JP4755049B2 - Mirror control device and mirror control method - Google Patents

Description

  The present invention relates to a mirror control device that tilts a mirror that is rotatably supported at a predetermined angle.

  As one technique for realizing an optical switch, a technique using a deflecting element such as a micromirror has been proposed (see, for example, Non-Patent Document 1). A conventional optical switch using a micromirror is shown in FIG.

  The optical switch shown in FIG. 5 includes an input port 1a, an output port 1b, an input side micromirror array 2a, and an output side micromirror array 2b. The input port 1a and the output port 1b are each composed of a plurality of optical fibers arranged two-dimensionally, and the micromirror arrays 2a and 2b are each composed of a plurality of micromirror devices 3a and 3b arranged two-dimensionally. . In addition, the arrow in FIG. 5 has shown the advancing direction of the light beam.

  An optical signal emitted from a certain input port 1a is reflected by the mirror of the micromirror device 3a of the input side micromirror array 2a corresponding to this input port 1a, and its traveling direction is changed. As will be described later, the mirror of the micromirror device 3a is configured to be rotatable about two axes, and the reflected light of the micromirror device 3a can be directed to any micromirror device 3b of the output side micromirror array 2b. it can. Similarly, the mirror of the micromirror device 3b is also configured to be rotatable about two axes, and the reflected light of the micromirror device 3b is directed to an arbitrary output port 1b by appropriately controlling the tilt angle of the mirror. be able to. Therefore, by appropriately controlling the tilt angles of the mirrors of the input-side micromirror array 2a and the output-side micromirror array 2b, the optical path is switched, and the arbitrary input port 1a and output port 1b arranged two-dimensionally Can be connected.

  The most characteristic components of such an optical switch are micromirror devices 3a and 3b having mirrors. Conventionally, as shown in FIGS. 6 and 7, the micromirror device has a structure in which a mirror substrate 200 on which a mirror is formed and an electrode substrate 300 on which an electrode is formed are arranged in parallel (for example, (Refer nonpatent literature 1.).

  The mirror substrate 200 includes a plate-shaped frame portion 210, a movable frame 220 disposed in the opening of the frame portion 210, and a mirror 230 disposed in the opening of the movable frame 220. The frame part 210, the torsion springs 211a, 211b, 221a, 221b, the movable frame 220 and the mirror 230 are integrally formed of, for example, single crystal silicon. For example, three Ti / Pt / Au layers are formed on the surface of the mirror 230. The pair of torsion springs 211 a and 211 b connect the frame part 210 and the movable frame 220. The movable frame 220 can rotate about the movable frame rotation axis X of FIG. 6 passing through the pair of torsion springs 211a and 211b. Similarly, the pair of torsion springs 221 a and 221 b connect the movable frame 220. The mirror 230 can rotate about the mirror rotation axis Y of FIG. 6 passing through the pair of torsion springs 221a and 221b. The movable frame rotation axis X and the mirror rotation axis Y are orthogonal to each other. As a result, the mirror 230 rotates about two orthogonal axes.

  The electrode substrate 300 has a plate-like base portion 310 and a terrace-like protruding portion 320. The base 310 and the protrusion 320 are made of, for example, single crystal silicon. The protrusion 320 includes a second terrace 322 having a truncated pyramid shape formed on the upper surface of the base 310, a first terrace 321 having a truncated pyramid shape formed on the upper surface of the second terrace 322, and the first terrace. And a pivot 330 having a columnar shape formed on the upper surface of 321. Four electrodes 340 a to 340 d are formed on the four corners of the protruding portion 320 and the upper surface of the base portion 310 following the four corners. In addition, a pair of convex portions 360 a and 360 b are provided on the upper surface of the base portion 310 so as to sandwich the protruding portion 320. Further, a wiring 370 is formed on the upper surface of the base 310, and electrodes 340a to 340d are connected to the wiring 370 via lead lines 341a to 341d. An insulating layer 311 made of silicon oxide or the like is formed on the surface of the base 310, and electrodes 340a to 340d, lead lines 341a to 341d, and wirings 370 are formed on the insulating layer 311.

  The mirror substrate 200 and the electrode substrate 300 as described above are formed by joining the lower surface of the frame portion 210 and the upper surfaces of the convex portions 360a and 360b so that the mirror 230 and the electrodes 340a to 340d are opposed to each other. A micromirror device as shown in FIG. 7 is configured. In such a micromirror device, the mirror 230 is grounded, a positive driving voltage is applied to the electrodes 340a to 340d, and an asymmetric potential difference is generated between the electrodes 340a to 340d, thereby causing the electrostatic attraction force of the mirror 230. And the mirror 230 can be rotated in an arbitrary direction.

