JP2007178587A - Micro actuator device, optical switch system, and optical equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the possibility of erroneous operation due to the leakage of remaining electric charge. <P>SOLUTION: The micro actuator device has a plurality of micro actuators and a driving circuit which drives the micro actuators. For respective capacitors Cmn which are formed of a fixed electrode and a movable electrode of the movable part of respective actuators, the driving circuit has: a row-selection signal interlocked switches Mmnaa and Mmnab which turn on and turn off interlocked with row-selection signals and complementarily; and column-selection signal interlocked switches Mnba and Mnbb which turn on and turn off linked with column-selection signals and complementarily. Thus, the electrodes of the capacitor Cmn are always connected to either of electric voltage supply terminals Va and Vb. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a microactuator device, and an optical switch system and an optical device using the same.

  With the progress of micromachining technology, the importance of microactuators is increasing in various fields. As an example of a field in which microactuators are used, for example, an optical switch that is used for optical communication or the like and switches an optical path can be cited. As an example of such an optical switch, for example, an optical switch disclosed in Patent Document 1 below can be cited.

  The microactuator that moves the micromirror used in the optical switch disclosed in Patent Document 1 has a movable portion that is movable with respect to the fixed portion, and the movable portion is moved upward by a spring force (microscopically). The mirror is configured to return to a position where incident light is reflected. The first electrode portion (fixed electrode) is disposed in the fixed portion, and the second electrode portion (movable electrode) and the Lorentz force current path are disposed in the movable portion. By passing a current through the current path for Lorentz force placed in the magnetic field, the movable part moves to a lower position (position where the micromirror passes the incident light as it is), and a voltage is applied between the first and second electrode parts. By applying, the movable part is held at the lower position. When the application of the voltage between the first and second electrode parts is stopped, the movable part returns to the upper position by the spring force.

Patent Document 1 discloses a device in which a plurality of microactuators are arrayed to form a plurality of optical switches, and a drive circuit used in the microactuator device in which microactuators are arrayed is also disclosed. In the drive circuit disclosed in Patent Document 1 (FIG. 7 of Patent Document 1), two selection switches (row selection switch and column selection switch) are provided for each microactuator with respect to the circuit portion related to electrostatic force. One of the first and second electrode portions of the microactuator is connected only to the two selection switches connected in series to a potential applied from the outside to supply a DC voltage. It had been.
JP 2003-159698 A

  In the driving circuit used in the conventional microactuator device, as described above, one of the first and second electrode portions of the microactuator is applied from the outside in order to supply a DC voltage. For the potential to be connected, only the two selection switches connected in series were connected. Therefore, in the microactuator in the unselected row or the unselected column, at least one of the row selection switch and the column selection switch is turned off, so that the microactuator is applied from a potential applied from the outside. If the capacitor is electrically disconnected and the movable part of the microactuator continues to be held at the lower position, it depends on the electrostatic force generated by the residual charge of the capacitor formed by the first and second electrode parts. Become. For this reason, in the microactuator device disclosed in Patent Document 1, it is necessary to make each capacitor so as to reduce the leakage of residual charges.

However, if the capacitance of the capacitor is reduced due to downsizing of the device, the amount of charge that can be accumulated in the capacitor is reduced. Therefore, in the conventional microactuator device, if it is attempted to reduce the size of the device, there is a possibility that the influence of residual charge leakage becomes larger and a sufficient electrostatic force cannot be maintained to cause a malfunction. There is a problem that the possibility of causing a malfunction due to the influence of the above becomes very high. Further, if the moving time of the movable portion is long, the time that the movable portion must be kept at the lower position by the electrostatic force due to the residual charge also becomes long, so the influence of the residual charge leakage becomes more serious.
In the drive circuit used in the conventional microactuator device, a DC voltage is used for generating an electrostatic force, but it is difficult to use an AC voltage for generating an electrostatic force. The reason will be clarified later in the description of the comparative example. Therefore, in the conventional microactuator device, if a DC voltage is continuously applied between the fixed electrode and the movable electrode for a long time, there is a problem that the movable portion is fixed to the fixed portion due to the effect of charge-up or the like. May occur.

  The present invention has been made in view of such circumstances, and provides a stable microactuator device that does not cause a malfunction due to the influence of leakage of residual charges, and an optical switch system and an optical device using the same. For the purpose.

  The present invention also provides a microactuator device that is stable without causing a malfunction due to the effect of leakage of residual charges, and that is suitable for using an AC voltage for generating an electrostatic force, and an optical switch system using the microactuator device And an optical device.

  In order to solve the above problems, a microactuator device according to a first aspect of the present invention includes a plurality of microactuators and a drive circuit that drives the plurality of microactuators, and (i) each of the microactuators includes: A movable part provided to be movable relative to the fixed part, a first electrode part provided to the movable part, and a voltage between the first electrode part provided to the fixed part and the first electrode part. A second electrode unit capable of generating electric power, and a driving force generation unit provided in the movable unit and capable of generating a driving force other than electrostatic force, and (ii) the driving circuit includes the plurality of microactuators. Multiple pairs of row selection signal interlocking switches that are turned on / off in conjunction with a row selection signal for selecting a row, and on / off in conjunction with a column selection signal for selecting the columns of the plurality of microactuators. A plurality of pairs of column selection signal interlocking switches and first and second potential supply terminals to which potentials are applied, respectively. (Iii) each pair of row selection signal interlocking switches is complementarily turned on. (2) Each pair of column selection signal interlocking switches is composed of two column selection signal interlocking switches that are turned on and off in a complementary manner, and (v) each of the above-described column selection signal interlocking switches. Regarding the microactuator, one of the first and second electrode portions of the microactuator is electrically connected to the first potential supply terminal, and (vi) the microactuator The other electrode portion of the first and second electrode portions of the actuator has the plurality of pairs of row selections regardless of the state of the row selection signal and the column selection signal. Of a total of four switches including a pair of row selection signal interlocking switches among the selection signal interlocking switches and a pair of column selection signal interlocking switches among the plurality of pairs of column selection signal interlocking switches, It is electrically connected to one of the first and second potential supply terminals via one or two switches.

  A microactuator device according to a second aspect of the present invention is the microactuator device according to the first aspect. (I) For each microactuator, two row selection signal interlocking switches (of the four switches related to the microactuator) Or one end of the column selection signal interlocking switch) is electrically connected to the other electrode portion of the first and second electrode portions of the microactuator, and (ii) for each microactuator, The other end of one row selection signal interlocking switch (or column selection signal interlocking switch) of the four switches related to the microactuator and two column selection signal interlocking switches (or row selection) of the four switches. One end of each signal interlocking switch) is electrically connected to each other; Regarding the tutor, the other end of the other one of the four switches related to the microactuator is electrically connected to the second potential supply terminal. (Iv) For each microactuator, the other end of one column selection signal interlocking switch (or row selection signal interlocking switch) of the four switches related to the microactuator is the first potential supply. (V) for each microactuator, the other end of the other one of the four switches associated with the microactuator (or the row selection signal interlocking switch). Is electrically connected to the second potential supply terminal.

