JP7239891B2 - Encoder device and its control method, drive device, stage device, and robot device - Google Patents

Description

The present invention relates to an encoder device, a method of using the encoder device, a driving device, a stage device, and a robot device.

2. Description of the Related Art An encoder device that detects position information such as a rotation angle or rotation speed of an object to be inspected is mounted on various devices such as a robot device. As a conventional encoder device, there is known a device that illuminates a pattern with a light-emitting element, receives light from the pattern with a light-receiving element, and causes the light-emitting element to emit light intermittently. 1).
Encoder devices such as those described above are desired to reduce power consumption and improve the reliability of detection results.

JP-A-10-267693

According to the first aspect, the first detection section irradiates the moving section with light, detects the light from the moving section and outputs a first detection signal, and the first detection section irradiates the moving section with light and moves the light. a second detection unit that detects light from the unit and outputs a second detection signal; and a calculation unit that obtains movement information of the moving unit from at least one of the first detection signal and the second detection signal. The encoder device includes a control section that intermittently drives the first detection section and the second detection section and makes the drive cycle of the second detection section longer than the drive cycle of the first detection section. An encoder device is provided.

According to the second aspect, the first detection section irradiates the moving section with light, detects the light from the moving section and outputs a first detection signal, and the first detection section irradiates the moving section with light and moves the light. An encoder device comprising: a second detector that detects light from a part and outputs a second detection signal; and a calculator that obtains movement information of the moving part from the first detection signal, An encoder device is provided that includes a control unit that determines the movement information using the second detection signal according to the state of the detection signal and the second detection signal.
According to the third aspect, detection is performed by irradiating the moving part with light, detecting the light from the moving part, and outputting a first detection signal and a second detection signal having phases different from each other with respect to the movement of the moving part. and a controller that detects an abnormality of the detector based on a change in the combination of the first detection signal and the second detection signal due to the movement of the moving part.

According to a fourth aspect, there is provided a driving device including the encoder device according to the first to third aspects and a power supply section that supplies power to the moving section.
According to a fifth aspect, there is provided a stage apparatus comprising a moving object and the driving device of the third aspect for moving the moving object.
According to a sixth aspect, there is provided a robot apparatus comprising the driving device according to the fourth aspect and an arm relatively moved by the driving device.
According to the seventh aspect, the first detection section irradiates the moving section with light, detects the light from the moving section and outputs the first detection signal, and the first detection section irradiates the moving section with light and moves the light. a second detection unit that detects light from the unit and outputs a second detection signal; and a calculation unit that obtains movement information of the moving unit from at least one of the first detection signal and the second detection signal. A method of controlling an encoder device, intermittently driving the first detection section and the second detection section, and making the drive cycle of the second detection section longer than the drive cycle of the first detection section. There is provided a method of using an encoder device comprising:

It is a figure which shows the encoder apparatus which concerns on 1st Embodiment. 2A is a plan view showing the disc and the detection section in FIG. 1, and FIG. 3B is a diagram showing the detection section, the detection circuit section, etc. in FIG. 1. FIG. (A) is a diagram showing an example of four detection signals in FIG. 2 (B), (B) is a diagram showing an example of light emission timing of two light emitting elements in FIG. FIG. 3B is a diagram showing state transitions of detection signals of the two detection units, and FIG. 3D is a diagram showing another example of light emission timings of the two light emitting elements of FIG. 4 is a flow chart showing an example of how to use the encoder device of the first embodiment; 5 is a diagram showing an example of state changes of a detection signal in the usage of FIG. 4; FIG. (A) is a plan view showing a disk and a detection section of a modification, (B) is a diagram showing an example of four detection signals obtained from the detection section of FIG. 6(A), and (C) is FIG. 6(A). 2 is a diagram showing an example of light emission timing of light emitting elements of the detection unit of FIG. It is a flowchart which shows an example of the usage method of 2nd Embodiment. (A) is a diagram showing an example of changes in four detection signals, and (B) is a diagram showing an example of light emission timings of two light emitting elements. 9A is a plan view showing the disc and detection section of the third embodiment, and FIG. 9B is a diagram showing the detection section and the like of FIG. 9A; FIG. (A) is a diagram showing an example of four detection signals obtained from the detection unit in FIG. 9B, (B) is a diagram showing an example of the detection signal of the light emitting element in FIG. FIG. 10 is a diagram showing an example of light emission timing of the light emitting element of the detection unit in FIG. 9B; It is a figure which shows an example of a drive device. It is a figure which shows an example of a stage apparatus. It is a figure which shows an example of a robot apparatus.

[First embodiment]
A first embodiment will be described with reference to FIGS. 1 to 5. FIG. FIG. 1 shows an encoder device EC according to this embodiment. In FIG. 1, an encoder device EC detects rotational position information of a rotary shaft SF (moving portion) of a motor M (power supply portion). The rotating shaft SF is, for example, the shaft (rotor) of the motor M, and is an action shaft (output shaft) connected to the shaft of the motor M via a power transmission unit such as a transmission and to a load. may Rotational position information detected by the encoder device EC is supplied to the motor control unit 26 . The control unit 27 of the motor control unit 26 controls rotation of the motor M (for example, rotation position, rotation speed, etc.) using the rotation position information supplied from the encoder device EC. The motor control unit 26 controls rotation of the rotation shaft SF.

The encoder device EC includes a position detection system (position detection unit) 2 that detects rotational position information of the rotary shaft SF. The encoder device EC is a so-called multi-rotation absolute encoder. The position detection system 2 includes a multi-rotation information detection unit 3 that detects multi-rotation information indicating the number of rotations of the rotation shaft SF, and rotational position information including angular position information indicating an angular position (rotation angle) of less than one rotation. An angle detection unit 4 for detecting is provided.

At least part of the position detection system 2 (for example, the angle detection unit 4) is powered by, for example, a power supply (hereinafter referred to as a main power supply) for a device (for example, a drive device, a stage device, a robot device) on which the encoder device EC is mounted. While power is being supplied, it operates by receiving power from its main power supply (first power supply). At least part of the position detection system 2 (for example, the multi-rotation information detection unit 3) is, for example, in a state in which the main power supply supplies power (power-on state), and in a state in which the main power supply supplies power. It operates by receiving power supply from the battery 15 (first power supply) when it is not in a state (power-off state, backup state, etc.).

The battery 15 has, for example, a primary battery (button battery or the like) and a rechargeable secondary battery. A switching unit 16 is connected to the battery 15 . The power supply MCE of the motor controller 26 is part of its main power supply. While the power supply unit MCE is supplying power (power-on state), the power supply unit MCE charges the secondary battery of the battery 15 . The switching unit 16 then supplies power from the secondary battery to the multi-rotation information detection unit 3 . On the other hand, when the power supply unit MCE does not supply power (power-off state), the secondary battery is not charged. In this state, when the secondary battery has much remaining power, the switching unit 16 may supply power from the secondary battery to the multi-rotation information detection unit 3 . Further, when the power is off and the remaining power of the secondary battery is low, the switching unit 16 may supply the power from the primary battery to the multi-rotation information detection unit 3 . Therefore, even when the power is off, the position detection system 2 (multi-rotation information detection unit 3) can detect at least part of the rotational position information (here, multi-rotation information) of the rotating shaft SF.