T. Yamamoto, et al., `` A three-dimensional MEMS optical switching module having 100 input and 100 output ports '', Photonics Technology Letters, IEEE, Volume 15, Issue: 10, pp1360-1362

  In the micromirror device as described above, when a voltage is applied to the electrodes 340a to 340d, the electrodes, the insulator 311 around the electrodes, and the like may be polarized or charged. If this is gradually discharged or charged, the potential between the mirror 230 and the electrodes 340a to 340d varies with time, and the tilt angle of the mirror 230 varies with time, that is, drift occurs. there were.

For example, as shown in FIG. 8, when the relationship between the tilt angle of the mirror 230 and the drive voltage of the electrodes 340a to 340d shifts from the state of the curve a to the state of the curve b due to drift, the same drive voltage Even if V ₁ is applied, the tilt angle increases by Δθ after drift.

  When the change in the mirror angle characteristic occurs in this way, the tilt angle of the mirror 230 changes even when the same voltage is applied, so that the loss of output light increases or the mirror 230 cannot be driven to a desired angle. End up.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a mirror control device and a mirror control method that can appropriately control the tilt angle of a mirror by eliminating the influence of drift.

In order to solve the above-described problems, a mirror control device according to the present invention applies a predetermined drive voltage to a plurality of electrodes arranged to face a mirror that is rotatably supported to rotate the mirror. In a mirror control device for controlling an angle, a drive voltage applied to a plurality of electrodes is periodically changed for each electrode, and a plurality of perturbation voltage supply units for perturbing the mirror and a plurality of rotations based on a change in the rotation angle of the perturbed mirror And a drive voltage correction unit that corrects the drive voltage applied to each of the electrodes and maintains the rotation angle of the mirror at a predetermined level. The drive voltage correction unit is driven at a constant magnitude by the perturbation unit. A correction voltage calculation unit that obtains a correction voltage that makes the amplitude of the rotation angle of the mirror constant when the angle is periodically changed, and a drive voltage update unit that corrects the drive voltage with the correction voltage to obtain a new drive voltage; Characterized by having To.

  In the mirror control device, the perturbation voltage supply unit may change the drive voltage sinusoidally.

Further, in the mirror controller, perturbation voltage supply unit, or gives the amplitude of the individual voltage driving voltage for every electrode applied to the plurality of electrodes, each electrode in the drive voltage applied to the plurality of electrodes You may make it change by shifting time.

  In the mirror control device, the drive voltage correction unit may correct the drive voltage based on the power of light deflected by the mirror and output from a predetermined output port.

  In the mirror control device, the drive voltage correction unit may correct the drive voltage for each of a plurality of different rotation angles of the mirror.

Further, a mirror control method according to the present invention is a mirror control method for controlling a rotation angle of a mirror by applying a predetermined driving voltage to a plurality of electrodes arranged to face a mirror that is rotatably supported. A drive voltage to be applied to the plurality of electrodes is periodically changed for each electrode, and a perturbation voltage supply step for perturbing the mirror and a drive voltage to be applied to each of the plurality of electrodes based on a change in the rotation angle of the mirror to be perturbed. And a drive voltage correction step that corrects and maintains the rotation angle of the mirror at a predetermined magnitude, and the drive voltage correction step periodically changes the drive voltage at a constant magnitude by the perturbation voltage supply step . Sometimes there is a correction voltage calculation step for obtaining a correction voltage for making the amplitude of the mirror rotation angle constant, and a drive voltage update step for correcting the drive voltage with the correction voltage to obtain a new drive voltage. And wherein the Rukoto.

  According to the present invention, by correcting the drive voltage applied to the electrode based on the change in the rotation angle of the perturbed mirror, the effect of drift can be eliminated and the rotation angle of the mirror can be controlled appropriately. it can.

  Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, components equivalent to those described in the background art section with reference to FIGS. 5 to 7 are denoted by the same names and reference numerals, and description thereof is omitted as appropriate.

[Configuration of optical switch]
As shown in FIG. 1, the optical switch 10 according to the present embodiment includes an input port 1a, an output port 1b, an input side micromirror device 3a, an output side micromirror device 3b, and an output light measurement device 4. And a control device 5.

