JP2017227457A - Detecting device, and detecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make less rigid, even when a sensor element is to be intermittently driven, the constraint between the period of the intermittent drive and the measurable range than what the conventional configuration is subjected to.SOLUTION: A detecting device is equipped with a mode switchover unit 702 that switches over the detection mode to a low speed mode or a high speed mode in accordance with the transition of the state value detected by a state value detecting unit 701, and a displacement detecting unit 703 that detects the rotational direction and the rotational quantity of a rotation shaft 10 from the transition of the state value detected by the state value detecting unit 701 when the detection mode is the low speed mode and, when the detection mode is the high speed mode, supposes that the rotational direction of the rotation shaft 10 is the same as the rotational direction detected immediately before and detects the rotational quantity of the rotation shaft 10 from the transition of the state value detected by the state value detecting unit 701.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a detection apparatus and a detection method for detecting displacement of an object.

Conventionally, an optical or magnetic rotary encoder has been used to detect the rotation of the rotating shaft (see, for example, Patent Document 1). In many cases, the optical sensor element or magnetic sensor element (MR sensor element, Hall sensor element, etc.) mounted on the rotary encoder consumes electric power.
On the other hand, gas meters used for LPG or city gas, and home or business meters such as water meters are required to operate for a long period of time such as 10 years using batteries. Therefore, the circuit in the meter is required to operate with a very low current consumption. Therefore, in the rotary encoder mounted on these meters, the power consumption is reduced by intermittently driving the sensor element.

JP 2002-213944 A

However, in the conventional rotary encoder, when the sensor element is intermittently driven, there is a problem that the upper limit for the rotation speed of the rotation shaft is determined by the sampling theorem. Therefore, the period of intermittent driving, that is, power consumption, and a measurable rotational speed are in a trade-off relationship.
In addition, the meter requires a high resolution at a low flow rate (when the rotating shaft rotates at a low speed) by the measuring method, and must ensure volume measurement accuracy up to the rated maximum flow rate. However, the conventional rotary encoder does not satisfy both the above conditions. Note that the resolution of the meter may be relatively low when the flow rate is high (when the rotary shaft rotates at high speed).
In addition, the above-described problem is not limited to the rotary encoder, and similarly exists for a linear encoder that detects the movement of an object.

  The present invention has been made to solve the above-described problems. Even when the sensor element is intermittently driven, the restriction between the period of the intermittent drive and the measurable range is limited to the conventional configuration. It aims at providing the detection apparatus which can ease conditions.

  The detection device according to the present invention is arranged so as to be out of phase, and is intermittently driven, and outputs a signal according to the displacement of the object, and indicates the presence or absence of a signal from the one set of sensor elements. When the state value detection unit that detects the state value, the mode switching unit that switches the detection mode to the low speed mode or the high speed mode from the transition of the state value detected by the state value detection unit, and the detection mode is the low speed mode, When the displacement direction and amount of the object are detected from the transition of the state value detected by the state value detection unit, and the detection mode is the high speed mode, the displacement direction of the object is the same as the displacement direction detected immediately before. It is provided with a displacement detection unit that detects the amount of displacement of the object from the transition of the state value detected by the state value detection unit.

  According to the present invention, since it is configured as described above, even when the sensor element is intermittently driven, the constraint condition between the cycle of the intermittent drive and the measurable range is relaxed compared to the conventional configuration. Can do.