The multi-rotation information detection unit 3 optically detects the multi-rotation information, for example. The multi-rotation information detection unit 3 includes a first detection unit 10A for detecting a pattern 8S for detecting multi-rotation information formed on a disc-shaped disk 6 connected to the rotation shaft SF, and detects the pattern 8S at different positions. It has a second detection section 10B and a detection signal processing section 12 . The detection signal processing unit 12 has a detection circuit unit 13, a storage unit 14 made of, for example, a non-volatile memory, and the battery 15 and switching unit 16 described above. The disk 6 is fixed by bolts 17 (see FIG. 2A) to the disk 5 attached to the rotating shaft SF. Since the disc 5 rotates together with the rotation shaft SF, the disc 6 rotates in conjunction with the rotation shaft SF. In the detection signal processing unit 12, the detection circuit unit 13 processes the detection signals of the detection units 10A and 10B to detect rotational position information (movement information such as multi-rotation information) of the rotation shaft SF. The storage unit 14 stores the rotational position information detected by the detection circuit unit 13 .

The angle detection unit 4 is an optical encoder, for example, and detects positional information (angular positional information) within one rotation of the disc 6 . For example, when an optical encoder is used, the angle detection unit 4 includes a first detection unit 11A that detects light from the pattern 9S for angular position detection of the disk 6, and a second detection unit 11A that detects light from the pattern 9S at different positions. The unit 11B has a detection circuit unit 21 that processes detection signals from the detection units 11A and 11B and detects an angular position within one rotation of the rotation shaft SF. Pattern 9S includes, for example, an absolute scale and an incremental scale. As for the angle detection section 4, the second detection section 11B may be omitted.

The detection circuit unit 21 detects the angular position of the first resolution using, for example, the result of detecting light from the absolute scale. Further, the detection circuit unit 21 detects an angular position with a second resolution higher than the first resolution by performing an interpolation operation on the angular position with the first resolution using the result of detecting light from the incremental scale. do. Also, the disc 6 may be a member integrated with the disk 5, for example. Further, the multi-rotation information detection unit 3 and the angle detection unit 4 are, for example, reflection type optical encoders, but they may be configured by transmission type optical encoders.

In this embodiment, the encoder device EC includes a signal synthesizing section 22 . The signal synthesizing unit 22 calculates and processes the detection result by the position detection system 2 . The signal synthesizing unit 22 includes a synthesizing unit 23 and a data communication unit 24 . The synthesis unit 23 acquires the angular position information of the second resolution detected by the detection circuit unit 21 . Also, the synthesizing unit 23 acquires the multi-rotation information of the rotating shaft SF from the storage unit 14 of the multi-rotation information detecting unit 3 . The synthesizing unit 23 receives angular position information from the detection circuit unit 21,
And the multi-rotation information from the multi-rotation information detection unit 3 is combined to calculate the rotational position information. For example, when the detection result of the detection circuit unit 21 is θ (rad) and the detection result of the multi-rotation information detection unit 3 is n rotations, the synthesizing unit 23 outputs (2π×n+θ) (rad ) is calculated. The rotational position information may be a combination of multi-rotation information and angular position information for less than one rotation.

The synthesizer 23 supplies the rotational position information to the data communication unit 24 . The data communication unit 24 is communicably connected to the communication unit MCC of the motor control unit 26 by wire or wirelessly. The data communication unit 24 supplies the rotational position information in digital format to the communication unit MCC of the motor control unit 26 . The control unit 27 of the motor control unit 26 acquires rotational position information from the data communication unit 24, for example, at a predetermined sampling rate. The control unit 27 controls the rotation of the motor M by controlling the power (driving power) supplied to the motor M using the rotational position information.

Next, the multi-rotation information detector 3 of this embodiment will be described.
2A is a plan view showing the disk 6 and detection units 10A and 10B in FIG. 1, and FIG. etc. is a figure. As shown in FIG. 2(A), on the surface of the disk 6, there are provided a reflective first pattern 8A and a second pattern 8B each having a shape of 1/2 of four concentric annular zones around the center of rotation. , a third pattern 8C, and a fourth pattern 8D are formed. That is, each of the patterns 8A to 8D is a semi-annular pattern with an opening angle of 180°. is set to be progressively smaller. The second pattern 8B is arranged by rotating the first pattern 8A by 180° around its rotation center, and the third pattern 8C and the fourth pattern 8D are arranged around its rotation center respectively. This arrangement is obtained by rotating the pattern 8B clockwise by 90°. Patterns 8A to 8D correspond to pattern 8S in FIG. A pattern 9S for the angle detection section 4 in FIG. 1 is formed outside the patterns 8A to 8D.

Further, the first detection section 10A is arranged to face the patterns 8A to 8D, and the second detection section 10B is arranged at a position rotated clockwise by 90° around the rotation center of the first detection section 10A. It is
As shown in FIG. 2B, the first detection unit 10A includes light emitting diodes (hereinafter referred to as LEDs) 31 that irradiate the patterns 8A to 8D with light for detection, and light from the patterns 8A, 8B, 8C, and 8D. It has light receiving elements 32A, 32B, 32C and 32D for receiving reflected light. Further, the first detection unit 10A includes an analog comparator 33A that obtains a detection signal MA1 obtained by digitizing the difference between the signals output from the light receiving elements 32A and 32B, and digitizes the difference between the signals output from the light receiving elements 32C and 32D. and an analog comparator 33B for obtaining the detected signal MB1. The detection signals MA1 and MB1 are supplied to the counter 40 of the detection circuit section 13. FIG. As shown in FIG. 3A, the detection signals MA1 and MB1 are rectangular wave signals whose period is a period of one rotation of the disk 6 (the rotation angle is 360°). The phase of MB1 is shifted by 90°. Note that the horizontal axis of FIGS. 3A and 3B is time t.

Similarly, the second detection unit 10B includes light emitting diodes (hereinafter referred to as LEDs) 34 that irradiate the patterns 8A to 8D with light for detection, and light receiving elements that receive reflected light from the patterns 8A, 8B, 8C, and 8D. 35A, 35B, 35C and 35D. Any light-emitting device such as a semiconductor laser can be used instead of the LEDs 31 and 34 . Photodiodes, for example, can be used as the light receiving elements 32A to 32D and 35A to 35D.