  The microactuator device according to a third aspect of the present invention is the microactuator device according to the first or second aspect, wherein (i) each pair of row selection signal interlocking switches (or column selection signal interlocking switches) is provided for each microactuator. (Ii) Each pair of column selection signal interlocking switches (or row selection signal interlocking switches) is common to the column (or row) for each column (or row) of the plurality of microactuators. It is provided.

  The microactuator device according to a fourth aspect of the present invention is the microactuator device according to any one of the first to third aspects, wherein the driving force generation part of each microactuator is arranged in a magnetic field and generates a Lorentz force by energization. This is a current path for Lorentz force.

  A microactuator device according to a fifth aspect of the present invention is the microactuator device according to the fourth aspect, wherein the drive circuit includes a plurality of switches for selectively passing a current through the current path for the Lorentz force of the plurality of microactuators. It is what you have.

  An optical switch system according to a sixth aspect of the present invention includes the microactuator device according to any one of the first to fifth aspects, and a mirror provided in each of the movable portions of the plurality of microactuators. Is.

  An optical device according to a seventh aspect of the present invention includes the microactuator device according to any one of the first to fifth aspects, and an optical element provided in each of the movable portions of the plurality of microactuators. Is.

  According to the present invention, it is possible to provide a stable microactuator device that does not cause a malfunction due to the influence of residual charge leakage, and an optical switch system and an optical device using the microactuator device.

  In addition, according to the present invention, a microactuator device that is stable without causing a malfunction due to the influence of residual charge leakage and that is suitable for using an AC voltage for generating an electrostatic force, and a light using the same A switch system and an optical device can be provided.

  Hereinafter, a microactuator device, an optical switch system, and an optical device according to the present invention will be described with reference to the drawings.

  [First Embodiment]

  FIG. 1 is a schematic configuration diagram schematically showing an example of an optical system (in this embodiment, an optical switch system) including an optical switch array 1 according to the first embodiment of the present invention. For convenience of explanation, as shown in FIG. 1, an X axis, a Y axis, and a Z axis that are orthogonal to each other are defined (the same applies to the drawings described later). The surface of the substrate 11 of the optical switch array 1 is parallel to the XY plane. The direction of the arrow in the Z-axis direction is called the + Z direction or + Z side, and the opposite direction is called the -Z direction or -Z side, and the same applies to the X-axis direction and the Y-axis direction. The + side in the Z-axis direction may be referred to as the upper side, and the − side in the Z-axis direction may be referred to as the lower side. An arrangement in the X-axis direction is called a row, and an arrangement in the Y-axis direction is called a column. However, in the present invention, the column direction and the row direction are not necessarily orthogonal to each other.

  As shown in FIG. 1, this optical switch system includes an optical switch array 1, m optical input optical fibers 2, m optical output optical fibers 3, and n optical output optical fibers 4. In response to the optical path switching state command signal, the optical path switching state indicated by the optical path switching state command signal is realized in response to the magnet 5 as a magnetic field generating unit that generates a magnetic field as will be described later with respect to the optical switch array 1. And an external control circuit 6 serving as a control unit for supplying a control signal to the optical switch array 1. In the example shown in FIG. 1, m = 3 and n = 3, but m and n may each be an arbitrary number.

  In the present embodiment, as shown in FIG. 1, the magnet 5 is disposed below the optical switch array 1 and generates a magnetic field indicated by a magnetic force line 5 a with respect to the optical switch array 1. That is, the magnet 5 generates a substantially uniform magnetic field toward the + side along the Y-axis direction with respect to the optical switch array 1.

  As shown in FIG. 1, the optical switch array 1 includes a substrate 11 and m × n mirrors 31 arranged on the substrate 11. The m light input optical fibers 2 are arranged in a plane parallel to the XY plane so as to guide incident light from one side in the X axis direction to the substrate 11 in the X axis direction. The m optical output optical fibers 3 are arranged on the other side of the substrate 11 so as to face the m optical input optical fibers 2 and are not reflected by any mirror 31 of the optical switch array 1. Are arranged in a plane parallel to the XY plane so that light traveling in the X-axis direction is incident on the XY plane. The n light output optical fibers 4 are arranged in a plane parallel to the XY plane so that light reflected by any mirror 31 of the optical switch array 1 and traveling in the Y-axis direction is incident. . The m × n mirrors 31 can be moved in and out by a microactuator described later with respect to the intersection of the outgoing optical path of the m optical input optical fibers 2 and the incident optical path of the optical output optical fiber 4. It is arranged on the substrate 11 in a two-dimensional matrix so that it can move in the Z-axis direction. In this example, the orientation of the mirror 31 is set so that the normal line forms 45 ° with the X axis in a plane parallel to the XY plane. The optical path switching principle itself of this optical switch system is the same as the optical path switching principle of the conventional two-dimensional optical switch.

  FIG. 2 is a schematic plan view schematically showing the optical switch array 1 in FIG. The optical switch array 1 includes a substrate 11 (not shown in FIG. 2), m × n movable plates 12 arranged two-dimensionally on the substrate 11, and mirrors 31 mounted on each movable plate 12. And. In FIG. 1 and FIG. 2 and the drawings to be described later, nine optical switches are arranged in 3 rows and 3 columns for the sake of simplicity, but the number of optical switches is not limited at all. Portions other than the mirror 31 in the optical switch array 1 constitute a microactuator array that is a microactuator device according to an embodiment of the present invention.

  Next, the structure of one optical switch as a unit element of the optical switch array 1 in FIG. 1 will be described with reference to FIGS.

  FIG. 3 is a schematic plan view schematically showing one optical switch as a unit element of the optical switch array 1 in FIG. FIG. 4 is a schematic cross-sectional view along the line A-A ′ in FIG. 3. However, FIG. 4 shows only a cross section of the movable plate 12. FIG. 5 is a diagram showing a pattern shape of the Al film 22 when the movable plate 12 in FIG. 3 is viewed from above. In order to facilitate understanding, in FIG. 5, the Al film 22 is indicated by hatching. 6 and 7 are schematic cross-sectional views of the cross section taken along the line B-B ′ in FIGS. 3 and 5 as viewed from the + X side in the −X axis direction. However, FIGS. 6 and 7 also show the mirror 31 viewed in the −X-axis direction. FIG. 6 shows a state in which the mirror 31 is held on the upper side and advances into the optical path, and FIG. 7 shows a state in which the mirror 31 is held on the lower side and retracts from the optical path. 6 and 7, for convenience of drawing notation, the illustration of a convex portion 24 to be described later is omitted, and it is illustrated that there is no step.

  As shown in FIGS. 2 and 3, one optical switch as a unit element of the optical switch array 1 is provided on a substrate 11 such as a silicon substrate, and 1 as a movable part constituting one microactuator together with the substrate 11. Two movable plates 12 and a mirror 31 as an optical element which is a driven body mounted on the movable plate 12 are provided.

  The movable plate 12 is composed of a thin film, and as shown in FIGS. 3 to 7, the lower silicon nitride film (SiN film) 21 and the upper SiN film 23 over the entire planar shape of the movable plate 12, and these The intermediate Al film 22 is partially formed between the first and second films 21 and 23. That is, the movable plate 12 includes a part composed of a two-layer film in which SiN films 21 and 23 are laminated in order from the bottom, and a part composed of a three-layer film in which the SiN film 21, Al film 22, and SiN film 23 are laminated in order from the bottom. Have both. The pattern shape of the Al film 22 is as shown in FIG. 5, which will be described later. The movable plate 12 faces upward with respect to the substrate 11 as shown in FIG. 6 due to the internal stress generated by the difference in thermal expansion coefficient between the SiN films 21 and 23 and the Al film 22 and the internal stress generated at the time of film formation ( The film is formed with a predetermined film thickness and film formation conditions so as to be curved in the + Z direction.

