JP2007017769A - Micro thin film movable element for optical communication, and micro thin film movable element array - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a micro thin film movable element and a micro thin film movable element array for optical communication, capable of reducing the vibration of a movable part in an active way, and speed up switching operation. <P>SOLUTION: The micro thin film movable element 100 for optical communication comprises a movable part 27, where the part 27 is supported elastically displaceably and is capable of being displaced bi-directionally, and which has a switching function. The element has a plurality of drive sources for applying a physical acting force to the movable part 27. When the movable part 27 is driven displaceably in a first direction by the drive source and while the movable part 27 is being transition driven in the first direction, physical acting force for restraining the vibration of the movable part is applied with respect to the movable part 27 by the drive source, in a second direction that is different from the first direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a small thin film movable element for optical communication and a small thin film movable element array having a movable part that is displaced in both directions, and more particularly to an improved technique for actively reducing vibration of the movable part.

  2. Description of the Related Art In recent years, with the rapid advancement of MEMS technology (MEMS: Micro-Electro Mechanical Systems), development of micro electromechanical elements that electrically displace and move micro structures on the order of μm has been actively performed. Examples of the microelectromechanical element include a digital micromirror device (DMD) that deflects light by tilting a micromirror, and an optical switch as a small thin film movable element that switches an optical path. DMD is widely used in the field of optical information processing, such as projection displays, video monitors, graphic monitors, televisions, and electrophotographic prints. Further, the optical switch is expected to be applied to optical communication, optical interconnection (signal connection technology using light such as an interconnection network in a parallel computer), optical information processing (information processing using optical calculation), and the like.

  A microelectromechanical element generally includes a movable part that is supported so as to be elastically displaceable and can be displaced in one or both directions, and this movable part mainly performs a switching operation. Therefore, the braking control of the movable part is particularly important for good switching operation.

  For example, a micromirror device disclosed in Patent Document 1 below applies a voltage to one electrode of a pair of drive electrodes, and a movable part having a mirror disposed by hinge connection between these electrodes is defined as a drive electrode. It is made into the structure rotated by the electrostatic attraction according to the electric potential difference and electrostatic capacitance between.

The optical path switching device disclosed in Patent Document 2 includes a mechanical optical switch that switches a light path by applying a signal voltage to an electromagnetically driven actuator, and a control circuit that supplies the signal voltage to the optical switch. The signal voltage is 2/3 V _H or less with respect to the signal rising amplitude V _H and the signal width T when T / 2 has elapsed from the signal rising. In the signal voltage applied to the actuator, when T / 2 has elapsed from the rise of the signal of the vibration width T, the signal voltage is reduced to 2/3 times or less of the rise amplitude to suppress vibration.

  Also, the optical switch switching control method disclosed in Patent Document 5 below is a vibration member that is displaced by turning on or off the control voltage, and the propagation light is reflected or blocked by the displacement of the vibration member at the tip of the vibration member. In the optical switch including the element to be applied, the first preliminary voltage pulse shorter than the natural vibration period of the vibrating member is applied to the vibrating member before the control voltage is turned on, and the vibrating member is turned off after the control voltage is turned off. A second preliminary voltage pulse shorter than the natural vibration period is applied to the vibrating member.

  Generally, in an optical switch, a phenomenon called chattering occurs when a vibration member is displaced by turning on and off a control voltage. This chattering does not immediately change the amount of displacement corresponding to the control voltage after the control voltage is turned on or off. This is a phenomenon of displacement by the amount. Therefore, until the vibration is attenuated and the light output reaches a certain level, the optical path is not switched, and the switching speed of the optical switch is limited. On the other hand, in the switching control method of the optical switch according to the conventional example, chattering is performed by applying a preliminary voltage pulse shorter than the natural vibration period of the vibrating member to the vibrating member before and after turning on the control voltage. It is controlled to improve the switching speed of the optical switch.

JP-A-8-334709 JP 2002-169109 A JP-A-2-7014

  However, in the micromirror device disclosed in Patent Document 1, a voltage is applied to one of the drive electrodes to generate an electrostatic attraction according to the potential difference and capacitance between the movable part and the drive electrode, Rotate the moving part. For this reason, as shown in FIG. 21A, vibration is generated by receiving a reaction force from the contact member immediately after the micromirror transits to the contact position by application of the voltage Va and lands on the contact position. Further, even in the case of a non-contact structure in which the micromirror does not land at the contact position, as shown in FIG. 21 (b), the overshoot occurs beyond the desired rotation angle (convergence position), thereby causing vibration. It took time to calm down. These vibrations and overshoots have hindered speeding up the switching operation of the microelectromechanical element.