  The output light measuring device 4 detects the intensity of the output light emitted from the output port 1b and converts it into an electrical signal. As a configuration example of such an output light measuring device 4, a configuration in which a part of the output light is cut out and the intensity of the output light is measured by a light receiving element such as a photodiode can be considered.

  The control device 5 includes a drive unit 6, a detection unit 7, a drive voltage correction unit 8, and a storage unit 9.

  The drive unit 6 supplies a drive voltage to the micromirror devices 3a and 3b to tilt the mirror 230 at a predetermined angle, or perturbs (vibrates) the mirror 230 by giving a minute change to the drive voltage. Such a drive unit 6 includes a drive voltage supply unit 61 and a perturbation voltage supply unit 62.

  The drive voltage supply unit 61 generates a drive voltage to be applied to the electrodes 340a to 340d in order to tilt the mirror 230 of the micromirror devices 3a and 3b at a predetermined angle based on an instruction from the outside, and the like. To ~ 340d. Here, the drive voltage is generated with reference to the storage unit 9.

  The perturbation voltage supply unit 62 applies a drive voltage (hereinafter referred to as “perturbation voltage”) to the electrodes 340 a to 340 d to perturb the mirror 230 of the micromirror devices 3 a and 3 b based on an instruction from the drive voltage correction unit 8. Is supplied to the electrodes 340a to 340d. The perturbation voltage is composed of a periodically changing voltage such as a sine wave or a triangular wave, for example, and is generated by setting the amplitude and the period according to the drive voltage based on the value stored in the storage unit 9.

  The detection unit 7 detects the measurement result of the output light by the output light measurement device 4 when the driving unit 6 drives the micromirror devices 3a and 3b. The detected value is output to the drive voltage correction unit 8.

  The drive voltage correction unit 8 is a functional unit that corrects the drive voltage supplied by the drive unit 6 in order to eliminate the influence of drift. Such a drive voltage correction unit 8 includes an instruction unit 81, a correction voltage calculation unit 82, and an update unit 83.

  The instruction unit 81 supplies a drive voltage to the electrodes 340a to 340d of the micromirror devices 3a and 3b that perform drift correction by the drive voltage supply unit 61 and a perturbation voltage from the perturbation voltage supply unit 62. The mirror 230 is perturbed.

  The correction voltage calculation unit 82 detects the amount of change in the tilt angle of the mirror 230 due to drift from the measurement result by the output light measurement device 4 when the mirror 230 is perturbed based on the instruction from the instruction unit 81, and the detection result The charge accumulated in the electrode and the insulator around the electrode is estimated, and a voltage (hereinafter referred to as “correction voltage”) applied to the electrodes 340a to 340d in order to cancel the charge is calculated. Such a correction voltage calculation unit 82 detects the displacement of the rotation angle of the mirror 230 based on the measurement result of the output light measurement device 4 detected by the detection unit 7, that is, the change in the intensity of the output light. 82a, a conversion part 82b for converting the rotation angle of the mirror 230 detected by the rotation angle detection part 82a into a voltage value, and a rotation angle of the mirror 230 detected by the rotation angle detection part 82a A calculating unit 82c that calculates a correction voltage based on the voltage value corresponding to the rotation angle converted by the unit 82b.

  The update unit 83 instructs the drive voltage supply unit 61 to supply the correction voltage calculated by the correction voltage calculation unit 82 to the electrodes 340a to 340d.

  The storage unit 9 stores a drive voltage supplied by the drive voltage supply unit 61, a perturbation voltage referred to by the perturbation voltage supply unit 62, a program for realizing the operation of the optical switch 10, and the like. Here, the driving voltage is a combination of the micromirror device 3a and the micromirror device 3b for forming an optical path for emitting an optical signal emitted from any one input port 1a from any one output port 1b ( Hereinafter, it may be stored in the form of a table for each “connection path”.

  Such a control device 5 includes an arithmetic device such as a CPU, a storage device such as a memory and an HDD (Hard Disc Drive), an input device that detects input of information from the outside such as a keyboard, a mouse, a pointing device, a button, and a touch panel, I / F devices that send and receive various types of information via communication lines such as the Internet, LAN (Local Area Network), WAN (Wide Area Network), etc., and CRT (Cathode Ray Tube), LCD (Liquid Crystal Display) or FED The computer includes a display device such as (Field Emission Display) and a program installed in the computer. That is, the hardware device and software cooperate to control the above hardware resources by a program, and the above-described drive unit 6, detection unit 7, drive voltage correction unit 8, and storage unit 9 are realized. Note that the program may be provided in a state of being recorded on a recording medium such as a flexible disk, a CD-ROM, a DVD-ROM, or a memory card.