Further, the second detection section 10B has an analog comparator 36A that obtains a detection signal MA2 obtained by digitizing the difference between the signals output from the light receiving elements 35A and 35B, and digitizes the difference between the signals output from the light receiving elements 35C and 35D. and an analog comparator 36B for obtaining the detected signal MB2. The detection signals MA2 and MB2 are also supplied to the counter 40 of the detection circuitry 13. FIG. The detection signals MA2 and MB2 are, as shown in FIG. 3A, rectangular wave signals whose one cycle is the period of one rotation of the disk 6, and the phase of the detection signal MB2 is shifted by 90° with respect to the detection signal MA2. are doing. Furthermore, in this embodiment, the position of the second detection section 10B is different from the position of the first detection section 10A by 90°. Therefore, as shown in FIG. 3A, the phases of the detection signals MA2 and MB2 are shifted by 90° (1/4 of one cycle) with respect to the detection signals MA1 and MB1. As an example, the phase of the detection signal MA2 is substantially equal to the phase of the detection signal MB1, and the phase of the detection signal MB2 is different from the phase of the detection signal MA1 by substantially 180°. As an example, the changes in the detection signals MA1 to MB2 in FIG. 3A are obtained when the disc 6 in FIG. 2A is rotated counterclockwise (hereinafter referred to as forward direction).

In FIG. 2B, the detection circuit section 13 includes a counter 40, an oscillation circuit 38 that outputs a pulse signal PS of a predetermined cycle, and an intermittent light emission of the LEDs 31 and 34 using the pulse signal PS. and a light emission control unit 39 . As an example, the light emission control unit 39 causes the LED 31 to emit light with a drive signal 31L having a period TA that is a predetermined integral multiple of the period of the pulse signal PS, and causes the LED 34 to emit light with a drive signal 34L having a period TB that is longer than the period TA. As shown in FIG. 3B, as an example, the cycle TB of the drive signal 34L is twice the cycle TA of the drive signal 31L. By causing the LEDs 31 and 34 to emit light intermittently in this manner, power consumption in the first detection units 10A and 10B can be suppressed.

Further, the light emission control unit 39 counts the sampling signal SSA for the first detection unit 10A that changes at the same timing as the drive signal 31L and the sampling signal SSB for the second detection unit 10B that changes at the same timing as the drive signal 34L. 40. The counter 40 reads the detection signals MA1 and MB1 in synchronization with the sampling signal SSA, and reads the detection signals MA2 and MB2 in synchronization with the sampling signal SSB. In FIG. 3A and the like, the detection signals MA1 to MB2 are represented as continuous rectangular wave signals for convenience of explanation. This is an intermittent signal extracted from the 34L portion. Further, in this specification, intermittent light emission of the LEDs 31 and 34 and reading of the detection signals MA1 to MB2 in synchronization with the sampling signals SSA and SSB intermittently drives the detection units 10A and 10B as an example. means that In addition, the light emission control unit 39 continuously lights the LEDs 31 and 34 and supplies the sampling signals SSA and SSB that change periodically to the counter 40, so that the detection period of the detection signals MA1 to MB2 in the counter 40 ( signal detection cycle).

When the first detection unit 10A is operating normally, the counter 40 uses the detection signals MA1 and MB1 read from the first detection unit 10A to obtain multi-rotation information (such as the number of rotations) of the rotation shaft SF. can ask. For example, if the detection signal MB1 is low level when the detection signal MA1 transitions from low level to high level (in the case of forward rotation), the counter 40 outputs an up signal to the storage section 14 . On the other hand, if the detection signal MB1 is high level when the detection signal MA1 transitions from low level to high level (reverse rotation), the counter 40 outputs a down signal to the storage section 14 . In the storage unit 14, the number of rotations (multi-rotation information) of the rotating shaft SF is obtained by increasing or decreasing the number of rotations stored so far according to the up signal or the down signal. Furthermore, when the second detection unit 10B is operating normally, the counter 40 can obtain the multi-rotation information of the rotation shaft SF using the detection signals MA2 and MB2 read from the second detection unit 10B. can. In the present embodiment, for example, when the first detection unit 10A does not operate normally, the multi-rotation information of the rotating shaft SF is obtained by using the detection signals MA2 and MB2 of the second detection unit 10B. Information can be obtained with high accuracy.

Next, an example of how to use the encoder device EC of this embodiment will be described with reference to the flowchart of FIG. As an example of its usage, the counter 40 determines whether the detectors 10A and 10B are operating normally. In doing so, the counter 40 checks, for example, the state transitions of the detection signals MA1, MB1 and MA2, MB2. As shown in FIG. 3A, the combination of the detection signals MA1 and MB1 includes a state 1 (ST1) in which MA1 is at a high level (hereinafter represented by H) and MB1 is at a low level (hereinafter represented by L). , MA1 and MB1 are (H, H) state 2 (ST2), MA1 and MB1 are (L, H) state 3 (ST3), and MA1 and MB1 are (L, L) state 4 (ST2). ST4). Similarly, the combination of detection signals MA2 and MB2 includes state 1 (ST1) in which MA2 and MB2 are (L, L), state 2 (ST2) in which MA2 and MB2 are (H, L), and MA2 and MB2. There are state 3 (ST3) in which is (H, H) and state 4 (ST4) in which MA2 and MB2 are (L, H). Assuming that the period of the detection signals MA1 and MB1 is T1, the period T2 of each state is T1/4. A period T2 is a period corresponding to a phase difference of 90° between the detection signals MA1 and MB1. In principle, if the detection signals MA1 and MB1 are in states 1-4, the detection signals MA2 and MB2 are also in states 1-4. Incidentally, instead of the counter 40, the light emission control section 39 may determine whether the detection sections 10A and 10B are operating normally. Alternatively, the counter 40 and the light emission control section 39 may work together to determine whether the detection sections 10A and 10B are operating normally.

When the disk 6 in FIG. 2A rotates in the forward direction, as shown in FIG. , state 1, state 2, state 3, state 4, state 1. If the disk 6 rotates in the opposite direction (clockwise), the state transitions 18A and 18B are in the order state 1, state 4, state 3, state 2, state 1. FIG. Patterns of state transitions 18A and 18B when the detection signals MA1 to MB2 are normal are stored in a memory such as a ROM in the counter 40. FIG. However, if the detection signals MA1 and MB1 are near the boundary between states 1 and 2, for example, even if the detection signals MA1 and MB1 transition to state 2, the detection signals MA2 and MB2 are still in state 1. Thus, the states of the detection signals MA1, MB1 and the detection signals MA2, MB2 may differ. As an example, the counter 40 compares the state transitions of the detection signals MA1, MB1 and MA2, MB2 with the pattern shown in FIG.

At step 102 in FIG. 4, the light emission control unit 39 sets the lighting cycle of the LED 31 of the first detection unit 10A to the first cycle TA at time t1 shown in FIG. 3(B). It is assumed that the period T1 of the detection signals MA1 and MB1 is the period when the rotary shaft SF is rotating at the predicted maximum rotational speed. At this time, the first period TA of the LED 31 is within each state of the period T2 of the detection signals MA1 and MB1 (in other words, the period corresponding to the phase difference of 90° between the detection signals MA1 and MB1) as shown in the following equation. is set so that the LED 31 emits light at least twice. As a result, even if the period T2 of each state of the detection signals MA1 and MB1 slightly fluctuates, the counter 40 can accurately detect the state transition 18A of the detection signals MA1 and MB1.

TA<T2/2=T1/8 (1)
Then, in step 104, the light emission control section 39 intermittently lights the LED 34 of the second detection section 10B at the second period TB shown in FIG. 3(B). The period TB is greater than 1 time the period TA and less than or equal to 2 times the period TA, as follows. As an example, the period TB may be set to twice the period TA.