Further, the optical path switching device disclosed in Patent Document 2 reduces the attractive force due to the coil magnetic field when the movable part approaches the tip of the yoke, that is, when the attractive force due to the permanent magnet magnetic field becomes strong in an electromagnetically driven actuator. The movable part is moved to the fiber connection position so that the total suction force does not become too strong. As shown in FIG. 22A, the waveform output by the signal generating circuit is a signal voltage that rapidly decreases after rising at a rising voltage V _H = 7V. The signal width T is 5 ms, and the signal termination voltage is 0.5V. The voltage after lapse of T / 2 from the rising edge is 2.8v. In FIG. 22B, the rising voltage is 7 V, the signal width T is 5 ms, and the time T _O = 1.5 ms when the amplitude changes stepwise. In FIG. 22C, the rising voltage is 5 V, and the time T until the reduced amplitude becomes 1 V is 2 ms. Time T corresponds to the signal width. After time T, the voltage of 1V is continuously applied until the next switching is performed. FIG. 22D shows a waveform in which the amplitude decreases stepwise to a constant value of 0.5 V at a rising voltage of 5 V and the time T _O = 3 ms until the stepped amplitude changes. These signal voltages increase the rising amplitude to speed up the movement (switching speed) of the movable part, and when the movable part begins to move, the signal voltage is sharply reduced to reduce the force applied to the movable part. Could be suppressed. However, this optical path switching device displaces the block that is the movable part in both directions in parallel, but it is trying to suppress vibration by changing the driving force acting in the forward direction, so the diversity of vibration control methods is poor. There was a disadvantage. In addition, basically the attraction force by the coil magnetic field is reduced and the signal voltage is reduced so that the total attraction force does not become too strong, and as described above, the vibration cannot be actively reduced.

  Further, as shown in FIG. 23, the optical switch switching control method disclosed in Patent Document 3 is configured to apply a first preliminary voltage pulse and a second preliminary voltage pulse to a vibrating member before turning on and off the control voltage. The electrostatic force works in one direction by one movable part electrode and one fixed electrode, and tries to suppress the vibration at the time of driving the movable part by balancing the elastic force and inertial force of the movable support part. However, since the electrostatic force (potential difference) only in the forward direction acting in the moving part transition direction is changed, there is a problem that the vibration suppressing effect is small. In general, an optical switch for optical communication is positioned at an arbitrary angle unlike DMD, so it takes a very long time to converge free vibration. Also, since optical information such as laser light is reflected and incident on the outgoing fiber, high control accuracy is required, but vibration of the movable part (mirror part) causes noise as the chattering described above. Thus, particularly in the case of an optical switch, the influence of vibration is larger than that of DMD, which is a serious problem.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and a small thin film movable element for optical communication and a small thin film capable of actively reducing the vibration of the movable part by exerting a physical attractive force in the direction opposite to the transition direction of the movable part. An object of the present invention is to provide a movable element array, thereby reducing chattering to reduce noise and speeding up a switching operation.

  In order to achieve the above object, a small thin film movable element for optical communication according to claim 1 according to the present invention is provided with a movable part supported so as to be elastically displaceable and bi-directionally displaced, and the movable part has a switching function. A small thin film movable element for communication, having a plurality of drive sources for applying a physical acting force to the movable part, and when the movable part is driven to be displaced in the first direction by the drive source, During the transition to the first direction, the driving source applies a physical acting force that suppresses vibration of the movable part in a second direction different from the first direction with respect to the movable part. Features.

  In this small thin film movable element for optical communication, during the transition before the movable part reaches the final displacement position, a physical attractive force acts in the direction opposite to the transition direction, and the movable part reaches the final displacement position. The previous speed is reduced. As a result, overshoot when reaching the final displacement position in the conventional non-contact drive and vibration due to the collision that occurs when the movable part in the contact drive reaches the final displacement position at a high speed are suppressed. That is, vibration at the time of contact of the movable part can be actively reduced.

  The small thin film movable element for optical communication according to claim 2, wherein after the movable part is driven to be displaced in the first direction, the movable source is moved by the drive source during the transition in the second direction. A physical acting force is applied to the movable part in the first direction.

  In this optical thin film movable element for optical communication, the movable portion is driven to move in the first direction, and after reaching the final position of the displacement, the second force is applied by the reaction force or the elastic force caused by contacting the stop member. During the transition to the direction, the physical acting force in the first direction is applied to the movable part, so that the movement of the movable part attempting to move away from the final position of the displacement is actively braked.

  The thin film movable element for optical communication according to claim 3 is characterized in that the physical action force is applied to a plurality of action points of the movable part.

  In this small thin film movable element for optical communication, since there are a plurality of action points, for example, in a swing type movable part whose center is the rotation center, physical acting force is applied to both sides sandwiching the rotation center. . As a result, braking forces of different magnitudes can be applied to the respective action points at different timings, and various braking effects can be obtained.

  The thin film movable element for optical communication according to claim 4 is characterized in that when the movable part reaches the final position of displacement in a specific direction, the speed of the movable part becomes substantially zero.

  In this small thin film movable element for optical communication, the speed at the moment when the movable part arrives at the final displacement position becomes substantially zero, and the overshoot at the time of reaching the final displacement position in the case of conventional non-contact drive or the movable part is large. The vibration caused by the collision caused by reaching the final displacement position at the speed is not generated.

  6. The small thin film movable element for optical communication according to claim 5, wherein the physical acting force that displaces the movable part in the first direction and the second direction by the driving source is an electrostatic force. To do.

  In this small thin film movable element for optical communication, a high-speed vibration suppression force can be obtained because the physical acting force that displaces the movable portion becomes an electrostatic force.

  The thin film movable element for optical communication according to claim 6 is characterized in that the physical acting force is applied in a pulse waveform with the intensity on the vertical axis and the time on the horizontal axis.

  In this small thin film movable element for optical communication, a physical acting force is generated in a voltage range specified by a pulse waveform, and various braking effects can be obtained. Here, the pulse waveform includes a rectangular wave, a sine wave, a cosine wave, a sawtooth wave, a triangular wave, and a synthesized wave thereof.