  As shown in FIG. 3, the movable plate 12 includes a rectangular mirror mounting plate 12a as a mounting portion for mounting the mirror 31 (that is, a support base for the mirror 31), and an end portion of the mirror mounting plate 12a. And two strip-shaped support plates 12b connected to each other. In the present embodiment, these two support plates 12b are two beam portions mechanically connected in parallel to each other. The support plate 12b has a leg portion 12c and a leg portion 12d at each end. The legs 12c and 12d are both fixed to the substrate 11, and the movable plate 12 is lifted on the mirror mounting plate 12a side with the legs 12c and 12d as fixed ends, as shown in FIG. Thus, in the present embodiment, the movable plate 12 is a movable portion having a cantilever structure with the leg portions 12c and 12d as fixed ends. In the present embodiment, the substrate 11 and insulating films 13, 14, 15 and the like, which will be described later, laminated on the substrate 11 constitute a fixed portion.

  As shown in FIG. 3, the movable plate 12 is provided with a convex portion 24 so as to surround a region including a portion where the mirror 31 of the movable plate 12 is mounted. As shown in FIG. 4, the convex portion 24 is formed by making the multilayer film constituting the movable plate 12 convex. By providing the convex portion 24 in this manner, a step is generated. Therefore, in the movable plate 12, the region surrounded by the convex portion 24 and the region provided with the convex portion 24 are suppressed from bending due to internal stress and are flat. Sex can be maintained. Therefore, even when the movable plate 12 is in a state where the mirror 31 is lifted to the upper position by bending due to internal stress as shown in FIG. The shape of the mirror 31 can be kept constant.

  As described above, in the movable plate 12, the region surrounded by the convex portion 24 and the region provided with the convex portion 24 are suppressed from being curved, but the region close to the leg portion 12 d of the support plate 12 b has the convex portion 24. Not provided. Thereby, due to the curvature of the region of the support plate 12b where the convex portion 24 is not provided, the movable plate 12 is lifted on the mirror mounting plate 12a side as shown in FIG. 6 with the leg portions 12c and 12d as fixed ends. ing. Moreover, the area | region near the leg part 12d of the support plate 12b becomes the leaf | plate spring part as an elastic part by the convex part 24 not being provided.

  Here, the shape of the Al film 22 of the movable plate 12 will be described with reference to FIG. In the present embodiment, in order to drive the movable plate 12 using both Lorentz force and electrostatic force as driving forces, the Al film 22 is patterned into a shape as shown in FIG. The pattern 22 a of the Al film 22 extends from each of the two leg portions 12 d along the outer peripheral edge of the movable plate 12 to the distal end side (+ Y side) of the movable plate 12, and one side of the distal end of the movable plate 12. 12e is connected to a linear pattern 22c extending in the X-axis direction along 12e. The pattern 22c is a current path (Lorentz force current path) that is arranged in a magnetic field and generates a Lorentz force as a driving force when energized. Hereinafter, the pattern 22c may be referred to as a Lorentz force current path 22c. The pattern 22 c is also a pattern in the Al film 22. The pattern 22a is a wiring pattern for supplying current to the Lorentz force current path 22c. As shown in FIGS. 6 and 7, the pattern 22a is connected to the Lorentz force wiring pattern 42a made of an Al film or the like through the contact hole of the insulating film 15 and the SiN film 21 at the leg portion 12d on the + X side. , The leg portion 12d on the −X side is similarly connected to another Lorentz force wiring pattern 42a (not shown in FIGS. 6 and 7), and the Lorentz force wiring pattern is driven from the Lorentz force wiring pattern via the leg portion 12d. A current as a signal is supplied. The Lorentz force current path 22c is placed in the magnetic field in the Y-axis direction by the magnet 5 shown in FIG. Therefore, when a current is supplied to the Lorentz force current path 22c via the pattern 22a, a Lorentz force in the + Z direction or the −Z direction is generated in the Lorentz force current path 22c depending on the direction of the current.

  As shown in FIGS. 6 and 7, insulating films 13, 14, 15 such as a silicon oxide film are sequentially stacked on the substrate 11 from the substrate 11 side, and the Lorentz force wiring pattern 42 a includes the insulating film 14. , 15 are formed.

  Further, the pattern 22b of the Al film 22 extends from each of the two leg portions 12c to the distal end side (+ Y side) of the movable plate 12 along the inner edge of the movable plate 12, and is a rectangle disposed on the distal end side. Connected to the pattern 22d. The pattern 22d is a movable electrode for generating an electrostatic force as a driving force. Hereinafter, the pattern 22d may be referred to as the movable electrode 22d. The pattern 22 d is also a pattern in the Al film 22. The pattern 22b is a wiring pattern of the movable electrode 22d. The pattern 22b is connected to a movable electrode wiring pattern (not shown) through the contact hole of the insulating film 15 and the SiN film 21 in the leg portion 12c, and is connected to a fixed electrode 41a made of an Al film (static voltage). Power voltage, electrostatic force drive signal) is applied. The fixed electrode 41a is formed between the insulating films 13 and 14 on the substrate 11, and is disposed at a position facing the movable electrode 22d. When a voltage is applied between the movable electrode 22d and the fixed electrode 41a, an electrostatic force as a driving force is generated between them, and the movable plate 12 is attracted to the substrate 11 by this electrostatic force.

  In the present embodiment, the mirror 31 is held on the upper side (opposite side of the substrate 11) by controlling the electrostatic force voltage between the movable electrode 22d and the fixed electrode 41a and the current flowing through the Lorentz force current path 22c. The state (FIG. 6) and the state where the mirror 31 is held on the lower side (substrate 11 side) (FIG. 7) can be obtained. In the present embodiment, as will be described later, such control is performed by an external control circuit 6 in FIG. 1 and a drive circuit shown in FIG. 8 described later mounted on the microactuator array. 6 and 7, K indicates a cross section of the optical path of the incident light with respect to the advance position of the mirror 31.

  Here, focusing on one optical switch, an operation example thereof will be described. In the following description, a current that flows through the Lorentz force current path 22c and causes a Lorentz force is referred to as a Lorentz force current, and a voltage applied between the movable electrode 22d and the fixed electrode 41a is referred to as an electrostatic force voltage.

  First, the current for Lorentz force is zero, the voltage for electrostatic force is zero, and the film is bent in the + Z direction by the stress (spring force) of the film in the region of the support plate 12b where the convex portion 24 is not provided. It is assumed that the mirror 31 has returned and is held at the upper position as shown in FIG. In this state, the mirror 31 advances into the optical path K and reflects the light incident on the optical path K. In the present embodiment, even if the Lorentz force current remains zero and the electrostatic force voltage is set to V in the state shown in FIG. 6, the distance between the electrodes 22d and 41a is large, so that the voltage is generated between the two. It is set so that the electrostatic force substantially disappears and the state shown in FIG. 6 is maintained.