TA<TB≦2TA (2)
This means that the LED 34 of the second detection section 10B emits light at least once within each state of the cycle T2 of the detection signals MA2 and MB2. This allows the counter 40 to accurately detect the state transition 18B of the detection signals MA2 and MB2. If the detection signals MA1 to MB2 are normal, the drive signals 31L and 34L are output at regular intervals as shown in FIG. 3(B).
Also, at step 106, the counter 40 reads the detection signals MA1 and MB1 in synchronization with the sampling signal SSA, and reads the detection signals MA2 and MB2 in synchronization with the sampling signal SSB. The counter 40 stores the state numbers (1 to 4) of the read detection signals MA1, MB1 and MA2, MB2. Here, as shown in FIG. 5A, it is assumed that the states of the detection signals MA1 and MB1 are 1, and the states of the detection signals MA2 and MB2 are also 1. FIGS. 5A to 5E show an example in which the first detection section 10A has an abnormality and the detection signal MB1 is always at low level (L). 5A to 5E, the levels of the detection signal MB1 are different in the states corresponding to the states 2 and 3 in FIG. 3C of the detection signals MA1 and MA2. Therefore, in FIGS. 5A to 5E, the states of the detection signals MA1 and MA2 corresponding to the states 2 and 3 in FIG. 3C are indicated as states 2A and 3A, respectively.

Further, at step 108, counter 40 reads detection signals MA1, MB1 and MA2, MB2 to determine the number of states of the two sets of detection signals. Then, in step 110, the counter 40 obtains multiple rotation information (rotation information) of the rotation shaft SF using the read detection signals MA1 and MB1 of the first detection unit 10A for a plurality of times, and stores the multi-rotation information (rotation information) in the storage unit 14. . Note that the detection signals MA2 and MB2 may be used when obtaining the multi-rotation information. Also, at step 112, the counter 40 compares the states of the detection signals MA1 and MB1 determined at step 108 with the states of the detection signals MA2 and MB2. In the next step 114, if the two state numbers match, it is determined that the detection signals MA1, MB1 and the detection signals MA2, MB2 are normal, the operation returns to step 108, and rotation information Continue detection.

On the other hand, if the states of the two detection signals are different in step 114 as shown in FIG. transition to In this case, as shown in FIG. 5B, even if the detection signals MA2 and MB2 transition to state 2 (H, L), the level (H, L) of state 2A of the detection signals MA1 and MB1 remains state 1. is the same as the level of That is, since the detection signals MA1 and MB1 can be considered to be in state 1, there is a mismatch between the state transitions 18A and 18B. In response to this, in step 116, the counter 40 outputs the alarm signal AS0 supplied to the light emission control section 39 to indicate that at least one of the first detection section 10A and the second detection section 10B is abnormal. Set to high level. Then, as shown in FIG. 3D, the light emission control section 39 sets the lighting cycle of the LED 34 of the second detection section 10B to the first cycle TA (same lighting cycle as the LED 31) at time t2. This is for the case where rotation information is detected in advance using the detection signals MA2 and MB2 because there is a possibility that the first detection section 10A has an abnormality. Then, in step 118, counter 40 reads detection signals MA1, MB1 and MA2, MB2 to determine the number of states of the two sets of detection signals.

In the next step 120, the counter 40 compares the state transitions of the detection signals of the detection units 10A and 10B in the same manner as in step 112, and determines whether the state transition 18A of the first detection unit 10A is as expected. do. When the state transition 18B shifts from FIG. 5A (state 1) to FIG. 5C (state 2) and then shifts to FIG. 5D (state 1), the second detection unit 10B only fluctuated near the boundary between states 1 and 2, and the state of the first detection unit 10A was stopped at state 1. That is, the state transition of the detection signals MA1 and MB1 18A can be determined as expected. At this time, the operation proceeds to step 122, and the counter 40 determines whether or not the state transition 18B of the second detection section 10B is as expected. Since state transition 18B is now as expected, operation proceeds to step 124 and counter 40 returns alarm signal AS0 to a low level. Then, the light emission control unit 39 returns the lighting cycle of the LED 34 of the second detection unit 10B to the second cycle TB at time t3 in FIG. 3(D). Thereafter, in step 126, detection of rotation information using the detection signal of, for example, the first detection section 10A out of the detection sections 10A and 10B is continued.

On the other hand, if the state transition 18B of the second detection unit 10B is not as predicted in step 122, for example, if the state transition 18B moves from state 1 to state 3 without going through states 2 and 4, the operation goes to step 128. In this case, it is determined that the second detection section 10B has an abnormality, so the counter 40 sets the alarm signal AS2 for the second detection section 10B supplied to the light emission control section 39 to high level. In response to this, the light emission control section 39 turns off the LED 34 of the second detection section 10B. Then, in step 130, detection of rotation information using the detection signal of the first detection section 10A is continued. Since the LED 34 is turned off at this time, power consumption can be suppressed.
In step 128, the counter 40 sets the alarm signal AS2 to a high level, and tells the controller 27 of the motor controller 26 in FIG. Alarm information (not shown) of the second detector 10B indicating that detection is possible may be supplied. In response to this, as an example, an administrator (not shown) can replace the second detector 10B at the next maintenance opportunity.

If the state transition 18A of the first detector 10A is not as expected in step 120, the operation proceeds to step 132. FIG. When the state transitions 18A and 18B shift from FIG. 5C to FIG. However, the detection signals MA1 and MB1 of the first detection section 10A (L, L) indicate state 3B, that is, state 4. FIG. At this time, the second detection unit 10B determines that the state is normal because the state 1 passes through the state 2 and then the state 3, and the first detection unit 10A suddenly shifts from the state 1 to the state 4. Therefore, it can be determined that the state transition 18A of the first detection unit 10A is not as expected (and the states do not match), that is, the first detection unit 10A is abnormal. Then, in step 132, if the state transition 18B of the second detector 10B is as expected, the second detector 10B is normal, so the operation proceeds to step 134, and the counter 40 emits light. The alarm signal AS1 relating to the first detection section 10A supplied to the control section 39 is set to high level. Then, the light emission control section 39 turns off the LED 31 of the first detection section 10A. In the next step 136, rotation information is detected using the detection signal of the second detection section 10B. Since the LED 31 is turned off at this time, power consumption can be suppressed.
At step 134, the counter 40 sets the alarm signal AS1 to a high level and indicates to the control unit 27 that only the first detection unit 10A is abnormal, but rotation information can be detected. Alarm information (not shown) of the first detection unit 10A may be supplied. Accordingly, as an example, an administrator (not shown) can replace the first detection unit 10A at the next maintenance opportunity.

On the other hand, if the state transition 18B of the second detector 10B is not as expected in step 132, the second detector 10B is also abnormal. and AS2 are both set to high level. At this time, the light emission control unit 39 supplies alarm information (not shown) indicating that both the detection units 10A and 10B are abnormal to the control unit 27 of the motor control unit 26 in FIG. Then, the light emission control unit 39 stops the light emission of the LEDs 31 and 34, and for example, the control unit 27 informs the administrator (not shown) that the alarm information has been received. In response to this, the administrator can perform maintenance (replacement, etc.) of the detection units 10A and 10B, for example.