  The thin film movable element for optical communication according to claim 7 is characterized in that the physical acting force is generated by a plurality of pulse waveforms.

  In this optical thin film movable element for optical communication, physical acting force is applied at different magnitudes and at different timings, and various braking effects can be obtained.

  A thin thin film movable element array according to an eighth aspect is characterized in that the small thin film movable elements for optical communication according to any one of the first to seventh aspects are arranged one-dimensionally or two-dimensionally.

  In this small thin film movable element array, the small thin film movable element for optical communication that can perform high-speed switching operation is arrayed, and it is possible to shorten the time to calm down the vibration and write address voltage faster than before. It becomes.

  10. The small thin film movable element array according to claim 9, wherein each of the small thin film movable elements for optical communication has a drive circuit including a memory circuit, and the movable part and at least two fixed parts facing the movable part. One of the electrodes provided in the unit is a signal electrode to which an element displacement signal from the drive circuit is input, and the other is a common electrode.

  In this small thin film movable element array, a memory circuit is provided, so that an element displacement signal can be written in advance to the memory circuit. A constant common voltage as in the conventional case is applied to the common electrode, and at the same time, an element displacement signal previously written in the memory circuit is applied to the signal electrode, so that a plurality of micro thin film movables for optical communication can be moved. The element can be actively driven at high speed.

  According to a tenth aspect of the present invention, there is provided the small thin film movable element array including a control unit that performs switching driving of each of the movable units.

  In this small thin film movable element array, the movable part is driven and controlled by the control part, so that the absolute value of the inter-electrode voltage between the movable electrode and the fixed electrode decreases before the movable part reaches the final displacement position. Alternatively, it is increased or increased / decreased, and the overshoot and the vibration caused by the collision caused by the movable part reaching the final displacement position can be suppressed.

  According to the small thin film movable element for optical communication according to the present invention, there are a plurality of drive sources that apply a physical acting force to the movable part, and when the movable part is displaced in the first direction by the drive source, During the transition to the first direction, the driving source applies a physical action force that suppresses vibration of the movable part in a second direction different from the first direction to the movable part. It is possible to actively reduce the vibration at the time of contact of the movable part by applying a physical attractive force in the opposite direction. As a result, chattering can be reduced to reduce noise, and the switching operation in the small thin film movable element can be speeded up.

  According to the small thin film movable element array according to the present invention, vibration after the movable portion reaches the final displacement position is suppressed. Therefore, it is possible to eliminate or drastically shorten the vibration soothing time, and it is possible to write the address voltage without waiting for the vibration to settle. As a result, the driving cycle can be shortened and the switching operation can be speeded up.

Preferred embodiments of a small thin film movable element and a small thin film movable element array for optical communication according to the present invention will be described below with reference to the drawings.
FIG. 1 is a conceptual diagram showing a first embodiment of a small thin film movable element for optical communication according to the present invention by (a) and (b), and FIG. 2 is a diagram of vibration damping of the small thin film movable element shown in FIG. FIG. 3 is an explanatory diagram showing the behavior of the movable part to which the pulse waveform is applied, and FIG. 3 is an explanatory diagram showing the process represented by (a), (b), and (c).
An optical switch 100 as a small thin film movable element for optical communication according to the present embodiment includes, as basic components, a substrate 21 and a small piece-like movable portion 27 arranged in parallel to the substrate 21 via a gap 23. And hinges 29, 29 extending from both edge portions of the movable portion 27, and spacers 31, 31 that support the movable portion 27 on the substrate 21 via the hinges 29, 29. With such a configuration, the movable portion 27 can be rotationally displaced by the twisting of the hinges 29 and 29.

  In the optical switch 100, the upper surface of the movable portion 27 serves as a light reflecting portion (micromirror portion). In addition, the optical switch according to the present invention can also switch sound waves, fluids, and heat rays by appropriately selecting the material of the movable portion 27.

  In the present embodiment, the movable portion 27 is stopped without contacting the substrate 21 or a stop member (not shown) when reaching the final position of the displacement in the specific direction. That is, an optical switch as a non-contact type small thin film movable element for optical communication is configured.

  On the upper surface of the substrate 21, the first address electrode 35 a and the second address electrode 35 b are provided on both sides with the hinges 29 and 29 as the center. The movable part 27 is also provided with a movable electrode (not shown) in a part thereof. The optical switch 100 is provided with a drive circuit 37 in the substrate 21, and the drive circuit 37 applies a voltage between the movable part 27 and the first address electrode 35a, and between the movable part 27 and the second address electrode 35b. . As a basic operation, the optical switch 100 applies a voltage to the first address electrode 35a, the second address electrode 35b, and the movable portion 27, thereby swinging and displacing the movable portion 27 with the hinges 29 and 29 as twist centers. That is, when the movable part 27 is a micromirror part, the reflection direction of light is switched.

  In the optical switch 100, when a potential difference is given to the first address electrode 35a and the second address electrode 35b with respect to the movable portion 27, an electrostatic force is generated between the respective electrodes and the movable portion 27, and the hinges 29, 29 are generated. Rotational torque works around The electrostatic force generated at this time depends on the dielectric constant in vacuum, the area of the movable part 27, the applied voltage, and the distance between the movable part 27 and the address electrode.