[Correction]
Next, the drift correction operation by the drive voltage correction unit 8 will be described.

(Operating principle)
As described above, the drift is considered to be one of the causes of the accumulation of electric charges in the electrode and the insulator around the electrode. When this accumulated charge is converted into an applied voltage to the electrode, the state in which the drift has occurred can be regarded as a state in which a voltage due to the charge is applied to the drive voltage. For example, as shown in FIG. 2, when the relationship between the tilt angle of the mirror 230 and the drive voltage of one of the electrodes 340 a to 340 d shifts from the state of the curve a to the state of the curve b due to the occurrence of drift, The state of the curve b can be regarded as a state where a predetermined voltage (hereinafter referred to as “drift voltage”) α is applied to the state of the curve a. Therefore, in the present embodiment, by applying a correction voltage that cancels out the drift voltage α to the corresponding electrode, the influence of the drift is eliminated, and the tilt angle of the mirror is appropriately controlled.

(Operation by instruction unit)
First, when the driving of the micromirror devices 3a and 3b is started, a predetermined time has elapsed since the driving, the power loss of the output light exceeds a predetermined value, or the connection path is changed, the driving voltage The instruction unit 81 of the correction unit 8 instructs the drive voltage supply unit 61 and the perturbation voltage supply unit 62 to supply the perturbation voltage together with the drive voltage. The start of driving the micromirror devices 3a and 3b, the elapse of a predetermined time from the start of driving, the change of the connection path, and the like are detected by monitoring the operation of the drive voltage supply unit 61. Further, the power loss of the output light is detected from the measurement result of the output light measurement device 4 obtained via the detection unit 7.

  It is not always necessary to apply the perturbation voltage. For example, it may be performed immediately after switching the connection path, or may be performed at regular intervals thereafter.

(Operation by correction voltage calculator)
When the perturbation voltage is supplied according to an instruction from the instruction unit 81, the calculation unit 82c of the correction voltage calculation unit 82 accumulates in the electrodes 360a to 360d and the insulator around the electrode based on the swing width of the mirror 230. The charge is estimated, and the drift voltage corresponding to this charge is estimated.

When perturbation is performed after the occurrence of drift, the swing width of the mirror 230 at this time becomes larger than that before the drift. For example, as shown in FIG. 2, when a perturbation voltage that periodically changes in the voltage V _{2 to} V ₃ range is applied in a state where the drive voltage V ₁ is applied to the electrodes 340 a to 340 d, the shake of the mirror 230 after the drift occurs. The width Δθ ₂ is larger than the swing width Δθ ₁ of the mirror 230 before drift. In this way, paying attention to the fact that when the mirror 230 is perturbed in a state where drift has occurred, the fluctuation width becomes larger than when no drift has occurred, and the perturbation voltage is applied to the electrodes 340a to 340d together with the drive voltage. Then, the mirror 230 is perturbed, and the drift voltage is calculated based on the swing width at this time. There are two calculation methods. Each will be described below.

<First calculation method>
The first calculation method pays attention to the DC component of the tilt angle of the mirror 230, and calculates the drift voltage from the amount of change of the DC component. For example, as shown in FIG. 3A, when drift occurs while the mirror 230 is tilted with respect to the electrodes 340a to 340d, the tilt angle when the mirror 230 is perturbed is shown in FIG. As shown, the DC component, that is, the average value of the rotation angle of the mirror 230 changes with time. In other words, the rotation angle when the mirror 230 is perturbed changes while maintaining the magnitude of the amplitude. Therefore, the calculation unit 82c of the correction voltage calculation unit 82 calculates the drift voltage from the change amount of the DC component.

  When the angle increases, the calculation unit 82c indicates that the drift voltage has increased since it indicates that the drift voltage α has the same polarity as the drive voltage. On the other hand, when the angle decreases, the calculation unit 82c estimates that the drift voltage has decreased. Thereby, even if the mirror 230 is tilted, the drift voltage can be accurately calculated.

  The value of the drift voltage is calculated by converting the amount of change in the tilt angle of the mirror 230 due to drift into a voltage by the converter 82b. Specifically, it is calculated based on the angle of the mirror 230 when the perturbation voltage is applied and the value of the perturbation voltage. As described above, the angle of the mirror 230 is detected by the rotation angle detection unit 82a based on the measurement result of the output light measurement device 4 by the detection unit 7, that is, the intensity change of the output light.