According to this operation, since the two detection units 10A and 10B are provided, when an abnormality occurs in one of the detection units 10A and 10B, the other detection unit 10A and 10B can continue detecting rotation information. . Further, for example, when the rotation information is detected using the detection signal of the first detection unit 10A, the LED 34 of the second detection unit 10B is turned on at twice the lighting cycle TA of the LED 31 of the first detection unit 10A. Since the presence or absence of abnormality in the detection units 10A and 10B is determined by intermittently lighting at the period TB, power consumption can be suppressed. Therefore, the frequency of maintenance such as replacement of the battery 15 can be reduced.

As described above, the encoder device EC of the present embodiment irradiates light onto the disk 6 of the rotating shaft SF (moving unit), detects the light from the disk 6, and generates detection signals MA1 and MB1 (first detection signals). a first detection unit 10A that outputs light, a second detection unit 10B that irradiates the disc 6 with light, detects the light from the disc 6, and outputs detection signals MA2 and MB2 (second detection signals), and a detection signal The encoder device includes a counter 40 (calculating section) that obtains multi-rotation information (movement information) of the rotating shaft SF using at least one of MA1, MB1 and MA2, MB2. The encoder device EC intermittently drives (lights) the first detection unit 10A and the second detection unit 10B, and sets the driving period TB (lighting period of the LED 34) of the second detection unit 10B to the first detection unit 10A. is provided with a light emission control unit 39 (control unit) that makes it longer than the drive cycle TA (lighting cycle of the LED 31). As an example, the drive period of the detection section 10A means the lighting period of the LED 31 and the sampling period of the light receiving elements 32A to 32D. Further, the method of using the encoder device EC is to intermittently drive the first detection unit 10A and the second detection unit 10B, and to drive the second detection unit 10B during at least a part of the period for obtaining the multi-rotation information of the rotary shaft SF. includes steps 102 and 104 for making the drive cycle TB of the first detector 10A longer than the drive cycle TA of the first detector 10A.

According to this embodiment, since the two detectors 10A and 10B are provided, even if an abnormality occurs in one of the detectors, the rotational position of the rotation shaft SF can be detected by using the detection signal of the other detector. The accuracy or reliability of information detection results can be improved. Moreover, since the LED 31 and the LED 34 are driven intermittently, power consumption can be suppressed. Furthermore, since the drive cycle (lighting cycle) of the LED 34 is longer than the drive cycle of the LED 31 in at least a part of the period, power consumption can be further reduced.

Further, in the present embodiment, the drive period TA of the LED 31 is set to ⅛ or less of one period of the predicted maximum rotational speed of the rotation shaft SF (½ or less of the phase difference (90°) between the detection signals MA1 and MB1). , and the drive period TB of the LED 34 is set to be more than 1 time and 2 times or less than the drive period TA of the LED 31, at least twice or One sampling of the detection signals MA1-MB2 and MA2, MB2 can be performed. Therefore, the state transition of the two sets of detection signals can be accurately detected, and if an abnormality occurs in one of the two detection units 10A and 10B during use, the occurrence of the abnormality can be accurately detected. While being recognizable, the power consumption can be further suppressed.

In addition, the following modifications are possible in the above-described embodiment. First, in step 110 in FIG. 4 of the above-described embodiment, if the detection signals MA1 and MB1 are normal, the counter 40 uses only the detection signals MA1 and MB1 (first detection signal) to calculate multiple rotations of the rotating shaft SF. You may ask for information. At this time, the LED 31 may be continuously lit and the LED 34 may be extinguished. Then, for example, if it is found by comparing the state transitions 18A and 18B that the detection signals MA1 and MB1 of the first detection section 10A are not normal, in step 136, the counter 40 detects the detection signals MA2 and MB2 (second 2 detection signal) may be used to obtain the multi-rotation information of the rotating shaft SF. At this time, the LED 34 may be continuously lit and the LED 31 may be extinguished. By this operation, power consumption can be reduced and the reliability of the rotation information can be improved.

Next, in the above embodiment, as shown in FIG. 2A, the angle between the first detection section 10A and the second detection section 10B is 90°. On the other hand, as shown in the modified example of FIG. 6A, the second detection section 10B may be arranged on the disk 6 at an angle of 180° with respect to the first detection section 10A. In this modification, it is assumed that the detection signals MA1 and MB1 obtained from the first detection section 10A when the disk 6 is rotated are two-phase rectangular wave signals shown in FIG. 6B. At this time, the detection signals MA2 and MB2 obtained from the second detection section 10B are, as shown in FIG. Become. In other words, the detection signals MA2 and MB2 are signals obtained by shifting the detection signals MA1 and MB1 by 1/2 of one cycle (180°).

In this modification, the combinations of detection signals MA1 and MB1 in state 1 (ST1) to state 4 (ST4) are the same as in the example of FIG. 3(A). On the other hand, the combinations of detection signals MA2 and MB2 in states 1 to 4 are (L, H), (L, L), (H, L) and (H, H), as shown in FIG. is different from the example of Also in this modification, normally, as shown in FIG. 6C, the LED 31 of the first detection section 10A is lit by the drive signal 31L of the period TA, and the LED 34 of the second detection section 10B is lit by the drive signal 34L of the period TB. to light up. By reading the detection signals MA1, MB1 and MA2, MB2 and comparing the states of these signals, it is possible to detect the rotation information of the rotation shaft SF and determine whether or not there is an abnormality in the detection units 10A and 10B. can.

In the above-described embodiment, as shown in FIG. 2B, two-phase detection signals MA1 and MB1 are generated from the detection signals of the two light receiving elements 32A, 32B and 32C, 32D using the analog comparators 33A and 33B. Similarly, two-phase detection signals MA2 and MB2 are generated from the detection signals of the four light receiving elements 35A to 35D. On the other hand, two-phase detection signals MA1 and MB1 may be generated by comparing the detection signals of the light receiving elements 32A and 32C and the corresponding reference signals, for example. Two-phase detection signals MA2 and MB2 can be similarly generated. In this case, the patterns 8B and 8D are omitted from the disc 6 of FIG. Therefore, the configuration of the disk 6 and the configuration of the detectors 10A and 10B can be simplified.

[Second embodiment]
A second embodiment will be described with reference to FIGS. 7 and 8. FIG. 7 and 8, portions corresponding to those in FIGS. 4 and 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.
The encoder device of this embodiment is the same as the encoder device EC shown in FIGS. 1 and 2(A) and (B), and the measurement target of the encoder device EC is the rotating shaft SF of FIG. An example of how to use the encoder device EC of this embodiment will be described below with reference to the flowchart of FIG. Its usage includes a method of further reducing power consumption when the rotating shaft SF is stopped. FIG. 8A shows an example of changes in the detection signals MA1 and MB1 of the first detection section 10A and the detection signals MA2 and MB2 of the second detection section 10B in this embodiment. In FIG. 8A, detection signals MA1, MB1 and MA2, MB2 are continuously in state 2 (ST2). When the same state continues in this manner, it can be considered that the rotating shaft SF is stopped.