  Therefore, when the dielectric constant in vacuum, the area of the movable portion 27, the distance between the movable portion 27 and the address electrode, and the elastic coefficients of the hinges 29 and 29 are constant, the movable portion 27 controls the potential of each electrode. Thus, it can be rotated and displaced to the left and right. For example, when Va> Vb, the electrostatic force generated in the first address electrode 35a and the movable portion 27 is larger than the electrostatic force generated in the second address electrode 35b and the movable portion 27, and the movable portion 27 is lowered on the left side. Lean on. On the other hand, when Va <Vb, the electrostatic force generated at the second address electrode 35b and the movable portion 27 is larger than the electrostatic force generated at the first address electrode 35a and the movable portion 27, and the movable portion 27 is located on the right side. Tilt down.

  As described above, the movable electrode of the movable portion 27, the first address electrode 35a, and the second address electrode 35b serve as a drive source for rotationally displacing the movable portion 27. Such a physical acting force applied from the drive source to the movable portion 27 becomes an electrostatic force, whereby high-speed rotational displacement is possible.

  The physical acting force that acts on the movable portion 27 may be a physical acting force other than the electrostatic force. As other physical acting force, for example, an effect by a piezoelectric body and an electromagnetic force can be cited. In this case, a piezoelectric actuator using a piezoelectric element or an electromagnetic actuator using a magnet / coil is employed as a drive source.

  As described above, the optical switch 100 includes the movable portion 27 that is displaced in both directions, and the movable portion 27 has a switching function. The movable portion 27 is rotationally displaced by a plurality of drive sources (movable electrodes of the movable portion 27, the first address electrode 35a, the second address electrode 35b) that apply a physical acting force. Here, in the optical switch 100 according to the present embodiment, when the movable unit 27 is driven to be displaced in the left rotation direction (first direction) in FIG. 1 by the drive source, the movable unit 27 changes to the first direction. In the meantime, a physical acting force that suppresses vibration of the movable part 27 is applied to the movable part 27 in a second direction different from the first direction by the drive source.

  As shown in FIG. 2A, first, the drive voltage Va is applied to the first address electrode 35a in the left rotation direction. Next, as shown in FIG. 2B, the vibration suppression voltage Vb is applied to the second address electrode 35b immediately before the left end of the movable portion 27 reaches the final displacement position. As a result, as shown in FIG. 2C, an electrostatic force is generated in the movable portion 27 and the second address electrode 35b by the vibration suppression voltage Vb, and this electrostatic force moves the right end of the movable portion 27 toward the substrate 21. Draw. This electrostatic attraction force acts as a vibration absorption effect, and the movable portion 27 comes to rest at the same time when it reaches the final position of displacement.

  As described above, when the movable portion 27 reaches the final position of the displacement in the specific direction, the instantaneous speed becomes substantially zero, so that the conventional movable portion reaches the final displacement position at a high speed. The vibration that has occurred due to the occurrence of overshoot beyond the rotation angle (convergence position) is not generated.

  When the movable portion 27 reaches the final position, the movable portion 27 is braked by the electrostatic attraction force and is forcibly controlled. And since the physical action force which acquires a vibration absorption effect is an electrostatic force, a high-speed vibration suppression force is obtained.

  Furthermore, physical action force is applied to a plurality of action points of the movable part 27 (left and right of the movable part 27 in the present embodiment), so that, for example, in the oscillating type movable part 27 whose center is the rotation center, Physical action force can be applied to both sides of the center of rotation, and different magnitudes of braking force can be applied to each action point at different timings, so that various braking effects can be obtained. .

  When the movable portion 27 rotates by applying the drive voltage Va shown in FIG. 3A, the vibration suppression voltage Vb for generating an electrostatic attractive force, that is, applied to the movable portion 27 and the second address electrode 35b. The voltage can be in the form of a pulse waveform with intensity (voltage) on the vertical axis and time on the horizontal axis shown in FIG. In this example, just before the movable part 27 reaches the final position of displacement, one pulse waveform p1 acting in the reverse direction of displacement is applied. Hereinafter, the pulse wave applied to the movable part 27 and the second address electrode 35b as the vibration suppression voltage Vb is applied to the "reverse pulse wave", and the drive voltage Va is applied to the movable part 27 and the first address electrode 35a. This pulse wave is referred to as “forward pulse wave”.

  By setting the vibration suppression voltage Vb to such a pulse waveform, an electrostatic attractive force is generated in a voltage range specified by the pulse waveform, and various braking effects can be obtained. Here, the pulse waveform includes a rectangular wave, a sine wave, a cosine wave, a sawtooth wave, a triangular wave, and a synthesized wave thereof.

  In this optical switch 100, while the movable part 27 is making a transition before reaching the final displacement position, a physical attractive force acts in a direction opposite to the transition direction, and immediately before the movable part 27 reaches the final displacement position. Will slow down. As a result, vibration due to overshoot that has occurred when the movable part reaches the final displacement position at a high speed and vibration due to collision when reaching the final displacement position by contact drive are suppressed. That is, the vibration of the movable part 27 can be actively reduced.

FIGS. 4A and 4B are explanatory views showing an example of applying a pulse voltage corresponding to the applied voltage to the drive unit, as (a) and (b).
The vibration suppression voltage Vb is set according to the drive voltage Va. That is, as shown in FIG. 4 (a), the drive voltage Va is also large oscillation suppressing voltage Vb is greater, also the movable portion 27 converge at a large rotational angle theta ₁ of the amplitude. If the drive voltage Va is small, as shown in FIG. 4B, the vibration suppression voltage Vb is also small, and the movable portion 27 is converged at the rotation angle θ ₂ having a small amplitude.