<Second calculation method>
The second calculation method focuses on the amplitude of the tilt angle of the mirror 230 and calculates the drift voltage from this amplitude. For example, as shown in FIG. 4A, when drift occurs when the mirror 230 is horizontal with respect to the electrodes 340a to 340d, the tilt angle when the mirror 230 is perturbed is shown in FIG. Thus, the amplitude increases with the passage of time. Therefore, the calculation unit 82c of the correction voltage calculation unit 82 calculates the drift voltage from the amount of change in amplitude.

  When the amplitude increases, the slope of the voltage-angle characteristic increases, indicating that the drift voltage α has the same polarity as the drive voltage, so it is estimated that the drift voltage has increased. On the other hand, when the amplitude decreases, the calculation unit 82c estimates that the drift voltage has decreased. Thereby, even when the mirror 230 is horizontal, the drift voltage can be accurately calculated.

  As in the case of the first estimation method, the value of the drift voltage is estimated by converting the angle change of the mirror 230 into a voltage.

  Here, any voltage can be used as the perturbation voltage supplied from the perturbation voltage supply unit 62 in order to calculate the drift voltage, but a periodically changing voltage such as a sine wave or a triangular wave is used. In this case, the correlation between the angle of the mirror 230 and the perturbation voltage, or the frequency of the angle of the mirror 230 is analyzed by FFT (Fast Fourier Transform) or the like, and the direct current component and the periodic component are extracted. Components and amplitudes can be estimated more easily.

  In addition, the amplitude of the perturbation voltage can be set as appropriate as long as the increase in amplitude due to drift can be detected. Further, the period of perturbation can be set freely as long as it is within a range in which the mirror 230 can respond.

  Note that the first and second calculation methods described above may be used in combination such as switching from the tilt angle of the mirror 230. For example, as shown in FIG. 3A, when the mirror 230 is tilted, the effect of drift caused by the periphery of the electrode nearer to the pair of mirrors 230 is applied to the electrode far from the mirror 230. The drift voltage cannot be accurately calculated by the first calculation method. In such a case, the drift voltage is calculated by the second calculation method for the electrode far from the mirror 230. At this time, the drift voltage is calculated by the first calculation method for the electrode located near the mirror 230. By doing so, the drift voltage can be calculated more accurately.

  When the drift voltage is calculated by the method as described above, the calculation unit 82c generates a correction voltage that cancels out the drift voltage based on the calculated drift voltage. For example, a voltage having the same absolute value as that of the drift voltage and having the opposite sign is generated as a correction voltage, and the drift voltage is added to the detected drive voltage. The drive voltage to which the correction voltage is added is supplied to the corresponding electrodes 360a to 360d by the drive voltage supply unit 61. Thereby, since the corrected drive voltage is supplied to the electrodes 340a to 340d, it becomes possible to eliminate the influence of drift, and as a result, the rotation angle of the mirror 230 can be appropriately controlled.

  As described above, according to the present embodiment, based on the tilt angle of the mirror 230 when the drive voltage and the perturbation voltage are supplied to the electrodes 360a to 360d by the drive voltage supply unit 61 and the perturbation voltage supply unit 62. The drift voltage corresponding to the amount of change in the tilt angle of the mirror 230 due to the drift is calculated, and the drive voltage is corrected based on this drift voltage, so that the influence of the drift is eliminated and the tilt angle of the mirror is appropriately controlled. be able to.

  In this embodiment, the correction voltage is supplied so as to keep the tilt angle of the mirror 230 constant. However, the correction voltage is also used when the mirror 230 is driven at a different angle when the connection path is switched. It may be. That is, at the time of switching the connection path, it may be assumed that the correction voltage applied immediately before is already applied to the electrodes, and the correction voltage may be subtracted from the drive voltage when no drift has occurred. Thereby, the mirror 230 can be driven with high accuracy.

  In the case of the mirror 230 driven by a plurality of electrodes as in this embodiment, the drift voltage may be estimated for each electrode. In this case, the drift voltage of each electrode can be estimated by applying individual signals such as changing the frequency of the perturbation voltage for each electrode. Moreover, the drift voltage of each electrode can be estimated by applying the same perturbation voltage while shifting the time. By supplying a correction voltage to each electrode based on the drift voltage estimated in this way, the influence of drift can be more effectively eliminated and the tilt angle of the mirror 230 can be controlled more appropriately. Further, the drift voltage may be generated not only for one angle of the mirror 230 but also for each of a plurality of angles.