  Thereafter, when the position of the mirror 31 is switched to the lower position shown in FIG. 7, the Lorentz force current is set to + I. Here, + I is a current that causes the Lorentz force current path 22c to generate a downward Lorentz force that is stronger than the spring force. The mirror 31 is lowered by the Lorentz force, stops when the movable plate 12 contacts the substrate 11, and is held at the lower position shown in FIG. Then, after setting the electrostatic force voltage to V, the current for Lorentz force is made zero. In this state, since the distance between the electrodes 22d and 41a is small, the electrostatic force between them is sufficiently larger than the spring force, so the state shown in FIG. 6 is maintained. When the position of the mirror 31 is switched to the lower position shown in FIG. 7, the electrostatic force voltage may be set to V before the Lorentz force current is set to + I.

  When the mirror 31 is located at the lower position shown in FIG. 7, the incident light is not reflected by the mirror 31 but passes as it is to become outgoing light.

  Thereafter, when the position of the mirror 31 is switched to the upper position shown in FIG. 6, the electrostatic force voltage is set to zero. As a result, the mirror 31 moves upward by the spring force, returns to the upper position shown in FIG. 6, and continues to be held at the upper position by the spring force.

  FIG. 8 is an electric circuit diagram showing the optical switch array 1 according to the present embodiment. The single optical switch shown in FIGS. 3 to 7 includes one capacitor (corresponding to a capacitor formed by the fixed electrode 41a and the movable electrode 22d) and one coil (a Lorentz force current) in terms of electrical circuit. Equivalent to the path 22c). In FIG. 8, the capacitors and coils of the optical switch of m rows and n columns are denoted as Cmn and Lmn, respectively. For example, the capacitors and coils of the optical switch at the upper left (first row and first column) in FIG. 2 are denoted as C11 and L11, respectively. In the present embodiment, the left side of the capacitor Cmn is the fixed electrode 41a, and the right side is the movable electrode 22d. But you may reverse both.

  In FIG. 8, in order to simplify the description, nine optical switches are arranged in three rows and three columns as described above. However, the number of optical switches is not limited at all, and the principle is the same even when, for example, an optical switch having 100 rows and 100 columns is provided.

  In the following description, for convenience of explanation, it is assumed that each switch is turned on when its gate becomes high level and turned off when its gate becomes low level. This applies not only to the case of FIG. 8 but also to the cases of FIGS. 12 and 15 described later.

  In the circuit shown in FIG. 8, with respect to the capacitor Cmn, a row selection terminal VVm for supplying a row selection signal for each row and a column selection terminal VHn for supplying a column selection signal for each column are provided. . Regarding the coil Lmn, a row selection terminal IVm for supplying a row selection signal for each row and a column selection terminal IHn for supplying a column selection signal for each column are provided. In addition, a first potential supply terminal Vb for applying a first potential based on a predetermined reference potential, and a second potential supply terminal Va for applying a second potential based on the reference potential. , And a current control terminal C3 is provided.

  As shown in FIG. 8, a pair of row selection signal interlocking switches Mmnaa and Mmnab are provided for each capacitor Cmn. The gate of one row selection signal interlocking switch Mmnaa of each row m is connected to the row selection terminal VVm of the same row m, and the row selection signal is input non-inverted to the gate of the row selection signal interlocking switch Mmnaa. The gate of the other row selection signal interlocking switch Mmnab of each row m is connected to the row selection terminal VVm of the same row m via a knot gate NVVm, and the inverted signal of the row selection signal is connected to the gate of the row selection signal interlocking switch Mmnab. Entered. As a result, the pair of row selection signal interlocking switches Mmnaa and Mmnab are turned on / off in conjunction with the row selection signal and complementarily turned on / off.

  For each capacitor, a pair of column selection signal interlocking switches Mba, Mnbb is provided in common for the capacitor Cmn. The gate of one row selection signal interlocking switch Mnb of each column n is connected to the column selection terminal VHn of the same column n, and the column selection signal is input non-inverted to the gate of the column selection signal interlocking switch Mnbb. The gate of the other column selection signal interlocking switch Mnbb of each column n is connected to the column selection terminal VHn of the same column n via a not gate NVHn, and the inverted signal of the row selection signal is connected to the gate of the column selection signal interlocking switch Mnbb. Is entered. As a result, the pair of column selection signal interlocking switches Mnba and Mnbb are turned on / off in conjunction with the column selection signal and are complementarily turned on / off.

  In this way, a pair of column selection signal interlocking switches Mnba and Mnbb are provided in common for each column, but in relation to each capacitor Cmn, two row selection signal interlocking switches Mmnaa, A total of four switches, Mmnab and two column selection signal interlocking switches Mba and Mnb, are provided. For example, a total of four switches including two row selection signal interlocking switches M11aa and M11ab and two column selection signal interlocking switches M1ba and M1bb are provided in association with the capacitor C11. In addition, for example, a total of four switches including two row selection signal interlocking switches M12aa and M12ab and two column selection signal interlocking switches M1ba and M1bb are provided in association with the capacitor C12.

  The fixed electrodes 41a of all the capacitors Cmn are electrically connected to the first potential supply terminal Vb.

  For each capacitor Cmn, one end of each of the two row selection signal interlocking switches Mmnaa and Mmnab among the four switches Mmnaa, Mmnab, Mnba, and Mnbb related to the capacitor Cmn is electrically connected to the movable electrode 22d of the capacitor Cmn. It is connected.

  For each capacitor Cmn, the other end of one row selection signal interlocking switch Mmnaa among the four switches Mmnaa, Mmnab, Mnba, Mnbb related to the capacitor Cmn, and among the four switches Mmnaa, Mmnab, Mnba, Mnbb Are connected electrically to one end of each of the two column selection signal interlocking switches Mba and Mnbb.

  For each capacitor Cmn, the other end of one other row selection signal interlocking switch Mmnab among the four switches Mmnaa, Mmnab, Mnba, Mnbb related to the capacitor Cmn is electrically connected to the second potential supply terminal Va. It is connected.

  For each capacitor Cmn, the other end of one column selection signal interlocking switch Mnba among the four switches Mmnaa, Mmnab, Mnba, and Mnbb related to the capacitor Cmn is electrically connected to the first potential supply terminal Vb. ing.

  For each capacitor Cmn, the other end of one other column selection signal interlocking switch Mnbb among the four switches Mmnaa, Mmnab, Mnba, and Mnbb related to the capacitor Cmn is electrically connected to the second potential supply terminal Va. It is connected.

  In this embodiment, by connecting in this way, the movable electrode 22d of the capacitor Cmn is related to the capacitor Cmn regardless of the row selection signal and the column selection signal in each state. Electrically connected to one of the first and second potential supply terminals Vb and Va via one or two of the switches Mmnaa, Mmnab, Mnba and Mnb It has come to be.