It is a figure which shows the structural example of the rotary encoder which concerns on Embodiment 1 of this invention. It is a figure which shows the structural example of the calculating part in Embodiment 1 of this invention. It is a flowchart which shows the operation example of the calculating part in Embodiment 1 of this invention. 4A and 4B are diagrams illustrating examples of signals obtained when the first and second photosensor elements are continuously driven, and a signal waveform when the rotation shaft rotates in the forward direction and a signal waveform when the rotation shaft rotates in the reverse direction. FIG. It is a figure which shows an example of the relationship between the signal and state value which are obtained when the 1st, 2nd optical sensor element is driven continuously. It is a figure for demonstrating calculation of the rotation amount in the calculating part in Embodiment 1 of this invention. It is a figure explaining operation | movement of the calculating part in Embodiment 1 of this invention, Comprising: It is a figure which shows the transition diagram of a state value. It is a figure explaining operation | movement of the calculating part in Embodiment 1 of this invention, Comprising: It is a figure which shows the relationship between a transition of a state value, rotation amount, and a rotation direction. It is a figure which shows the structural example of the calculating part in Embodiment 2 of this invention. It is a figure for demonstrating the setting of the threshold value used by the calculating part in Embodiment 2 of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1 FIG.
1 is a diagram showing a configuration example of a rotary encoder according to Embodiment 1 of the present invention. Below, the case where an optical rotary encoder is used as a detection apparatus is shown.
The rotary encoder is mounted on a home or business meter such as a gas meter or a water meter, for example, and detects the rotation (displacement) of the rotary shaft (object) 10. As shown in FIG. 1, this rotary encoder includes a light source 1, a lens 2, a rotating disk 3, a fixed slit 4, a set of optical sensor elements (sensor elements) 5 and 6, and a calculation unit 7. In addition, the structure except the calculating part 7 among the structures of the rotary encoder which concerns on Embodiment 1 is the same as that of the conventional rotary encoder.

The light source 1 emits light.
The lens 2 is disposed opposite to the light emitting surface of the light source 1 and converts light emitted from the light source 1 into parallel light. The light converted into parallel light by the lens 2 is applied to the outer peripheral portion of the rotating disk 3.

  The rotating disk 3 is a disk-like member attached to the rotating shaft 10 and rotates as the rotating shaft 10 rotates. The rotary disk 3 is provided with an insertion hole 301 into which the rotary shaft 10 is inserted at the center, and slits 302 are provided at regular intervals on the outer periphery. The surface of the rotating disk 3 (the surface on the lens 2 side) is irradiated with light from the light source 1 via the lens 2 on the outer peripheral portion.

  The fixed slit 4 is disposed opposite to the outer peripheral portion of the back surface of the rotating disk 3. The position of the fixed slit 4 is fixed. The fixed slit 4 is provided with two slits 401 and 402 at positions that can face the slit 302 provided on the rotary disk 3. The two slits 401 and 402 are arranged at intervals such that the phases of the signals output from the optical sensor elements 5 and 6 are shifted by a quarter period.

  The optical sensor element 5 is the back surface of the fixed slit 4 (the surface opposite to the rotating disk 3), and is disposed to face one slit 401 provided in the fixed slit 4. The optical sensor element 5 receives light and converts it into a signal corresponding to the intensity (hereinafter referred to as a first signal). The first signal obtained by the optical sensor element 5 is output to the calculation unit 7.

The optical sensor element 6 is the back surface of the fixed slit 4 and is disposed opposite to the other slit 402 of the fixed slit 4. The optical sensor element 6 receives light and converts it into a signal corresponding to the intensity (hereinafter referred to as a second signal). The second signal obtained by the optical sensor element 6 is output to the calculation unit 7.
Note that the optical sensor elements 5 and 6 operate by intermittent driving with the same cycle.

  The calculation unit 7 detects the rotation of the rotating shaft 10 based on the first and second signals from the optical sensor elements 5 and 6. As shown in FIG. 2, the calculation unit 7 includes a state value detection unit 701, a mode switching unit 702, and a displacement detection unit 703. The arithmetic unit 7 is realized by a processing circuit such as a system LSI, a CPU that executes a program stored in a memory, or the like.

  The state value detector 701 detects a state value indicating the presence or absence of the first and second signals from the optical sensor elements 5 and 6. For example, the state value detection unit 701 detects the state value “10” when the first signal is present and the second signal is absent. The state value detection unit 701 detects the state value “11” when the first signal is present and the second signal is present. Further, the state value detection unit 701 detects the state value “01” when there is no first signal and there is a second signal. The state value detection unit 701 detects the state value “00” when the first signal is absent and the second signal is absent.