  In this embodiment, the case where the present invention is applied to an optical switch has been described as an example. However, a deflection element such as a mirror is tilted by applying a voltage to an electrode disposed opposite to the deflection element. If it is an apparatus to be made, it can be applied to various apparatuses.

  The present invention can be applied to various devices such as a micromirror device that tilts a deflection element by applying a voltage to an electrode disposed opposite to the deflection element.

(A) is a block diagram showing the configuration of the optical switch of the present invention, (b) is a block diagram showing the configuration of the control device. It is a figure which shows typically the relationship between the tilt angle of the mirror by a drift, and a drive voltage. (A) is a figure which shows typically the state which the mirror inclined, (b) is a figure which shows typically the time-dependent change of the tilt angle of a mirror when a drift generate | occur | produces in (a). (A) is a figure which shows typically a mirror horizontal state, (b) is a figure which shows typically the time-dependent change of the tilt angle of a mirror when a drift generate | occur | produces in (a). It is a perspective view which shows the structure of an optical switch typically. It is a perspective view which shows the structure of a mirror apparatus typically. It is sectional drawing which shows the structure of a mirror apparatus typically. It is a figure which shows typically the relationship between the tilt angle of the mirror by a drift, and a drive voltage.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1a ... Input port, 1b ... Output port, 3a ... Input side micromirror device, 3b ... Output side micromirror device, 4 ... Output light measuring device, 5 ... Control device, 6 ... Drive part, 7 ... Detection part, 8 ... Drive voltage correction unit, 9 ... storage unit, 10 ... optical switch, 61 ... drive voltage supply unit, 62 ... perturbation voltage supply unit, 81 ... instruction unit, 82 ... correction voltage calculation unit, 82a ... rotation angle detection unit, 82b ... Conversion unit, 82c ... Calculation unit, 83 ... Update unit.

Claims (7)

In a mirror control device for controlling a rotation angle of the mirror by applying a predetermined drive voltage to a plurality of electrodes arranged opposite to the mirror supported rotatably.
The drive voltage applied to the plurality of electrodes periodically changed for each of the electrodes, and the perturbation voltage supply unit to perturb the mirror,
A drive voltage correction unit that corrects the drive voltage applied to each of the plurality of electrodes based on a change in the rotation angle of the mirror to be perturbed, and maintains the rotation angle of the mirror at a predetermined size. ,
The drive voltage correction unit
A correction voltage calculation unit for obtaining a correction voltage for making the amplitude of the rotation angle of the mirror constant when the drive voltage is periodically changed with a constant magnitude by the perturbation voltage supply unit;
And a drive voltage update unit that corrects the drive voltage with the correction voltage to obtain a new drive voltage. In the mirror control device according to claim 1,
The perturbation voltage supply unit includes:
The mirror control device characterized in that the drive voltage is changed sinusoidally. The mirror control device according to claim 1 , wherein
The perturbation voltage supply unit includes:
A mirror control device, wherein the drive voltage applied to each of the plurality of electrodes is individually given an amplitude for each of the electrodes. The mirror control device according to claim 1 , wherein
The perturbation voltage supply unit includes:
Mirror control device according to claim the drive voltage applied to each of the plurality of electrodes changing at different times for each of the electrodes. The mirror control device according to any one of claims 1 to 4 ,
The drive voltage correction unit
The mirror control device, wherein the drive voltage is corrected based on the power of light deflected by the mirror and output from a predetermined output port. In the mirror control device according to any one of claims 1 to 5 ,
The drive voltage correction unit corrects the drive voltage for each of a plurality of different rotation angles of the mirror. In a mirror control method for controlling a rotation angle of the mirror by applying a predetermined driving voltage to a plurality of electrodes arranged to face a mirror that is rotatably supported.
A perturbation voltage supply step of perturbing the mirror by periodically changing the drive voltage applied to the plurality of electrodes for each electrode ;
A drive voltage correction step of correcting the drive voltage applied to each of the plurality of electrodes based on a change in the rotation angle of the mirror to be perturbed, and maintaining the rotation angle of the mirror at a predetermined magnitude. ,
The drive voltage correction step includes
A correction voltage calculation step for obtaining a correction voltage for making the amplitude of the rotation angle of the mirror constant when the drive voltage is periodically changed at a constant magnitude by the perturbation voltage supply step ;
And a drive voltage update step of correcting the drive voltage with the correction voltage to obtain a new drive voltage.

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