  For example, the row selection terminal VV1 and the column selection switch VH1 related to the capacitor C11 are (i) VV1 is high level and VH1 is high level, (ii) VV1 is high level and VH1 is low level, (iii) VV1 Are in a low level and VH1 is in a high level, and (iv) VV1 is in a low level and VH1 is in a low level. In the state (i), M11aa is on, M11ab is off, M1ba is on, M1bb is off, and the movable electrode 22d of the capacitor C11 passes through the two switches M11aa and M1ba, and the first potential supply terminal Vb. Is electrically connected. In the state (ii), M11aa is turned on, M11ab is turned off, M1ba is turned off, M1bb is turned on, and the movable electrode 22d of the capacitor C11 passes through the two switches M11aa and M1bb, and the second potential supply terminal Va. Is electrically connected. In the state (iii), M11aa is turned off, M11ab is turned on, M1ba is turned on, M1bb is turned off, and the movable electrode 22d of the capacitor C11 is electrically connected to the second potential supply terminal Va via one switch M11ab. Connected. In the state (iv), M11aa is turned off, M11ab is turned on, M1ba is turned off, and M1bb is turned on. The movable electrode 22d of the capacitor C11 is electrically connected to the second potential supply terminal Va via one switch M1ab. Connected.

  In the circuit shown in FIG. 8, a coil row selection switch Mmnc is provided for each coil Lmn. A coil column selection switch Mnd is commonly provided for each column of the coil Lmn. One end of the coil Lmn is connected to one end of the row selection switch Mmnc, the other end of the row selection switch Mmnc is connected to one end of the column selection switch Mnd, and the other end of the column selection switch Mnd is connected to one end of the current control switch MC3. ing. The other end of the coil Lmn is grounded (connected to a part having a ground potential). The other end of the current control switch MC3 is connected to one end of a current source I1 that supplies the current + I, and the other end of the current source I1 is grounded. The gate of the current control switch MC3 is connected to the terminal C3. The gate of the row selection switch Mmnc of each row m is connected to the coil row selection terminal IVm of the same row m. The gate of each column n coil column selection switch Mnd is connected to the coil column selection terminal IHn of that column n.

  Each switch described above can be configured by a MOS transistor formed on the substrate 11 when a silicon substrate is used as the substrate 11.

  FIG. 9 is a diagram showing an example of potentials applied to the first and second potential supply terminals Vb and Va in FIG. FIG. 10 is a diagram showing another example of potentials applied to the first and second potential supply terminals Vb and Va in FIG.

  In the example shown in FIG. 9, a DC potential + Vc based on the reference potential is applied to the potential supply terminal Va, and a reference potential (for example, ground potential) is applied to the potential supply terminal Vb. In the case of FIG. 9, a DC power source may be connected between the terminals Vb and Va.

  In the example shown in FIG. 10, an AC pulse potential that alternates + Vc and −Vc with reference to a reference potential (for example, ground potential) is applied to the potential supply terminal Va, and a reference potential (for example, ground) is applied to the potential supply terminal Vb. An alternating pulse potential alternating between + Vc and -Vc with respect to (potential) is applied, and both are in opposite phases. Thereby, AC pulse driving is performed.

  In the present embodiment, a DC drive as shown in FIG. 9 may be adopted, or an AC drive as shown in FIG. 10 may be adopted. However, in order to avoid the influence of charge-up or the like, it is preferable to employ AC driving as shown in FIG.

  Next, FIG. 11 shows an example of a timing chart of voltages applied to the terminals C3, VV1 to VV3, VH1 to VH3, IV1 to IV3, IH1 to IH3.

  In the present embodiment, the voltages of the terminal terminals C3, VV1 to VV3, VH1 to VH3, IV1 to IV3, IH1 to IH3 are supplied as control signals from the external control circuit 6 in FIG. For example, the external control circuit 6 checks the optical switch to be changed from the current movable plate position state based on the optical path switching state command signal, and sets the state change period to 1 for each of the optical switches to be changed. Set sequentially one by one. When there is no optical switch to be changed from the current position state, a state holding period is set. Further, when a plurality of state holding periods are set (that is, when the number of optical switches to be changed from the current position state is two or more), the state holding periods may be set between the state changing periods. It is good or not necessary. For example, when there are three optical switches to be changed from the current position state, the state change period → the state holding period → the state changing period → the state holding period → the state changing period may be set, or continuously Then, the state change period may be set. Then, the external control circuit 6 sets the terminals C3, VV1 to VV3, VH1 to VH3, IV1 to IV3, IH1 to IH3 according to the address of the corresponding optical switch and the movable plate position state in each set state change period. Determine the voltage.

  FIG. 11 shows a state holding period → the state change period of the optical switch in the first row and the first column (release operation (the target optical switch is changed from the lower position shown in FIG. 7 to the upper position shown in FIG. 6). State changing period) → state holding period → state change period of the optical switch in the first row and first column (latching operation (the target optical switch is changed from the upper position shown in FIG. 6 to the lower position shown in FIG. 7) In this example, a state change period in which the operation is performed) → the state holding period is set.

  In FIG. 11, the period before time t1 is a state holding period. In this period, the terminals C3, VV1 to VV3, VH1 to VH3, IV1 to IV3, IH1 to IH3 are at a low level. In this state, the fixed electrode 41a of the capacitor Cmn is directly connected to the first potential supply terminal Vb, and the movable electrode 22d of the capacitor Cmn is connected to the second potential supply terminal via the row selection signal interlocking switch Mmnab in the on state. Since it is connected to Va, a potential difference between terminals Va and Vb (Vc in the case of FIG. 9, 2Vc in the case of FIG. 10) is applied to all the capacitors Cmn, and current is supplied to all the coils Lmn. The mirror 31 of each optical switch is held at either the upper position shown in FIG. 6 or the lower position shown in FIG. Here, it is assumed that the mirror 31 of the optical switch in the first row and first column is held at the lower position shown in FIG.

  At time t1, a state change period (state change period in which release operation is performed) for the optical switch in the first row and first column is started, and the terminals VV1 and VH1 are set to the high level, and the other terminals are All remain low.

  At this time, one row selection signal interlocking switch M11ab, M12ab, M13ab of the first row is switched off, and the other M11aa, M12aa, M13aa of the first row is switched on, but the row selection signal interlocking switch of the other row is switched on. There is no change in the state. Also, one column selection signal interlocking switch M1ba of the first column is switched on, and the other column selection signal interlocking switch M1bb of the first column is switched off, but the state of the column selection signal interlocking switch of the other column is changed. There is no.

  Therefore, after time t1, the movable electrode 22d of the capacitor C11 in the first row and first column is connected to the first potential supply terminal Vb via the row selection signal interlocking switches M11aa and M1ba in the on state. For this reason, since the fixed electrode 41a of the capacitor C11 is directly connected to the first potential supply terminal Vb in the first place, a potential difference of zero is applied to the capacitor C11, and the bias voltage of the capacitor C11 becomes zero. As a result, the mirror 31 of the optical switch in the first row and first column moves to the upper position shown in FIG. 6 by the stress (spring force) of the film in the region of the support plate 12b where the convex portions 24 are not provided.

  After time t1, the terminal Va is connected to the movable electrode portion 22d of the other capacitor, and the potential difference between the terminals Va and Vb (Vc in the case of FIG. 9, 2Vc in the case of FIG. 10) is connected to the other capacitor. Is applied. Thus, according to the present embodiment, all the capacitors Cmn are not electrically disconnected from any one of the potential supply terminals Va and Vb even in the state change period.