First, in step 102 of FIG. 7, the LED 31 of the first detection section 10A is turned on by the drive signal 31L of the first cycle TA as shown in FIG. For example, it is lit by the drive signal 34L of the second period TB which is double. Then, in step 106, the counter 40 detects the detection signals MA1, MB1 and MA2, MB
Read 2. Further, at step 108, counter 40 reads the next detection signals MA1, MB1 and MA2, MB2. Then, in step 110, the counter 40 obtains multiple rotation information (rotation information) of the rotation shaft SF using the read detection signals MA1 and MB1 of the first detection unit 10A for a plurality of times, and stores the multi-rotation information (rotation information) in the storage unit 14. . Note that the detection signals MA2 and MB2 may be used when obtaining the multi-rotation information.

Next, at step 142, the counter 40 compares the states of the detection signals read last time and this time from the first detection section 10A and the second detection section 10B. Then, in step 144, if the states of the two detection signals do not match, it is assumed that the rotating shaft SF is rotating, and the operation returns to step . On the other hand, in step 144, if the states of the two detection signals match as in the second state 2 (ST2) in FIG. 8A, it is assumed that the rotating shaft SF is stopped. As such, operation proceeds to step 146 . Then, the counter 40 sets the stationary state signal AS3 supplied to the light emission control section 39 to high level. In response to this, as shown at time t4 in FIG. 8B, the light emission control section 39 continuously changes the drive signal 34L to the low level, thereby extinguishing the LED 34 of the second detection section 10B. Furthermore, since the rotary shaft SF is stopped, the period of the drive signal 31L may be set wider to the second period TB, and the LED 31 of the first detection section 10A may be lit in the second period TB. Instead of turning off the LED 34, the lighting period of the LED 34 may be set longer than the period TB, such as an integer multiple such as twice or three times the period TB.

Then, at step 148, the counter 40 reads the detection signals MA1 and MB1 of the first detection unit 10A, and at step 150 whether the state numbers of the detection signals MA1 and MB1 twice (current and previous) match. That is, it checks whether or not the rotating shaft SF continues to stop. If the two states match, the process proceeds to step 148 to read the detection signal of the first detection section 10A. Also, in step 150, if the two states do not match, as at time t5 (when transitioning from state 2 to state 3) in FIG. In this case, the counter 40 returns the stationary state signal AS3 to the low level, but the rotational speed of the rotating shaft SF may rapidly increase. Therefore, the light emission control section 39 sets the drive signals 31L and 34L to a period shorter than the period TA, thereby lighting the LEDs 31 and 34 of the detection sections 10A and 10B in a period shorter than the first period TA. Then, in step 154, the counter 40 detects the detection signals MA1 and MB1 of the first detection section 10A (or the detection signals MA2 and MB2 of the second detection section 10B) in synchronization with the sampling signals SSA and SSB corresponding to the lighting period. load. Then, at step 156, the counter 40 calculates the rotation information of the rotation shaft SF using the read detection signals MA1, MB1, etc., and causes the storage unit 14 to store the obtained rotation information. After that, as an example, the process proceeds to step 112 in FIG. 4 to determine which of the first detection section 10A and the second detection section 10B has an abnormality. Note that instead of proceeding to step 112, the process may return to step 154 in FIG.

According to the method of using the encoder device EC of the present embodiment, when the state (combination of states) of the detection signals of the first detection section 10A and the second detection section 10B is constant and the period TB (predetermined period) has passed, A step 146 of setting a stationary state signal AS3 indicating that the rotating shaft SF is stationary to a high level, and a step 146 of further lengthening the drive cycle of the LED 34 of the second detection section 10B according to the stationary state signal AS3. and When the rotating shaft SF stops in this way, the LED 34 of the second detection unit 10B is turned off or the lighting cycle is set long. Electric power can be further suppressed.

Further, according to the present embodiment, when the rotating shaft SF starts to rotate, the LEDs 31 and 34 of the first detection section 10A and the second detection section 10B are turned on at a cycle shorter than the first cycle TA (step 152). ). Therefore, even if the rotational speed of the rotating shaft SF increases rapidly, multi-rotation information and the like can be detected with high accuracy.
In this embodiment, in step 144, it is determined that the rotary shaft SF is stopped when the state of the detection signals of the detection units 10A and 10B remains the same twice. However, it may be determined that the rotating shaft SF is stopped when the same state of the detection signal continues, for example, n times (n is a predetermined integer equal to or greater than 3).

In the above-described embodiment, the counter 40 uses the detection signals MA1 to MB2 to obtain the multi-rotation information. The first detection signal) may be used to obtain multi-rotation information. The detection signals MA2 and MB2 of the second detection unit 10B are also supplied to the light emission control unit 39. For example, when the counter 40 determines that the detection signals MA1 and MB1 are abnormal, the counter 40 In response to the alarm signal, the light emission control section 39 (control section) may obtain the multi-rotation information using the detection signals MA2 and MB2 (second detection signals) of the second detection section 10B.
Further, in the second detection section 10B, at least one of the irradiation of light from the LED 34 and the detection of the detection signals MA2 and MB2 by the light emission control section 39 may be performed in an intermittent drive cycle.
Further, the counter 40 can also be regarded as a control section that detects an abnormality in the detection sections 10A and 10B based on a change in the combination of the first and second detection signals.

[Third Embodiment]
A third embodiment will be described with reference to FIGS. 9 and 10. FIG. 9 and 10, parts corresponding to those in FIGS. 2 and 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.
FIG. 9A is a plan view showing the disk 6 and detection units 10C and 10D of the encoder device ECA of this embodiment, and FIG. 9B shows the detection units 10C and 10D and the detection circuit unit 13 and the like of the encoder device ECA. It is a diagram. In FIG. 9A, on the surface of the disc 6, a reflective annular pattern 8E is formed inside the patterns 8A to 8D concentrically with the patterns 8A to 8D. A second detection section 10D is arranged at an angular interval of 90° with respect to the first detection section 10C so as to face the disc 6 .

In FIG. 9B, the first detection unit 10C includes an LED 31 that illuminates the patterns 8A to 8D and 8E of the disc 6, light receiving elements 32A to 32D that receive reflected light from the patterns 8A to 8D, and a pattern 8E. and a light-receiving element 32E for receiving reflected light from. Since the pattern 8E has a continuous annular shape, the detection signal of the light receiving element 32E is at a high level while the LED 31 is emitting light. Therefore, the detection signal of the light receiving element 32E is referred to as a light emission signal 31LS of the LED 31. FIG. The light emission signal 31LS is supplied to the counter 40A. The counter 40A can recognize the presence or absence of abnormality of the LED 31 from the light emission signal 31LS. Other configurations of the first detection section 10C are the same as those of the first detection section 10A of FIG. 2B, and detection signals MA1 and MB1 are also supplied to the counter 40A.