FIG. 5 is a perspective view showing an example of a three-dimensional optical switch having a movable part that is oscillated about two axes.
Further, the optical switch 100 twists the hinges 29a and 29a and the hinges 29b and 29b shown in FIG. 5 in addition to the uniaxial two-dimensional optical switch having a basic configuration with the hinges 29 and 29 shown in FIG. A two-axis three-dimensional optical switch 100A as the center may be used. In this case, the three-dimensional optical switch 100A is provided with a third address electrode 35c and a fourth address electrode 35d in addition to the first address electrode 35a and the second address electrode 35b. The movable portion 27 is driven in the X direction by applying a voltage to the first address electrode 35a, the second address electrode 35b, and the movable portion 27, and the third address electrode 35c, the fourth address electrode 35d, and the movable portion 27 are driven. The movable portion 27 is driven in the Y direction by applying a voltage to.

  Even in the case of such a three-dimensional optical switch 100A, during the transition before the movable portion 27 reaches the final displacement position, a physical attractive force acts in the direction opposite to the transition direction, and the movable portion 27 is finally moved. The speed immediately before reaching the displacement position is reduced. As a result, vibration due to overshoot is suppressed, and vibration of the movable portion 27 driven three-dimensionally can be actively reduced.

Next, modifications of various pulse waveforms applied to the vibration suppression voltage Vb and the drive voltage Va in order to generate an electrostatic attraction force that obtains a vibration absorption effect will be described.
FIG. 6 is an explanatory view showing Modification 1 in which two rectangular pulse waveforms are applied.
In the following embodiments and modifications, the same members / parts are denoted by the same reference numerals, and redundant description will be omitted.
In this modification, a plurality of pulse waves P2 and P3 in opposite directions are applied immediately before reaching the final displacement position of the movable portion 27. Although two pulse waves P2 and P3 are illustrated in the figure, the number of pulse waveforms may be two or more.
According to this modification, the electrostatic attractive force, which is a physical acting force, is applied at different magnitudes and at different timings, and various braking effects can be obtained.

FIG. 7 is an explanatory diagram showing a second modification in which a triangular pulse waveform is applied.
In this modification, the pulse wave P4 is a triangular wave. As described above, the pulse wave may be a triangular wave, a sine wave, or another waveform.
According to this modification, an electrostatic attraction force, which is a physical acting force, is applied at a steep timing that cannot be obtained with a rectangular wave.

FIG. 8 is an explanatory view showing Modification 3 in which two triangular pulse waveforms are applied.
In this modification, a plurality of triangular pulse waves P5 and P6 in opposite directions are applied immediately before reaching the final displacement position of the movable portion 27. In the figure, two triangular pulse waves P5 and P6 are illustrated, but two or more triangular pulse waveforms may be provided.
According to this modification, a steep electrostatic attraction force is applied at different magnitudes and at different timings.

FIG. 9 is an explanatory diagram showing a fourth modification in which a pulse waveform is applied to the drive voltage Va.
In this modification, after the pulse wave P2 in the reverse direction is applied immediately before the movable part 27 reaches the final position of displacement, the movable part 27 moves away from the final position of the displacement and then moves away. A forward pulse wave P7 is applied to the drive voltage Va. That is, after the movable portion 27 is displaced and driven in the left rotation direction (first direction), the drive source (the first address electrode 35a) is moved while the movable portion 27 transitions in the right rotation direction (second direction). The physical acting force is applied to the movable part 27 in the first direction by the movable part 27).
According to this modification, after the movable portion 27 is driven to be displaced in the first direction and reaches the final position of the displacement, the second moving portion 27 is further moved in the second direction by reaction or elastic force. A physical acting force in the direction of 1 is applied to the movable portion 27, so that the movement of the movable portion 27 that is going to move away from the final position of the displacement is actively braked.

FIG. 10 is an explanatory view showing Modification 5 in which a pulse waveform is applied to the braking electrode after a pulse waveform is applied to the drive voltage Va.
In this modification, the pulse wave P2 in the reverse direction and the pulse wave P7 in the forward direction are applied in the reverse order to the modification example shown in FIG. That is, a forward pulse wave P7 is applied immediately after the movable part 27 reaches the final position of displacement and moves away, and a reverse pulse wave P2 is generated immediately before the movable part 27 reaches the final position of displacement again. Applied.
According to this modification, after the movable part 27 reaches the final position of the displacement, the physical acting force in the first direction is changed in the second direction by reaction or elastic force. 27, the movement of the movable part 27 which is going to move away from the final position of the displacement is actively braked. Also, immediately before the movable part 27 that could not be stopped by this braking tries to reach the final position of the displacement again, a pulse wave P2 in the reverse direction is applied and the movable part 27 is reliably stopped.

FIG. 11 is an explanatory diagram showing a sixth modification in which the drive voltage Va is reduced at predetermined intervals.
In this modification, a reverse pulse wave P8 is applied immediately before the movable portion 27 reaches the final position of displacement, and at the same time, a forward pulse wave P9 with a reduced voltage is applied.
According to this modified example, immediately before the movable part 27 reaches the final position of displacement, braking is performed by the pulse wave P8 in the reverse direction, and the driving voltage Va at that time is canceled by the pulse wave P9. The movable portion 27 is braked with a greater force. In this case, the pulse wave P9 is lowered to 0V in the drawing, but the reduced voltage of the forward pulse wave P9 may not be 0V.