  The mode switching unit 702 switches the detection mode in the displacement detection unit 703 to the low speed mode or the high speed mode from the transition of the state value detected by the state value detection unit 701. At this time, when the detection mode is the low-speed mode, the mode switching unit 702 causes the state value detected by the state value detection unit 701 to transition two before or after the state value detected immediately before. In such a case, the detection mode is switched to the high speed mode. In addition, the mode switching unit 702 switches the detection mode to the high-speed mode, and then the state value detected by the state value detection unit 701 is one previous or one before the state value detected immediately before for a certain period. When the transition is performed later or when the transition is not performed with respect to the state value detected immediately before, the detection mode is switched to the low speed mode. In addition, the mode switching unit 702 sets the detection mode to the low speed mode in the initial state.

  The displacement detection unit 703 detects the rotation direction (displacement direction) and the rotation amount (displacement amount) of the rotating shaft 10 from the transition of the state value detected by the state value detection unit 701 when the detection mode is the low speed mode. . Further, when the detection mode is the high speed mode, the displacement detection unit 703 assumes that the rotation direction of the rotary shaft 10 is the same as the rotation direction detected immediately before, and the state value detected by the state value detection unit 701 The amount of rotation of the rotary shaft 10 is detected from the transition of.

Next, an example of operation performed by the calculation unit 7 of the rotary encoder according to the first embodiment will be described with reference to FIGS.
FIG. 4 is a diagram illustrating an example of a signal waveform obtained when the optical sensor elements 5 and 6 are continuously driven. 4A and 4B, the upper waveform indicates the first signal, and the lower waveform indicates the second signal. Then, as shown in FIG. 5, the state value is obtained from the signal waveforms of the first and second signals. On the other hand, when the optical sensor elements 5 and 6 are intermittently driven, the optical sensor elements 5 and 6 can read only a value for each period in which intermittent driving is performed, among signal waveforms by continuous driving. Therefore, in the conventional rotary encoder, in order to detect the rotation of the rotary shaft 10, it is necessary to intermittently drive the optical sensor elements 5 and 6 at a cycle shorter than the cycle T shown in FIG. Therefore, in the rotary encoder according to the first embodiment, when the rotation of the rotary shaft 10 is fast, it is assumed that the rotation direction does not change in the middle, and the rotation is detected from the change in the state value, whereby the intermittent Relax the constraint between the driving period and measurable range.

  In the operation example by the calculation unit 7 of the rotary encoder according to the first embodiment, as shown in FIG. 3, first, the mode switching unit 702 sets the detection mode in the displacement detection unit 703 to the low speed mode (step ST301). .

  Next, the state value detection unit 701 detects a state value indicating the presence or absence of the first and second signals from the optical sensor elements 5 and 6 (step ST302). That is, the state value detection unit 701 detects the state value using the first and second signals obtained from the optical sensor elements 5 and 6 for each cycle in which the optical sensor elements 5 and 6 operate.

  Next, mode switching section 702 determines whether or not the state value detected by state value detecting section 701 has shifted two before or after the state value detected immediately before (step ST303).

  In this step ST303, when the mode switching unit 702 determines that the detected state value has transitioned two times before or after the immediately preceding state value, the mode switching unit 702 switches the detection mode to the high speed mode (step ST304). ).

  On the other hand, in step ST303, when the mode switching unit 702 determines that the detected state value has not transitioned to the immediately preceding state value by two before or after, the detection mode is the low speed mode. The sequence proceeds to step ST305.

  Next, the displacement detection unit 703 determines whether the detection mode is the high speed mode (step ST305).

  In step ST305, when the displacement detection unit 703 determines that the detection mode is not the high speed mode (the low speed mode), the rotation of the rotary shaft 10 is determined based on the transition of the state value detected by the state value detection unit 701. The direction and amount of rotation are detected (step ST306). The rotation detection process in the low speed mode by the displacement detection unit 703 is the same as the process in the conventional detection device. Thereafter, the sequence proceeds to step ST308.