The second detection unit 10D also includes an LED 34 that illuminates the patterns 8A to 8D and 8E of the disc 6, light receiving elements 35A to 35D that receive reflected light from the patterns 8A to 8D, and light reflected from the pattern 8E. and a light receiving element 35E for receiving light. The detection signal of the light receiving element 32E is at a high level while the LED 34 is emitting light. A detection signal (hereinafter referred to as a light emission signal of the LED 34) 34LS of the light receiving element 32E is supplied to the counter 40A. The counter 40A can recognize the presence or absence of abnormality in the LED 34 from the light emission signal 34LS. Other configurations of the second detection section 10D are the same as those of the second detection section 10B in FIG. 2B, and detection signals MA2 and MB2 are also supplied to the counter 40A. The LEDs 31 and 34 are intermittently lighted by the light emission control section 39A.

The counter 40A reads the detection signals MA1, MB1 and MA2, MB2 in synchronization with the sampling signals SSA, SSB, processes the read detection signals MA1, MB1, MA2, MB2 to obtain multi-rotation information (rotation information). Further, the counter 40A determines that there is an abnormality in the LED 31 or 34 when the light emission signal 31LS or 34LS becomes low level, and raises the alarm signal AS4 or AS5 supplied to the light emission control section 39A to high level. set. In response to this, the light emission control unit 39A sets the driving power of the LED 31 or 34 to 0, respectively. As a result, wasteful power consumption can be suppressed. Other configurations and effects are the same as those of the first embodiment.

An example of how to use the encoder device ECA of this embodiment will be described with reference to FIG. Also in this embodiment, as shown in FIG. 10C, the cycle of the drive signal 31L for the LED 31 is set to the first cycle TA, and the cycle of the drive signal 34L for the LED 34 is set to the second cycle TB. Thereby, the LEDs 31 and 34 intermittently emit light in the first period TA and the second period TB, respectively. After that, for example, at time t4, when the detection signals MA1, MB1 and MA2, MB2 repeat the same state 2 (ST2), it is determined that the rotating shaft SF has stopped, the LED 31 is turned on at the second period TB, LED 34 goes out.

Thereafter, for example, when the light emission signal 31LS becomes low level at time t6, the counter 40A determines that the LED 31 of the first detection unit 10C is abnormal, and sets the alarm signal AS4 to high level. . At this time, the levels of the detection signals MA1 and MB1 may become unstable or unstable. In response to this, the light emission control unit 39A sets the drive signal 31L to the low level to completely turn off the LED 31, sets the drive signal 34L to the second period TB, and turns on the LED 34 in the second period TB. Further, the counter 40 uses the detection signals MA2 and MB2 of the second detection section 10D to obtain multi-rotation information of the rotating shaft SF. As a result, if the output of the LED 31 of the first detection unit 10C decreases while the rotation shaft SF is stopped, the LED 34 of the second detection unit 10D is intermittently driven to detect the rotation axis using the detection signals MA2 and MB2. SF multi-rotation information can be continuously detected. Furthermore, when the states of the detection signals MA2 and MB2 change at time t7 after that and the rotation of the rotation shaft SF is detected, the period of the drive signal 34L is set short, and the LED 34 is operated at a shorter period. It can be lit.

As described above, according to the encoder device ECA of the present embodiment, since the light-receiving elements 32E and 35E for monitoring the outputs of the LEDs 31 and 34 of the detection units 10C and 10D are provided, the output of the LEDs 31 or 34 is lowered due to a failure or the like. In some cases, the decrease in output can be recognized. In this case, by setting the power supplied to the faulty LED 31 or 34 to 0 and intermittently lighting the non-faulty LED 31 or 34, wasteful power consumption can be suppressed and the rotation information of the rotation shaft SF can be reduced. Detection can continue. Further, in this embodiment, when the outputs of the LEDs 31 and 34 decrease and both the alarm signals AS4 and AS5 are set to a high level, the light emission control section 39A outputs alarm information indicating that there is an abnormality in the encoder device ECA. You may transmit to the motor control part 26 of FIG. After that, maintenance such as replacement of the detectors 10C and 10D is performed.

Also in this embodiment, the angle between the first detection section 10C and the second detection section 10D may be set to 180°.
In the above-described embodiment, both the LEDs 31 and 34 of the first detection units 10A and 10C and the second detection units 10B and 10D emit light intermittently. You may let Also, when one of the LEDs 31 and 34 is intermittently lit, the other of them may be lit continuously. Even in this case, power consumption can be suppressed.

In the above-described embodiment, the position detection system 2 detects the rotational position information (movement information) of the rotating shaft SF (moving portion) as the position information. You can detect one. The encoder devices EC and ECA may include rotary encoders or linear encoders. Also, the encoder devices EC and ECA are reflective encoders, but may be transmissive encoders.

[Driving device]
An example of the driving device will be described. FIG. 11 is a diagram showing an example of the driving device MTR. In the following description, the same reference numerals are given to components that are the same as or equivalent to those of the above-described embodiment, and descriptions thereof are omitted or simplified. This drive device MTR is a motor device including an electric motor. The driving device MTR has a rotating shaft SF, a main body (driving portion) BD that rotationally drives the rotating shaft SF, and an encoder device EC that detects rotational position information of the rotating shaft SF. Note that an encoder device ECA may be provided instead of the encoder device EC (the same applies hereinafter).

The rotating shaft SF has a load-side end SFa and a non-load-side end SFb. The load side end SFa is connected to another power transmission mechanism such as a speed reducer. A disk 6 is fixed to the non-load side end SFb via a fixing portion. Along with fixing the disk 6, an encoder device EC is attached. The encoder device EC is an encoder device according to the above-described embodiments, modifications, or combinations thereof.

In this driving device MTR, the motor control section 26 shown in FIG. 1 controls the main body section BD using the detection result of the encoder device EC. Since the drive device MTR eliminates or reduces the need for battery replacement of the encoder device EC, maintenance costs can be reduced. The drive device MTR is not limited to a motor device, and may be another drive device having a shaft portion that rotates using hydraulic or pneumatic pressure.

[Stage device]
An example of the stage device will be described. FIG. 12 shows the stage device STG. This stage device STG has a configuration in which a rotary table (moving object) TB is attached to the load-side end portion SFa of the rotating shaft SF of the driving device MTR shown in FIG. In the following description, the same reference numerals are given to components that are the same as or equivalent to those of the above-described embodiment, and descriptions thereof are omitted or simplified.

When the stage device STG drives the driving device MTR to rotate the rotating shaft SF, this rotation is transmitted to the rotating table TB. At that time, the encoder device EC detects the angular position and the like of the rotation shaft SF. Therefore, by using the output from the encoder device EC, the angular position of the rotary table TB can be detected. A speed reducer or the like may be arranged between the load-side end SFa of the drive device MTR and the turntable TB.