  Thereafter, at time t2, the terminals VV1 and VH1 are changed to the low level, thereby shifting to the state holding period.

  After this state holding period, at time t3, a state change period (state change period in which the latch operation is performed) for the optical switch in the first row and first column is started, and the terminals IV1 and IH1 are set to the high level. Is done. As a result, the first coil row selections M11c, M12c, M13c and the first coil column selection switch M1d are turned on. Next, at time t4, the terminal C3 is set to the high level, and the current control switch MC3 is switched on. As a result, a current for Lorentz force flows through the coil L11 of the first row and first column optical switch, and the downward Lorentz force generated thereby causes the mirror 31 of the first row and first column optical switch to move to the lower position shown in FIG. Moving.

  Thereafter, at time t5, the terminal C3 is set to low level, and the current control switch MC3 is switched off. As a result, the downward Lorentz force does not act, but since the potential difference between the terminals Va and Vb (Vc in the case of FIG. 9 and 2 Vc in the case of FIG. 10) is applied to the capacitor C11, the electrostatic force generated thereby. Thus, the mirror 31 is continuously held at the lower position shown in FIG.

  Further, at time t6, the terminals IV1 and IH1 are set to the low level, and the state holding period is started.

  As can be seen from the above description, according to the present embodiment, row selection signal interlocking switches Mmnaa and Mmnab that are complementarily turned on / off, and column selection signal interlocking switches Mmnba and Mmnbb that are complementarily on / off. By skillfully utilizing these, the fixed electrode 41a and the movable electrode 22d of the capacitor Cmn are connected to one of the potential supply terminals Va and Vb in any period including the state change period, and the fixed electrode 41a In addition, the movable electrode 22d is not electrically floated. Therefore, unlike the above-described prior art, the residual charge of the capacitor Cmn is not used, so there is no possibility of malfunction due to the influence of residual charge leakage, and stable operation can be performed.

  Further, from the above-described operation description, in the present embodiment, not only can DC drive be performed as shown in FIG. 9, but AC drive is appropriately performed without causing any trouble as shown in FIG. You can see that As described above, the present embodiment is also suitable for using an AC voltage for generating an electrostatic force.

  Here, an optical switch array according to a comparative example obtained by modifying the optical switch array 1 according to the present embodiment will be described with reference to FIG.

  FIG. 12 is an electric circuit diagram showing an optical switch array according to this comparative example. 12, elements that are the same as or correspond to those in FIG. 8 are given the same reference numerals, and redundant descriptions thereof are omitted. This comparative example is different from the present embodiment only in the drive circuit. The drive circuit shown in FIG. 12 is substantially the same as the drive circuit disclosed in FIG.

  In this comparative example, as shown in FIG. 12, a row selection switch Mmna corresponding to the row selection signal interlocking switch Mmnaa in FIG. 8 is provided for each capacitor Cmn, but the row selection in FIG. A switch corresponding to the signal interlock switch Mmnab is not provided. Further, in this comparative example, a column selection switch corresponding to the column selection signal interlocking switch Mnb in FIG. 8 is provided in common for the column for each column with respect to the capacitor Cmn. No switch corresponding to the middle column selection signal interlocking switch Mnbb is provided. Accordingly, the knot gates NVVm and NVHn in FIG. 8 are not provided in this comparative example.

  A terminal Vm in FIG. 12 is a row selection terminal that is used for both the capacitor Cmn and the coil Lmn, and corresponds to a terminal that also uses the terminals VVm and IVm in FIG. Similarly, a terminal Hn in FIG. 12 is a column selection terminal that is used for both the capacitor Cmn and the coil Lmn, and corresponds to the terminal that is also used as the terminals VHn and IHn in FIG.

  In this comparative example, the potential supply terminals Va and Vb in FIG. 8 are not provided, and the fixed electrodes 41a of all the capacitors Cmn are grounded. As shown in FIG. 12, voltage control switches MC1 and MC2 are provided, and their gates are connected to terminals C1 and C2, respectively. One end of the voltage control switch MC1 and one end of the voltage control switch MC2 are connected to each other, and further connected to one end of the column selection switch Mnb. The other end of the voltage control switch MC1 is connected to a DC clamp voltage VC, and the other end of the voltage control switch MC2 is grounded.

  Next, FIG. 13 shows an example of a timing chart of voltages applied to the terminals C1 to C3, V1 to V3, and H1 to H3 in this comparative example. The operation example shown in FIG. 13 corresponds to the operation example of the present embodiment shown in FIG. 11 described above.

  FIG. 13 shows a voltage refresh period → a state change period (release operation) of the optical switch in the first row and first column → a voltage refresh period → a state change period (latching operation) of the optical switch in the first row and first column → the voltage refresh period. This is a set example. The voltage refresh period is a part of the state holding period.

  FIG. 13, before time t11 is a voltage refresh period in which the capacitors Cmn of all optical switches are biased to the clamp voltage VC. Therefore, in this period, the terminals V1 to V3, H1 to H3, and C1 are all set to the high level, the terminals C2 and C3 are set to the low level, and the mirror 31 of each optical switch is positioned at the upper position shown in FIG. Is held at one of the lower positions shown in FIG. Here, it is assumed that the mirror 31 of the optical switch in the first row and first column is held at the lower position shown in FIG.

  At time t11, a state change period (state change period in which the release operation is performed) for the optical switch in the first row and first column is started, the terminals V2, V3, H2, and H3 are set to the low level, and the capacitor C11 Other capacitors are electrically disconnected.

  Next, after the terminal C1 is set to the low level at time t12, the terminal C2 is set to the high level at time t13, the charge charged in the capacitor C11 is discharged, and the electrostatic force voltage of the capacitor C11 is reduced to zero. The As a result, there is no electrostatic force between the fixed electrode 41a and the movable electrode 22d of the first row and first column optical switch, and the mirror 31 of the first row and first column optical switch moves to the upper position shown in FIG. Held. Next, the terminal C2 is set to low level at time t14, and the terminal C1 is set to high level at time t5.

  Thereafter, at time t16, the terminals V2, V3, H2, and H3 are set to the high level to shift to the voltage refresh period.

  After this voltage refresh period, at time t17, a state change period (state change period in which the latch operation is performed) for changing the state of the optical switch in the first row and first column is started, and the terminals V2, V3, H2, and H3 are connected. At low level, the coil L11 is selected and capacitors other than the capacitor C11 are electrically disconnected.

  Next, at time t18, the terminal C3 is set to the high level, and a current for Lorentz force flows through the coil L11. Due to the downward Lorentz force thereby, the mirror 31 moves to the lower position shown in FIG. Thereafter, at time t19, the terminal C3 is set to the low level, and the Lorentz force current stops and the Lorentz force is not generated. However, the mirror 31 is continuously held at the lower position by the electrostatic force of the capacitor C11.

  Thereafter, at time t20, the terminals V2, V3, H2, and H3 are set to the high level to shift to the voltage refresh period.