  For example, when the state value transitions from “10” to “00”, in the low speed mode, the displacement detection unit 703 detects that the rotation direction of the rotation shaft 10 is the reverse rotation direction and the rotation amount is 1. In this case, in the state value transition 601 shown in FIG. 6, the rotation direction and the rotation amount are correctly detected. On the other hand, in the state value transitions 602 to 604 shown in FIG. 6, the rotation direction and the rotation amount are not correctly detected. That is, in the rotation detection process in the low speed mode, the absolute value of the rotation amount within the detection cycle by the state value detection unit 701 needs to be 1 or less.

  On the other hand, in step ST305, when the displacement detection unit 703 determines that the detection mode is the high speed mode, the state detection is performed assuming that the rotation direction of the rotary shaft 10 is the same as the rotation direction detected immediately before. The amount of rotation of the rotating shaft 10 is detected from the transition of the state value detected by the unit 701 (step ST307).

  For example, when the state value transitions from “10” to “00”, in the high-speed mode, the displacement detection unit 703 assumes that the rotation direction of the rotation shaft 10 is the same as the previous rotation direction, Accordingly, the rotation amount is detected to be 1 or 3. In this case, the rotation amount is correctly detected in the state value transitions 601 and 602 shown in FIG. On the other hand, in the state value transitions 603 and 604 shown in FIG. 6, the rotation amount is not correctly detected. That is, in the rotation detection process in the high-speed mode, the absolute value of the rotation amount within the detection cycle by the state value detection unit 701 needs to be 3 or less.

  Next, the mode switching unit 702 detects that the state value detected by the state value detecting unit 701 has changed one time before or after the state value detected immediately before or has been detected immediately before for a certain period. It is determined whether there is no transition with respect to the state value (step ST308).

  In this step ST308, when the mode switching unit 702 determines that the detected state value has changed with respect to the immediately preceding state value for a certain period, but has not changed before or after. The detection mode remains the high speed mode, and the sequence returns to step ST302.

  On the other hand, in step ST308, the mode switching unit 702 determines whether the detected state value has shifted to the immediately preceding state value or the immediately preceding state value for a certain period of time or has been detected immediately before. If it is determined that there is no transition, the detection mode is switched to the low speed mode (step ST309). Thereafter, the sequence returns to step ST302.

FIG. 7 shows a state value transition diagram. FIG. 7 shows the case where the rotating shaft 10 rotates forward, but the same applies to the case where the rotating shaft 10 rotates backward. In FIG. 7, a broken line 71 indicates a position where the rising edge of the first signal is detected, and a broken line 72 indicates a position where the falling edge of the first signal is detected. FIG. 8 shows the relationship between the transition of the state value and the amount and direction of rotation of the rotating shaft 10. In the column of the rotation direction and the rotation amount in FIG. 8, positive / negative indicates the rotation direction (positive is the positive rotation direction, negative is the reverse rotation direction), and the numerical value indicates the rotation amount. Moreover, the gray part in the column at the time of low speed mode has shown the place which can detect a rotation direction in low speed mode.
7 and 8, the rotation of the rotating shaft 10 is slow (when the period T shown in FIG. 5 is longer than the period of intermittent driving), and the state value detected by the state value detecting unit 701 is 1 to the adjacent state value. When transitioning one by one, the detection mode is set to the low speed mode, and the rotation direction and the rotation amount are detected by detecting the rise and fall of the first and second signals as in the conventional detection device.

For example, in FIG. 7, when the state value transitions from “00” to “10” immediately before, the first signal transitions from the absence state to the present state and straddles the broken line 71. Therefore, the displacement detection unit 703 detects the rising edge of the first signal. In addition, when the state value transitions from “11” to “01” which is one before, the first signal transitions from the present state to the none state and crosses the broken line 72, so that the displacement The detection unit 703 detects the falling edge of the first signal. When the state value transitions from “10” to the previous “11” and from “01” to the previous “00”, there is no change in the first signal. The detection unit 703 does not detect the rise and fall of the first signal.
The displacement detection unit 703 similarly detects the rise and fall of the second signal, and detects that the rotation direction and the rotation amount are +1 from the rise and fall of the first and second signals. .