Since the stage device STG requires less or no need to replace the battery of the encoder device EC, maintenance costs can be reduced. Note that the stage device STG can be applied to, for example, a rotary table or the like provided in a machine tool such as a lathe.
[Robot device]
An example of a robot device will be described. FIG. 13 is a perspective view showing the robot device RBT. Note that FIG. 13 schematically shows a portion (joint portion) of the robot device RBT. In the following description, the same reference numerals are given to components that are the same as or equivalent to those of the above-described embodiment, and descriptions thereof are omitted or simplified. This robot device RBT has a first arm AR1, a second arm AR2, and a joint JT. The first arm AR1 is connected to the second arm AR2 via the joint JT.

The first arm AR1 has an arm portion 91, a bearing 91a, and a bearing 91b. The second arm AR2 has an arm portion 92 and a connecting portion 92a. The connecting portion 92a is arranged between the bearing 91a and the bearing 91b in the joint portion JT. The connecting portion 92a is provided integrally with the rotating shaft SF2. The rotating shaft SF2 is inserted into both the bearing 91a and the bearing 91b at the joint JT. The end of the rotating shaft SF2 on the side inserted into the bearing 91b penetrates the bearing 91b and is connected to the speed reducer RG.

The speed reducer RG is connected to the drive device MTR, reduces the rotation of the drive device MTR to, for example, 1/100, and transmits it to the rotation shaft SF2. Although not shown in FIG. 13, the load-side end SFa of the rotating shaft SF of the driving device MTR is connected to the speed reducer RG. Further, the disk 6 of the encoder device EC is attached to the opposite end SFb of the rotary shaft SF of the drive device MTR.

When the robot device RBT drives the driving device MTR to rotate the rotating shaft SF, this rotation is transmitted to the rotating shaft SF2 via the speed reducer RG. The rotation of the rotation shaft SF2 rotates the connecting portion 92a integrally, thereby rotating the second arm AR2 with respect to the first arm AR1. At that time, the encoder device EC detects the angular position and the like of the rotation shaft SF. Therefore, the angular position of the second arm AR2 can be detected from the output from the encoder device EC.

Since the robot device RBT does not or rarely needs to replace the battery of the encoder device EC, maintenance costs can be reduced. Robot device RBT is not limited to the configuration described above, and drive device MTR can be applied to various robot devices having joints.

2 Position detection system 3 Multi-rotation information detection unit 4 Angle detection unit 6 Disk 8A to 8D Semi-annular pattern 8E Ring-shaped pattern 10A, 10C First detection unit DESCRIPTION OF SYMBOLS 10B, 10D... 2nd detection part 13... Detection circuit part 14... Storage part 15... Battery 22... Signal synthesis part 26... Motor control part 31, 34... LED, 32A-32E, 35A-35E... Light receiving element 33A, 33B, 36A, 36B analog comparator 39, 39A light emission controller 40, 40A counter EC, ECA encoder device SF rotary shaft M motor AR1 first arm , AR2... second arm, MTR... driving device, RBT... robot device, STG... stage device

Claims (21)

a first detector that irradiates a moving part with light, detects the light from the moving part, and outputs a first detection signal;
a second detection unit that irradiates the moving unit with light, detects the light from the moving unit, and outputs a second detection signal;
an encoder device comprising: an arithmetic unit that obtains movement information of the moving unit from at least one of the first detection signal and the second detection signal,
An encoder device comprising: a control section that intermittently drives the first detection section and the second detection section, and that makes the drive cycle of the second detection section longer than the drive cycle of the first detection section. The first detection unit has a first light emitting unit that emits light to the pattern provided on the moving unit and a first light receiving unit that receives light from the pattern,
The second detection unit is arranged at a position different from the first detection unit with respect to the pattern, and includes a second light emitting unit that emits light to the pattern and a second light receiving unit that receives light from the pattern. The encoder device according to claim 1, comprising: The first detection unit outputs a first set of detection signals having phases different from each other due to the movement of the moving unit,
3. The encoder device according to claim 2, wherein the second detection section outputs a second set of detection signals that change in different phases with respect to the first set of detection signals due to the movement of the moving section. 4. The encoder device according to claim 3, wherein the second set of detection signals differs in phase from the first set of detection signals by 1/2 cycle or 1/4 cycle according to the movement of the moving part. The control unit causes the first light emitting unit to emit light at least twice during a period corresponding to the phase difference between the first set of detection signals,
5. The encoder device according to claim 3, wherein the drive cycle of said second light emitting unit is set to be twice the drive cycle of said first light emitting unit. 6. The controller according to any one of claims 3 to 5, wherein the control unit shortens the drive cycle of the second detection unit according to a combination of states of the first set and the second set of detection signals detected by movement of the moving unit. or the encoder device according to claim 1. 6. The method according to any one of claims 3 to 5, wherein the control unit further sets the driving cycle of the second detection unit to be longer after a predetermined period of time has elapsed with the combination of states of the first set and the second set of detection signals being constant. An encoder device according to any one of the preceding clauses. The encoder device according to claim 7, wherein the control section turns off the second light emitting section. When the combination of the states of the first set of detection signals changes, the control unit shortens the drive cycle of the first detection unit and shortens the drive cycle of the second detection unit. The encoder device according to claim 7 or 8, which is set to be the same as the period. The control unit compares the states of the first detection signal and the second detection signal, thereby obtaining at least one of the first detection signal and the second detection signal as a detection signal for obtaining movement information of the moving unit. 2. Encoder apparatus according to claim 1, wherein one is selected. The encoder device according to claim 1, wherein the control section detects an abnormality in at least one of the first and second detection sections by comparing states of the first detection signal and the second detection signal. 2. The encoder device according to claim 1 , wherein the control section obtains the movement information using the second detection signal according to states of the first detection signal and the second detection signal. 13. The encoder device according to claim 12 , wherein the second detection section performs at least one of the irradiation of the light and the detection of the light in an intermittent driving cycle. 14. The encoder device according to claim 13 , wherein the control section shortens a driving cycle of the second detection section and obtains the movement information using the second detection signal. The encoder device according to claim 1 , wherein the control section detects an abnormality of the first or second detection section according to states of the first detection signal and the second detection signal caused by movement of the moving section. A second power supply comprising a first power supply and a primary battery or a secondary battery,
The control unit according to any one of claims 1 to 15 , wherein when the first power supply is off, the control unit drives the first detection unit and the second detection unit using power of the second power supply. Encoder device. the moving part has a rotating shaft,
17. The encoder device according to any one of claims 1 to 16 , wherein the calculation unit obtains multi-rotation information of the rotating shaft as the movement information. an encoder device according to any one of claims 1 to 17 ;
a power source that supplies power to the moving part;
A drive device comprising: a moving object;
and a driving device according to claim 18 , which moves the moving object. A driving device according to claim 18 ;
and an arm relatively moved by the drive device. a first detector that irradiates a moving part with light, detects the light from the moving part, and outputs a first detection signal;
a second detection unit that irradiates the moving unit with light, detects the light from the moving unit, and outputs a second detection signal;
A control method for an encoder device comprising: a calculation unit that obtains movement information of the moving unit from at least one of the first detection signal and the second detection signal,
A method of controlling an encoder device, comprising: intermittently driving the first detection section and the second detection section; and making the drive cycle of the second detection section longer than the drive cycle of the first detection section.

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