FIG. 12 is an explanatory diagram showing a modified example 7 in which a plurality of driving voltages Va are reduced at predetermined intervals.
In this modification, a plurality of reverse-direction pulse waves P2 and P3 are applied, and at the same time, forward-direction pulse waves P9 and P10 with a reduced voltage are applied.
According to this modification, the operation of the modification shown in FIG. 9 is repeated, and the movable portion 27 is braked more reliably.

FIG. 13 is an explanatory view showing a modified example 8 in which a constant voltage is applied after applying a pulse waveform.
In this modified example, the pulse wave P1 in the reverse direction is applied immediately before the movable portion 27 reaches the final position of displacement, but thereafter, the constant voltage Vb1 is continuously applied. In other words, the pulse wave in the reverse direction does not necessarily have to be 0 V at the normal time.
According to this modification, the movable portion 27 is biased in the reverse direction after reaching the final position of displacement. Thus, by making the difference between the bias voltage and the drive voltage a small voltage difference, the controllability such as the high-speed response of the movable portion 27 can be improved.

FIG. 14 is an explanatory view showing a modified example 9 in which a constant voltage is applied after applying a plurality of pulse waveforms.
In this modification, a plurality of pulse waves P2 and P3 in opposite directions are applied immediately before reaching the final position of the movable portion 27, and a constant voltage Vb1 is continuously applied during and after that.
According to this modification, a reliable vibration absorption effect can be obtained, and the movable portion 27 can be driven with a small voltage difference.

FIG. 15 is an explanatory diagram showing a modified example 10 in which a constant voltage is applied before a pulse waveform is applied.
In this modified example, the pulse wave P1 in the reverse direction is applied immediately before the movable portion 27 reaches the final position of the displacement, and thereafter, the constant voltage Vb1 is continuously applied, but the pulse wave P1 in the reverse direction is applied. Even before being applied, the constant voltage Vb1 is applied as the vibration suppression voltage Vb.
According to this modification, the movable part 27 is always biased in the reverse direction, and the movable part 27 can be driven with a small voltage difference. The vibration of the movable part 27 is always a balance between the electrostatic force in the forward direction and the reverse direction, and in the case of the contact type, it is pulled in (retracted) in the reverse direction of the range in which the movable part 27 maintains the contact state. If the voltage is constant, there is no problem even if it is always applied.

  Therefore, according to the optical switch described above, there are a plurality of drive sources that apply a physical acting force to the movable portion 27, and when the movable portion 27 is driven to be displaced in the first direction by the drive source, the movable portion 27 is the first Since the physical acting force is applied to the movable part 27 in the second direction different from the first direction by the drive source while the transition is in the direction of, the physical attractive force in the direction opposite to the transition direction of the movable part 27. And the vibration when reaching the final position of the movable portion 27 can be actively reduced. As a result, chattering can be reduced to reduce noise, and the switching operation in the optical switch 100 can be speeded up.

Next, a second embodiment of the small thin film movable element for optical communication according to the present invention will be described.
FIG. 16 is a conceptual diagram showing a second embodiment of the small thin film movable element for optical communication according to the present invention.
In the optical switch 200 according to the present embodiment, one end of the movable portion 41 is supported and fixed to the substrate 21 via hinges 29 and 29 and spacers 31 and 31. That is, the movable part 41 is configured in a cantilever shape with the other end being a free end. A first address electrode 35a is provided on the substrate 21 so as to face the free end of the movable portion 41, and is formed on a counter substrate (not shown) on the opposite side of the first address electrode 35a across the movable portion 41. A second address electrode 35b is provided.

  Even in the optical switch 200 having such a configuration, the drive voltage Va is applied to the first address electrode 35a and the movable portion 41, and the vibration suppression voltage Vb is applied to the second address electrode 35b and the movable portion 41, thereby moving the first switch. During the transition before the portion 27 reaches the final displacement position (in this case, the closest non-contact position on the first address electrode 35a side), an electrostatic attraction force is applied in the direction opposite to the transition direction, so that the movable portion The speed immediately before 27 reaches the final displacement position can be reduced.

  Thereby, it is possible to suppress the vibration caused by the collision that has occurred when the movable portion 27 reaches the final displacement position at a high speed. That is, vibration when the movable portion 27 reaches the final position can be actively reduced.

Next, a third embodiment of the small thin film movable element for optical communication according to the present invention will be described.
FIG. 17 is a conceptual diagram showing a third embodiment of the small thin film movable element for optical communication according to the present invention.
The optical switch 300 according to the present embodiment is a so-called parallel plate type element, and both ends of a plate-like movable portion 43 having conductivity and flexibility are formed on the insulating film 45 formed on the substrate 21 with a predetermined amount. The gap 47 is fixed. A first address electrode 35 a is disposed below the movable portion 43 of the substrate 21 via an insulating film 45, and a second address electrode is disposed above the movable portion 43 via an insulating film 49. 35b is disposed. In other words, the movable portion 43 is configured as a doubly supported beam in which both ends are supported between the first address electrode 35a and the second address electrode 35b.