  On the other hand, when the rotation of the rotating shaft 10 becomes faster (when the cycle T shown in FIG. 5 is shorter than the cycle of intermittent driving), the state value detected by the state value detection unit 701 is not a transition to an adjacent state value. , Some state values are skipped and transition is made. Therefore, in such a case, it is assumed that the detection mode is the high-speed mode, and the rotation direction of the rotary shaft 10 does not change midway (the same direction as that at the low speed). The amount of rotation is detected by detecting the falling edge.

For example, in FIG. 7, when the state value transitions from “00” to “11” which is two before, as shown in FIG. 8, is the rotation direction and the rotation amount +2 in the low speed mode? I cannot figure out if it is 2. Therefore, in this case, it is assumed that the detection mode is switched to the high speed mode and the rotation direction is the same as the immediately preceding rotation direction (forward rotation direction). In this case, since the broken line 71 is straddled, the displacement detection unit 703 detects the rise of the first signal.
The displacement detection unit 703 similarly detects the rise and fall of the second signal, and detects that the rotation direction and the rotation amount are +2 from the rise and fall of the first and second signals. .

Similarly, for example, in FIG. 7, when the state value transitions from “00” to “01” three times before, assuming that the rotation direction is the same as the previous positive rotation direction, the broken lines 71 and 72 are Since it is straddling, the displacement detector 703 detects the rise and fall of the first signal.
The displacement detection unit 703 similarly detects the rise and fall of the second signal, and detects that the rotation direction and the rotation amount are +3 from the rise and fall of the first and second signals. .
The same applies to other cases.

  Here, conventionally, there is only one state value transition pattern capable of detecting the rotation of the rotating shaft 10, that is, only a pattern in which the state value transitions to an adjacent state value. On the other hand, in the rotary encoder according to the first embodiment, the number of transition patterns of state values that can detect the rotation of the rotating shaft 10 can be increased to three. That is, in the rotary encoder according to the first embodiment, what is the pattern of transition to adjacent state values, the pattern of transition of state values by skipping one state value, and the pattern of transition of state values by skipping two state values? If so, rotation can be detected. Therefore, in the rotary encoder according to the first embodiment, even when the optical sensor elements 5 and 6 are intermittently driven only by changing the signal processing with respect to the conventional configuration, the intermittent drive is compared with the conventional configuration. The constraint between the period and the measurable range can be relaxed.

That is, when the rotating shaft 10 rotates at a low speed, detection with high resolution and detection of the rotation direction are possible as in the conventional case. On the other hand, when the rotating shaft 10 rotates at a high speed, detection is performed with low resolution, and the direction of rotation cannot be detected (assuming the same direction as at low speed), but instead the upper limit of the number of rotations of the rotating shaft 10 or The upper limit of the intermittent drive cycle can be tripled.
Moreover, it becomes possible to reduce power consumption by making the period of intermittent drive longer than before.

  As described above, according to the first embodiment, a set of photosensor elements 5 and 6 that are arranged so as to be out of phase and that output signals in accordance with the displacement of an object by intermittent driving, and a set. The state value detection unit 701 that detects a state value indicating the presence / absence of signals from the optical sensor elements 5 and 6 and the transition of the state value detected by the state value detection unit 701 changes the detection mode to the low speed mode or the high speed mode. When the mode switching unit 702 for switching and the detection mode is the low speed mode, the rotation direction and the rotation amount of the rotary shaft 10 are detected from the transition of the state value detected by the state value detection unit 701, and the detection mode is the high speed mode. In some cases, it is assumed that the rotation direction of the rotation shaft 10 is the same as the rotation direction detected immediately before, and the displacement for detecting the rotation amount of the rotation shaft 10 from the transition of the state value detected by the state value detection unit 701 detection Since a 703, the optical sensor elements 5 and 6 even when intermittently driven, with respect to the conventional configuration, it is possible to relax the constraints between the measurable range and the cycle of the intermittent drive.