In this comparative example, two selection switches M11a and M1b are connected in series to the movable electrode 22d of each capacitor Cmn (for example, the selection switches M21 and M1b are connected in series to the capacitor C21), and the selection switch M11a. , There is no current path that bypasses M1b. For this reason, as can be seen from the above description of the operation, in the state change period t11-t6 and the state hold period t17-t20, capacitors other than the capacitor C11 are electrically disconnected. The holding of the lower position of the mirror 31 of the optical switch other than the optical switch shown in FIG. 7 relies on the electrostatic force generated by the charge remaining in the capacitor. For this reason, in this comparative example, each capacitor may be affected by the leakage of residual charges and malfunction.
In this comparative example, a DC voltage is used for generating an electrostatic force. However, it is difficult to use an AC voltage for generating an electrostatic force for the reason described below.

  Now, consider applying an AC pulse as shown in FIG. 14 instead of the DC voltage VC in the circuit shown in FIG. Then, when the timing for shifting to the state change period (for example, time t11 and time t17 in FIG. 13) is the time T1 and T3 in FIG. Since the charge of the voltage + Vc or −Vc remains, the capacitor of the optical switch other than the state change target can be held at the lower position in the state change period as in the case of the DC drive. However, when the timing for shifting to the state change period coincides with the polarity switching timing as at times T2 and T4 in FIG. 14, the capacitor of the optical switch other than the state change target has almost no charge at that time. The capacitor of the optical switch other than the state change target cannot be held at the lower position. For this reason, when an AC pulse as shown in FIG. 14 is applied instead of the DC voltage VC, advanced timing control is performed so that the transition timing to the state change period is a timing such as times T1 and T3. It becomes necessary and the circuit configuration becomes complicated.

  Even if such timing control is realized, a circuit having a withstand voltage of 2 VC is required to obtain an electrostatic force of voltage VC, which is not practical. In order to solve this, in general AC driving of the electrostatic force electrode, a method is used in which the potential of one electrode is not ground but an AC pulse voltage having a phase opposite to that of the other electrode is applied. However, in the comparative example shown in FIG. 12, capacitors other than the capacitor selected in the state change period are electrically disconnected from the power source, and thus such a general method cannot be adopted. A high voltage circuit must be adopted.

  Thus, in the comparative example, it is practically difficult to use an AC voltage for generating an electrostatic force from the viewpoint of timing control and high breakdown voltage.

  On the other hand, in the present embodiment, as described above, since the residual charge of the capacitor Cmn is not used, there is no possibility of malfunction due to the effect of leakage of the residual charge, and stable operation can be performed. It is.

  Further, in the present embodiment, even if AC driving is employed as shown in FIG. 10, the timing control as described above is not required at all, and the diagram is based on the general AC driving of the electrostatic force electrode. As shown in FIG. 10, since an AC electric potential having a reverse phase with reference to the reference potential can be applied to one electrode and the other electrode of the capacitor Cmn, AC driving can be easily realized.

  [Second Embodiment]

  FIG. 15 is an electric circuit diagram showing an optical switch array used in the optical switch system according to the second embodiment of the present invention. 15, elements that are the same as or correspond to those in FIG. 8 are given the same reference numerals, and redundant descriptions thereof are omitted.

  The optical switch system according to the present embodiment is different from the optical switch system according to the first embodiment in the optical switch array used in the present embodiment as shown in FIG. Instead of the current control switch MC3, four current control switches MC11 to MC14 are provided, and only a terminal C4 is added.

  By adopting such a configuration, in the present embodiment, while using a single current source I1, a positive Lorentz for generating a downward (−Z direction) Lorentz force in each coil Lmn. In addition to the force current, a reverse Lorentz force current for generating an upward (+ Z direction) Lorentz force can also flow. The upward Lorentz force is provided to increase the moving speed when the mirror 31 is moved from the lower position shown in FIG. 7 to the upper position shown in FIG.

  Next, FIG. 16 shows an example of a timing chart of voltages applied to the terminals C3, C4, VV1 to VV3, VH1 to VH3, IV1 to IV3, and IH1 to IH3 in FIG.

  Also in the present embodiment, the potential applied to the first and second potential supply terminals Vb and Va may be a DC potential as shown in FIG. 9 or an AC potential as shown in FIG. . Also in this example, when the voltage applied to each of these terminals is at a high level, the corresponding switch is turned on, and when the voltage is at a low level, the corresponding switch is turned off.

  The operation example shown in FIG. 16 corresponds to the operation example of the first embodiment shown in FIG. 11 described above. Similarly to the case of FIG. 11, FIG. 16 also shows the state holding period → the state change period of the optical switch in the first row and first column (release operation) → the state holding period → the state change period of the optical switch in the first row and first column (latch). Operation) → This is an example in which a state holding period is set.

  In FIG. 16, the period before time t31 is a state holding period. During this period, the terminals C3, C4, VV1 to VV3, VH1 to VH3, IV1 to IV3, and IH1 to IH3 are at a low level. In this state, a potential difference between the terminals Va and Vb (Vc in the case of FIG. 9, 2Vc in the case of FIG. 10) is applied to all the capacitors Cmn, and no current flows in all the coils Lmn. The mirror 31 of each optical switch is held at either the upper position shown in FIG. 6 or the lower position shown in FIG. Here, it is assumed that the mirror 31 of the optical switch in the first row and the first column is held at the lower position shown in FIG.

  At time t31, the state change period (release operation) of the optical switch in the first row and first column is started, the terminals VV1, VH1, IV1, and IH1 are set to the high level, and all other terminals remain at the low level. .

  At this time, one row selection signal interlocking switch M11ab, M12ab, M13ab of the first row is switched off, and the other M11aa, M12aa, M13aa of the first row is switched on, but the row selection signal interlocking switch of the other row is switched on. There is no change in the state. Also, one column selection signal interlocking switch M1ba of the first column is switched on, and the other column selection signal interlocking switch M1bb of the first column is switched off, but the state of the column selection signal interlocking switch of the other column is changed. There is no.

  Therefore, after time t31, the movable electrode 22d of the capacitor C11 in the first row and first column is connected to the first potential supply terminal Vb via the row selection signal interlocking switches M11aa and M1ba in the on state. For this reason, since the fixed electrode 41a of the capacitor C11 is directly connected to the first potential supply terminal Vb in the first place, a potential difference of zero is applied to the capacitor C11, and the bias voltage of the capacitor C11 becomes zero. As a result, the mirror 31 of the optical switch in the first row and first column starts to move to the upper position shown in FIG. 6 due to the stress (spring force) of the film in the region of the support plate 12b where the convex portions 24 are not provided. To do.

  After time t31, the terminal Va is connected to the movable electrode portion 22d of the other capacitor, and the potential difference between the terminals Va and Vb (Vc in the case of FIG. 9, 2Vc in the case of FIG. 10) is connected to the other capacitor. Is applied. Thus, according to the present embodiment, all the capacitors Cmn are not electrically disconnected from any one of the potential supply terminals Va and Vb even in the state change period.

  Thereafter, at time t32, the terminal C4 is set to the high level, and the Lorentz force current -I for generating the upward Lorentz force is supplied to the coil L11. In addition to the spring force in the region of the support plate 12b where the convex portion 24 is not provided, the upward Lorentz force also causes the mirror 31 of the optical switch in the first row and first column to move upward. Therefore, the moving speed of the mirror 31 upward is increased.

  After the mirror 31 of the optical switch in the first row and the first column moves to the upper position shown in FIG. 6, at time t33, the terminal C4 is set to the low level, and the Lorentz force current is stopped.