  Also in such a parallel plate type optical switch 300, the drive voltage Va is applied to the first address electrode 35a and the movable portion 41, and the vibration suppression voltage Vb is applied to the second address electrode 35b and the movable portion 41. During the transition before the movable part 43 reaches the final displacement position (in this case, the closest non-contact position on the first address electrode 35a side), an electrostatic attractive force is applied in the direction opposite to the transition direction, The speed immediately before the movable part 43 reaches the final displacement position can be reduced.

  Further, the direction, structure, and driving of elements are not limited to the configuration of the optical switch in each of the above embodiments, and the present invention can be applied to all elements that are driven bidirectionally. .

FIG. 18 is an explanatory diagram showing the behavior of the movable part when the present invention is applied to a contact-type optical switch.
In each of the above-described embodiments and modifications, the case where the optical switch is a non-contact type has been described as an example. However, even when the present invention is applied to a contact-type optical switch, the same operations and effects as described above are achieved. It is what you play.

  That is, when the movable part 27 is driven to be displaced in the first direction by the drive source, while the movable part 27 is transitioning to the first direction, the drive source is different from the first direction with respect to the movable part 27. By applying a physical acting force in the direction 2 by the pulse wave P1, a physical attractive force is exerted in a direction opposite to the transition direction of the movable portion 27, and a reaction force or elasticity caused by the movable portion 27 coming into contact with the stop member. The movement is actively damped by the force to move away from the final position of the displacement. As a result, the switching operation in the contact-driven optical switch can be speeded up.

Each of the optical switches 100, 200, and 300 disclosed in the above embodiments can constitute an optical switch array by arranging them one-dimensionally or two-dimensionally.
In this optical switch array, optical switches 100, 200, and 300 capable of high-speed switching operation are arrayed, and the time required for vibration suppression can be shortened, and address voltage can be written earlier than before. .
Therefore, the vibration after the movable part reaches the final displacement position is suppressed, and it is possible to eliminate the vibration soothing time or to greatly reduce it, and to write the address voltage without having to wait for the vibration to settle. be able to. As a result, the switching operation can be speeded up and the driving cycle can be shortened.

  In addition, since an optical switch array for optical communication requires high accuracy, it is necessary to correct an operation error caused by variations in individual elements. Therefore, in the optical switch array, this correction must be performed for each element. On the other hand, according to the optical switch array according to the present embodiment, it is possible to easily correct the operation error by changing the applied voltage in each of the optical switches 100, 200, and 300 in correspondence with this correction. .

FIG. 19 is an explanatory diagram showing a configuration in which each of the optical switches has a drive circuit including a memory circuit.
Furthermore, the optical switch array 400 preferably includes a drive circuit 37 (see FIG. 1) in which each of the optical switches 100 includes a memory circuit 61. By providing such a memory circuit 61, an element displacement signal can be written to the memory circuit 61 in advance. That is, the element displacement signal is written in the memory circuit 61 in advance. When the optical switch 100 is switched, the drive voltage of the present invention is obtained by the element displacement signal stored in the memory circuit 61 of each optical switch 100 and the drive voltage control circuit 63 that controls the voltage applied to the optical switch 100. Is output to the signal electrode (first address electrode, second address electrode) 65 of the optical switch 100 at the timing of At this time, a desired voltage is also output to the common electrode (movable electrode) 67.
As described above, when the optical switch 100 is driven using the memory circuit 61, each of the plurality of optical switches 100 can be easily operated with an arbitrary driving pattern, and higher-speed active driving is possible. Here, the configuration of the optical switch array 100 of FIG. 1 is shown, but the configuration is not limited thereto, and optical switches 200 and 300 having other configurations may be used.

Further, the optical switch array 600 is preferably provided with a control circuit 63 as a control unit for switching and driving each movable unit 27.
In the optical switch array 400 provided with such a control circuit 63, the movable portion 27 is driven and controlled by the control circuit 63, so that the movable portion 27 (common electrode 67) is moved before the movable portion 27 reaches the final displacement position. ) And the fixed electrode (signal electrode 65), the absolute value of the inter-electrode voltage is decreased, increased, or increased and decreased, and the vibration caused by the collision caused by the movable part 27 reaching the final displacement position or over Shooting can be suppressed.

FIG. 20 is an explanatory diagram showing the configuration of a cross-connect switch using an optical switch.
The cross-connect switch 71 can be configured using, for example, an optical switch array 400 in which the optical switches 100 are arranged one-dimensionally. In the illustrated example, two optical switch arrays 400a and 400b are provided. In the cross-connect switch 71, the light emitted from the optical fiber 73a of the input fiber boat 73 passes through the microlens 75 and enters the predetermined optical switch 100a of one optical switch array 400a. The incident light becomes reflected light by the switching operation of the optical switch 100a and enters the desired optical switch 100b of the incident side optical switch array 400b. The incident light enters the optical fiber 77a of the predetermined output fiber board 77 by switching of the optical switch 100b.

  Also in this cross-connect switch 71, by using the optical switch array 400 including the plurality of optical switches 100, vibration when the movable part (micromirror part) 27 reaches the final position is actively reduced, and chattering is suppressed. By reducing the noise, the switching operation can be speeded up.

  In the cross-connect switch 71, the operation error can be easily corrected by changing the voltage applied to each optical switch 100 as described above. Error correction can be easily performed and high-accuracy switching can be performed.