Embodiment 2. FIG.
In the first embodiment, the case where the detection mode is switched by performing the determination based on the transition of the state value is shown. However, if the speed of the rotating shaft 10 increases rapidly and fails to detect a point where the state value changes two before or after two, the detection mode is not switched to the high speed mode, and the measurement is erroneously performed. End up. On the other hand, it can be assumed that the rotation direction of the rotating shaft 10 does not change suddenly. Therefore, in the second embodiment, a method of switching to the high speed mode at an early stage when a certain level of speed can be detected before the state value transitions two times before or after two will be described.
FIG. 9 is a diagram showing a configuration example of the arithmetic unit 7 in the second embodiment of the present invention. In the calculation unit 7 in the second embodiment shown in FIG. 9, the mode switching unit 702 is changed to the mode switching unit 702b with respect to the calculation unit 7 in the first embodiment shown in FIG. Other configurations are the same, and the same reference numerals are given and description thereof is omitted.

  The mode switching unit 702b switches the detection mode in the displacement detection unit 703 to the low speed mode or the high speed mode from the transition of the state value detected by the state value detection unit 701. At this time, the mode switching unit 702 b first calculates the average speed of the rotating shaft 10 from the displacement amount of the rotating shaft 10 detected by the displacement detecting unit 703 and the detection period in the state value detecting unit 701. Then, when the detection mode is the low speed mode, the mode switching unit 702b switches the detection mode to the high speed mode when the average speed is equal to or greater than the threshold value. In addition, after switching the detection mode to the high speed mode, the mode switching unit 702b switches the detection mode to the low speed mode when the average speed is less than the threshold value for a certain period.

Next, the setting of the threshold value will be described.
Here, at every detection cycle by the state value detection unit 701, the speed at which transition to the previous (next) state value continues is changed to the previous (second) state value. Maximum speed (speed immediately before transition to the state value two previous (two subsequent)).

For example, FIG. 10A shows a signal waveform during forward rotation when the speed of the rotating shaft 10 is the same as the maximum speed. A solid line arrow indicates a detection timing by the state value detection unit 701. In this case, the state value detection unit 701 detects the previous state value every time.
On the other hand, FIG. 10B shows a signal waveform during forward rotation when the speed of the rotating shaft 10 is slightly slower than the maximum speed. In this case, the state value detection unit 701 detects the previous state value almost every time, but partially detects a state value without a transition. Note that the rate at which the state value detection unit 701 detects a state value without transition is proportional to the speed of the rotating shaft 10.
FIG. 10C shows a signal waveform during forward rotation when the speed of the rotating shaft 10 is slightly higher than the maximum speed. In this case, the state value detection unit 701 detects the previous state value almost every time, but partially detects the previous state value. The rate at which the state value detection unit 701 detects the previous state value is proportional to the speed of the rotating shaft 10.

  Here, the second embodiment aims to switch the detection mode to the high speed mode when the speed before the state value transitions two times before or after two is detected. For this reason, the threshold is set to an arbitrary speed equal to or lower than the maximum speed.

Thus, even if the detection mode is switched based on the average speed of the rotating shaft 10, the same effect as in the first embodiment can be obtained.
Also, if the state value is set to an arbitrary speed that is less than or equal to the maximum speed at which the state value does not change two times before or after two, the state value jumps (transitions two or two times later). You can switch to high-speed mode as soon as possible.

  In the above description, the case where the mode switching unit 702b performs determination based on the average speed for both the case where the detection mode is switched to the high speed mode and the case where the detection mode is switched to the low speed mode is shown. However, the present invention is not limited to this, and one of the switching to the high speed mode and the switching to the low speed mode may be performed by the state value transition described in the first embodiment.