  Thereafter, at time t34, the terminals VV1, VH1, IV1, and IH1 are changed to the low level, thereby shifting to the state holding period.

  After this state holding period, at time t35, the state change period (latching operation) of the optical switch in the first row and first column is started. This latching operation is the same as in the first embodiment. Times t35 to t38 in FIG. 16 correspond to times t3 to t6 in FIG. 11, respectively. Therefore, the description of the latch operation is omitted here.

  According to the present embodiment, the same advantages as those of the first embodiment can be obtained. Further, according to the present embodiment, by using the upward Lorentz force, the moving speed for moving the mirror 31 from the lower position shown in FIG. 7 to the upper position shown in FIG. 6 can be increased, and vice versa. A single current source can be used without a separate current source for the directional Lorentz force.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments.

  For example, in each of the embodiments described above, a pair of column selection signal interlocking switches Mmba and Mmbb are provided for each column in common, but a pair of column selections that are complementarily turned on / off A signal interlocking switch may be provided on a one-to-one basis for each capacitor Cmn.

  In each of the above embodiments, the Lorentz force is used as the driving force other than the electrostatic force, but other driving force may be used. For example, a piezoelectric element may be provided instead of the Lorentz force current path 22d, and the driving force of the piezoelectric element may be used.

  Further, in each of the embodiments described above, the movable plate 12 has a cantilever structure, but in the present invention, for example, the movable part may have a double-supported beam structure.

  In addition, each of the above-described embodiments is an example in which the present invention is applied to an optical switch system. However, the present invention is not limited to the mirror 31, and the light-shielding film having a low light reflectance or a polarizing film having polarization characteristics is used. In addition, by mounting an optical thin film having optical wavelength filter characteristics, it can be applied to various optical devices such as an optical attenuator, a polarizer, and a wavelength selector.

It is a schematic block diagram which shows typically an example of the optical system provided with the optical switch array using the microactuator apparatus by the 1st Embodiment of this invention. FIG. 2 is a schematic plan view schematically showing the optical switch array in FIG. 1. FIG. 2 is a schematic plan view schematically showing one optical switch as a unit element of the optical switch array in FIG. 1. FIG. 4 is a schematic cross-sectional view along the line A-A ′ in FIG. 3. It is a figure which shows the pattern shape of Al film when the movable plate in FIG. 3 is seen from the top. FIG. 6 is a schematic cross-sectional view taken along the line B-B ′ in FIGS. 3 and 5 as viewed from the + X side in the −X axis direction, showing a state in which the mirror is held on the upper side. FIG. 6 is a schematic cross-sectional view taken along the line B-B ′ in FIGS. 3 and 5 as viewed from the + X side in the −X axis direction, showing a state in which the mirror is held on the lower side. FIG. 2 is an electric circuit diagram showing the optical switch array in FIG. 1. It is a figure which shows an example of the electric potential applied to the 1st and 2nd electric potential supply terminal in FIG. It is a figure which shows the other example of the electric potential applied to the 1st and 2nd electric potential supply terminal in FIG. It is a figure which shows an example of the timing chart of the voltage applied to each terminal of the optical switch array in FIG. It is an electric circuit diagram which shows the optical switch array by a comparative example. It is a figure which shows an example of the timing chart of the voltage applied to each terminal of the optical switch array shown in FIG. It is a figure which shows the example of an alternating current pulse. It is an electric circuit diagram which shows the optical switch array used with the optical switch system by the 2nd Embodiment of this invention. FIG. 16 is a diagram illustrating an example of a timing chart of voltages applied to each terminal of the optical switch array illustrated in FIG. 15.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical switch array 11 Board | substrate 12 Movable plate 22d Movable electrode 41a Fixed electrode 31 Mirror Cmn Capacitor Mmnaa, Mmnab Row selection signal interlocking switch Mnba, Mnbb Column selection signal interlocking switch

Claims (7)

A plurality of microactuators, and a drive circuit for driving the plurality of microactuators,
Each of the microactuators includes a movable part provided so as to be movable with respect to the fixed part, a first electrode part provided in the movable part, and the first electrode part provided in the fixed part, A second electrode part that can generate an electrostatic force by a voltage between and a driving force generation unit that is provided in the movable part and can generate a driving force other than the electrostatic force,
The drive circuit includes a plurality of pairs of row selection signal interlocking switches that are turned on / off in conjunction with a row selection signal that selects a row of the plurality of microactuators, and a column selection signal that selects a column of the plurality of microactuators. A plurality of pairs of column selection signal interlocking switches that are turned on and off in conjunction, and first and second potential supply terminals to which potentials are applied,
Each pair of row selection signal interlocking switches comprises two row selection signal interlocking switches that are turned on and off in a complementary manner,
Each pair of column selection signal interlocking switches includes two column selection signal interlocking switches that are complementarily turned on and off,
For each microactuator, one of the first and second electrode portions of the microactuator is electrically connected to the first potential supply terminal,
For each of the microactuators, the other electrode portion of the first and second electrode portions of the microactuator has the plurality of pairs regardless of the state of the row selection signal and the column selection signal. Of a total of four switches including a pair of row selection signal interlocking switches of the row selection signal interlocking switches and a pair of column selection signal interlocking switches of the plurality of pairs of column selection signal interlocking switches. Electrically connected to one of the first and second potential supply terminals via one or two switches in a state;
A microactuator device characterized by that. For each microactuator, each one end of two row selection signal interlocking switches (or column selection signal interlocking switches) of the four switches related to the microactuator is connected to the first and second of the microactuator. Electrically connected to the other electrode part of the electrode parts,
For each microactuator, the other end of one row selection signal interlocking switch (or column selection signal interlocking switch) of the four switches related to the microactuator and two column selections of the four switches Each end of the signal interlocking switch (or row selection signal interlocking switch) is electrically connected to each other,
For each microactuator, the other end of the other one of the four switches related to the microactuator is connected to the second potential supply terminal. Connected,
For each microactuator, the other end of one column selection signal interlocking switch (or row selection signal interlocking switch) of the four switches related to the microactuator is electrically connected to the first potential supply terminal. Connected,
For each of the microactuators, the other end of the other one of the four switches related to the microactuator is connected to the second potential supply terminal. Connected,
The microactuator device according to claim 1. Each pair of row selection signal interlocking switches (or column selection signal interlocking switches) is provided for each microactuator,
Each pair of column selection signal interlocking switches (or row selection signal interlocking switches) is provided in common for the column (or row) for each column (or row) of the plurality of microactuators.
The microactuator device according to claim 1 or 2, characterized in that   4. The microactuator device according to claim 1, wherein the driving force generation unit of each microactuator is a Lorentz force current path that is arranged in a magnetic field and generates a Lorentz force by energization. 5. .   5. The microactuator device according to claim 4, wherein the drive circuit includes a plurality of switches for selectively passing a current through the current path for the Lorentz force of the plurality of microactuators.   An optical switch system comprising: the microactuator device according to any one of claims 1 to 5; and a mirror provided on each of the movable parts of the plurality of microactuators.   An optical device comprising: the microactuator device according to any one of claims 1 to 5; and an optical element provided in each of the movable portions of the plurality of microactuators.

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