Magnetic sensor signal Senc, SencA, SencB ... Synthetic pulse signal Imax ... Maximum current value Iave ... Average current value Nmes ... Motor speed O-S ... Center S1XORS2 ... Signal S3XORS4 ... Signal D ... Input terminal C ... Clock terminal Q ... Output terminal S1 to S4, SA1 to SA4, SB1 to SB4 ... Light receiving signal Q1, Q2 ... Rotation direction signal SC ... Screen AEX ... Signal

Claims (4)

An encoder,
A rotating disk,
An optical element array composed of slits or reflectors provided at equal intervals on the rotating disk,
A light emitting unit for irradiating the optical element row with light;
A light receiving unit that receives light that passes through or reflects the individual optical elements of the optical element row and outputs a rectangular light reception signal; and
With
The optical element row is:
N rows are arranged along the circumference of n pieces (n is an integer of 2 or more) with different distances from the center of the rotating disk,
The n sets of optical element arrays each include an equal number of m (m is an integer of 2 or more) optical elements,
The light emitting unit and the light receiving unit are arranged in n sets corresponding to the n sets of optical element rows,
When the phase difference of one period of each light receiving signal is defined as 2π, the n sets of optical element arrays and the n sets of light emitting units and light receiving units are n pieces of light generated by the n sets of light receiving units. It is arranged so that the phase of the received light signal is sequentially shifted by π / n.
encoder. The encoder according to claim 1,
An encoder in which the n sets of optical element arrays are sequentially shifted by π / (m · n) in mechanical angle measured on the rotating disk. The encoder according to claim 1 or 2,
n is 3 or more encoder. An electromechanical device,
A magnet,
An electromagnetic coil;
The encoder according to any one of claims 1 to 3,
A control unit for controlling electric power supplied to the electromagnetic coil using an output of the encoder;
An electromechanical device comprising:

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