In the first and second embodiments, an optical encoder is used as the rotary encoder. However, the present invention is not limited to this, and in the magnetic rotary encoder, the signal obtained by the magnetic sensor element (sensor element) is the same as the signal obtained by the optical sensor elements 5 and 6, and the first and second embodiments. The configuration can be similarly applied.
In the first and second embodiments, the case where the rotary encoder is mounted on a home or business meter such as a gas meter and a water meter has been described as an example. However, the present invention is not limited to this, and other rotary encoders are used. May be used.

  In the first and second embodiments, the case where the rotary encoder that detects the rotation of the rotating shaft 10 is used as the detection device that detects the displacement of the object has been described. However, the present invention is not limited to this, and a linear encoder that detects the movement (displacement) of an object such as a single-axis robot or a digital caliper may be used as the detection device, and the configurations of the first and second embodiments are the same. It is applicable to. Even when the configurations of the first and second embodiments are applied to the linear encoder, the moving direction cannot be determined when the object moves at a high speed (assuming the same direction as that at the low speed movement). . However, since it is physically difficult for the object to reverse the direction of movement without going through a low-speed movement state, it is considered that there are few applications in which this is a problem.

  In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

DESCRIPTION OF SYMBOLS 1 Light source 2 Lens 3 Rotating disk 4 Fixed slit 5, 6 Optical sensor element 7 Calculation part 10 Rotating shaft 701 State value detection part 702, 702b Mode switching part 703 Displacement detection part 301 Insertion hole 302 Slit 401, 402 Slit

Claims (6)

A set of sensor elements arranged so as to be out of phase and outputting signals in accordance with the displacement of the object by intermittent driving;
A state value detection unit for detecting a state value indicating presence / absence of a signal from a set of the sensor elements;
From the transition of the state value detected by the state value detection unit, a mode switching unit that switches the detection mode to the low speed mode or the high speed mode,
When the detection mode is the low speed mode, the displacement direction and the displacement amount of the object are detected from the transition of the state value detected by the state value detection unit, and when the detection mode is the high speed mode, A displacement detector that detects the amount of displacement of the object from the transition of the state value detected by the state value detector, assuming that the displacement direction of the object is the same as the displacement direction detected immediately before Detection device. The mode switching unit, when the detection mode is a low speed mode, when the state value detected by the state value detection unit transitions two previous or two after the state value detected immediately before In addition, the detection mode is switched to a high-speed mode. The mode switching unit calculates an average speed of the target object from a displacement amount of the target object detected by the displacement detection part and a detection cycle in the state value detection part, and when the detection mode is a low speed mode. The detection device according to claim 1, wherein the detection mode is switched to a high-speed mode when the average speed is equal to or higher than a threshold value. The mode switching unit switches the detection mode to the high-speed mode, and the state value detected by the state value detection unit for a certain period of time is immediately before or after the state value detected immediately before. The detection mode is switched to the low-speed mode when there is a transition or when there is no transition with respect to the state value detected immediately before. Any one of claims 1 to 3 The detection device described. The mode switching unit calculates an average speed of the target object from a displacement amount of the target object detected by the displacement detection unit and a detection period in the state value detection unit, and after switching the detection mode to a high speed mode. The detection device according to any one of claims 1 to 3, wherein the detection mode is switched to a low speed mode when the average speed is less than a threshold value for a certain period of time. It is a detection method by a detection device having a set of sensor elements that are arranged so as to be out of phase, are intermittently driven, and output signals according to the displacement of an object,
The state value detection unit detects a state value indicating the presence / absence of a signal from the one set of sensor elements,
The mode switching unit switches the detection mode to the low speed mode or the high speed mode from the transition of the state value detected by the state value detection unit,
When the detection mode is the low speed mode, the displacement detection unit detects the displacement direction and the displacement amount of the object from the transition of the state value detected by the state value detection unit, and the detection mode is the high speed mode. In some cases, assuming that the displacement direction of the object is the same as the displacement direction detected immediately before, the displacement amount of the object is detected from the transition of the state value detected by the state value detection unit. Feature detection method.

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