  Further, in the cross-connect switch 71 described above, an example in which the optical switch 100 rotated by one axis is used, but the optical switch array includes the three-dimensional optical switch 100A rotated by two axes shown in FIG. It may be used. With this configuration, for example, even when the optical fibers 73a of the input fiber boat 73 are one-dimensionally arranged and the optical fibers 77a of the output fiber board 77 are two-dimensionally arranged, the movable portion 27 is three-dimensionally arranged. By driving, the emitted light from the optical fiber 73a can be switched to the desired optical fiber 77a in the direction perpendicular to the paper surface.

  Moreover, the timing and waveform of the voltage drive to each electrode mentioned above are not limited to this, and can be suitably changed as long as they do not depart from the gist of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS It is a conceptual diagram showing 1st Embodiment of the micro thin film movable element for optical communications which concerns on this invention with (a), (b). FIG. 3 is an operation explanatory diagram showing a vibration damping process of the small thin film movable element shown in FIG. 1 by (a), (b), and (c). It is explanatory drawing showing the behavior of the movable part to which the pulse waveform was applied. It is explanatory drawing which represented the example at the time of applying the pulse voltage according to the applied voltage to a drive part with (a), (b). It is a perspective view showing the example of the three-dimensional optical switch provided with the movable part rock | fluctuated by 2 axes | shafts. It is explanatory drawing showing the modification 1 to which two rectangular pulse waveforms are applied. It is explanatory drawing showing the modification 2 to which a triangular pulse waveform is applied. It is explanatory drawing showing the modification 3 to which two triangular pulse waveforms are applied. It is explanatory drawing showing the modification 4 by which a pulse waveform is applied to the drive voltage Va. It is explanatory drawing showing the modification 5 by which a pulse waveform is applied to a braking electrode after a pulse waveform is applied to the drive voltage Va. It is explanatory drawing showing the modification 6 by which the drive voltage Va is reduced by a predetermined space | interval. It is explanatory drawing showing the modification 7 by which the drive voltage Va is reduced by two or more by predetermined space | interval. It is explanatory drawing showing the modification 8 to which a fixed voltage is applied after a pulse waveform application. It is explanatory drawing showing the modification 9 to which a fixed voltage is applied after several pulse waveform application. It is explanatory drawing showing the modification 10 to which a fixed voltage is applied before a pulse waveform is applied. It is a conceptual diagram showing 2nd Embodiment of the micro thin film movable element for optical communications which concerns on this invention. It is a conceptual diagram showing 3rd Embodiment of the micro thin film movable element for optical communications which concerns on this invention. It is explanatory drawing showing the behavior of the movable part at the time of applying this invention to a contact-type optical switch. It is a top view showing 4th Embodiment which applied the small thin film movable element for optical communications which concerns on this invention to RF switch. It is explanatory drawing which shows the structure of the cross-connect switch in which the optical switch was used. It is explanatory drawing showing the vibration of the movable part which arises in the conventional optical switch. It is explanatory drawing of the braking pulse applied in the conventional micro mechanical lattice apparatus. It is explanatory drawing of the control signal applied in the control method of the conventional micromachine element.

Explanation of symbols

27 Movable part 35a First address electrode 35b Second address electrode 37 Drive circuit 61 Memory circuit 63 Control circuit (control part)
65 Signal electrode 67 Common electrode 100, 200, 300 Optical switch (micro thin film movable element for optical communication)
400 Optical switch array (small thin film movable element array)

Claims (10)

A movable part that is supported so as to be elastically displaceable and that is displaced in both directions, the movable part having a switching function for switching the output light of the optical fiber to any other optical fiber,
A plurality of drive sources for applying a physical acting force to the movable part;
When the movable part is displaced and driven in the first direction by the drive source, the first direction with respect to the movable part by the drive source is changed while the movable part is transitioning to the first direction. A small thin film movable element for optical communication, wherein a physical acting force that suppresses vibration of the movable portion is applied in different second directions.   After the movable portion is driven to move in the first direction, the drive source causes a physical action in the first direction with respect to the movable portion while the movable portion transitions in the second direction. 2. The small thin film movable element for optical communication according to claim 1, wherein force is applied.   3. The small thin film movable element for optical communication according to claim 1, wherein the physical acting force is applied to a plurality of acting points of the movable part.   The optical communication micro of any one of claims 1 to 3, wherein when the movable part reaches a final position of displacement in a specific direction, the speed of the movable part becomes substantially zero. Thin film movable element.   5. The physical action force that displaces the movable part in the first direction and the second direction by the drive source is an electrostatic force. 6. Small thin film movable element for optical communication.   6. The micro thin film movable for optical communication according to claim 1, wherein the physical acting force is applied in a pulse waveform with the vertical axis representing intensity and the horizontal axis representing time. element.   7. The small thin film movable element for optical communication according to claim 6, wherein the physical acting force is generated by a plurality of pulse waveforms.   A micro thin film movable element array, wherein the micro thin film movable elements for optical communication according to claim 1 are arranged one-dimensionally or two-dimensionally.   Each of the optical communication small thin film movable elements has a drive circuit including a memory circuit, and one of the electrodes provided on the movable part and at least two or more fixed parts facing the movable part is the 9. The small thin film movable element array according to claim 8, wherein a signal electrode to which an element displacement signal from the driving circuit is inputted and the other is a common electrode.   10. The small thin film movable element array according to claim 8, further comprising a control unit for switching and driving each of the movable units.

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