Patent Publication Number: US-6903494-B2

Title: Actuator optical fiber moving apparatus, and optical switch

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   The present application is a divisional of copending application Ser. No. 10/121,244 filed on Apr. 12, 2002. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to an actuator, an optical fiber moving apparatus driven by the actuator and an optical switch driven by the actuator, and more particularly, to an actuator having a rough moving means using a linear motor mechanism and a micro moving means using a thrust force obtained by converting electric energy into kinetic energy. 
   2. Description of the Related Art 
   Conventionally, there are known an actuator for executing inchworm operation and an actuator driven by impact drive by using, for example, a piezoelectric element, as actuators for obtaining a thrust force by converting electric energy into kinetic energy. 
   The operation principle of the inchworm operation will be described here with reference to FIG.  18 . An inchworm mechanism, which is composed of bodies  41  and  42  and piezoelectric elements  43 - 1  to  43 - 3  extendable in two-axes directions, is placed on a slide surface  44  (FIG.  18 ( a )). First, the piezoelectric element  43 - 1  extends in an upward direction orthogonal to a traveling direction by the voltage applied thereto, thereby the body  41  is lifted upward (FIG.  18 ( b )). Next, the piezoelectric element  43 - 2  extends in the traveling direction by the voltage applied thereto (FIG.  18 ( c )). After the piezoelectric element  43 - 2  extends to its full length, only the voltage applied to the piezoelectric element  43 - 1 , which has extended upward, is shut off, and the body  42 , which has been lifted upward, returns onto the slide surface  44  (FIG.  18 ( d )). 
   Next, the piezoelectric element  43 - 3  is extended in the upward direction orthogonal to the traveling direction by the voltage applied thereto, and the body  41  is lifted upward thereby (FIG.  18 ( e )). The voltage applied to the piezoelectric element  43 - 2 , which has extended in the traveling direction, is shut off, and the piezoelectric element  43 - 2  returns to its original length (FIG.  18 ( f )). Finally, the voltage applied to the piezoelectric element  43 - 3  is shut off, and the body  41 , which has been lifted upward, returns onto the slide surface  44  (FIG.  18 ( g )). As a result, the bodies  41  and  42  moves forward in the traveling direction by the amount of expansion of the piezoelectric element  43 - 2 . 
   The bodies  41  and  42  can be moved in an opposite direction by applying a voltage to the piezoelectric elements  43 - 1  and  43 - 2  in a reverse sequence. 
   Further, there is an impact drive mechanism acting as a micro actuator mechanism, in addition to the above inchworm mechanism. The operation principle of the impact drive mechanism will be also described with reference to FIG.  19 . The impact drive mechanism is arranged such that a body  51  is joined to a body  52  through a piezoelectric element  53 . The body  51  is pressed against a slide surface  54  by the pressure force F applied thereto (FIG.  19 ( a )). When the piezoelectric element  53  is extended as shown in the figure by the voltage abruptly applied thereto, the body  51  begins to slide left on the slide surface  54  because the inertial force of the body  51  overcomes the friction between the body  51  and the slide surface  54 . At the same time, the body  52  also moves right on the slide surface (FIG.  19 ( b )). Next, when the voltage applied to the piezoelectric element  53  is slowly released, the piezoelectric element  53  slowly returns to its original length. At this time, almost no inertial force is caused to both the bodies  51  and  52  because they have a small acceleration. Accordingly, the movement of the body  51  is prevented by the frictional force generated by the pressure force F between the body  51  and the slide surface  54 . As a result, the amount of movement of the impact drive mechanism, which was made when the piezoelectric element  53  extended at the beginning, is maintained, and the overall shape thereof returns to its original shape (FIG.  19 ( c )). The repetition of this operation permits the impact drive mechanism to move in the direction of the body  51 . 
   The impact drive mechanism can be moved in an opposite direction by slowly extending the piezoelectric element  53  at the beginning and then by abruptly contracting it when it extends to its full length. 
   The actuator disclosed in Japanese Unexamined Patent Publication (KOKAI) No. 4-360025 is known as an actuator using the above inchworm mechanism, and the actuator disclosed in Japanese Unexamined Patent Publication (KOKAI) No. 8-266073 is known as a conventional technology using the above impact drive mechanism. 
   A first problem of conventional actuators resides in that they cannot move a large distance at high velocity. This is because that only an inchworm mechanism and an impact drive mechanism are mounted thereon and these mechanisms are driven making use of the micro displacement of a piezoelectric element. That is, this type of the conventional actuators are arranged as an actuator specialized in micro drive and cannot move a large distance at high velocity. 
   A second problem of the conventional actuators resides in that they cannot be formed in a small size. This is because that when a conventional actuator is composed of only the micro actuators such as the inchworm mechanism and the impact drive mechanism, it is impossible to move it a long distance at high velocity. To cope with this problem, it is necessary to separately provide a high velocity drive mechanism such as a voice coil motor on the high velocity drive mechanism. As a result, the overall size of the conventional actuator is increased. 
   Therefore, when a mechanical type optical switch is composed of an optical fiber moving body using a conventional actuator, switching cannot be carried out at high velocity or a compact optical switch cannot be realized. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is a first object of the present invention for solving the problems of the conventional technology to provide a small actuator capable of moving at high velocity and making positional alignment at a pinpoint accuracy. A second object of the present invention is to provide an optical fiber moving body capable of moving at high velocity and making positional alignment at a pinpoint accuracy. A third object of the present invention is to provide a compact optical switch capable of being switched at high velocity and having a less connection loss. 
   To achieve the above-noted objects, the present invention adopts the following basic technical constitution. 
   The first aspect of the present invention is an actuator for moving a movable body by using a thrust force obtained by converting electric energy into kinetic energy, comprising:
     a first means for moving the movable body at high velocity for rough positioning of the movable body; and a second means for moving the movable body at low velocity for accurate positioning of the movable body.   

   In the second aspect of the present invention, the first means is a moving section of a linear motor having a moving section and a stationary section. 
   In the third aspect of the present invention, the moving section of the linear motor comprises any of a coil, a permanent magnet, and a conductive body, and the stationary section of the linear motor comprising any of a permanent magnet and a coil. 
   In the fourth aspect of the present invention, the second means comprises a piezoelectric element. 
   In the fifth aspect of the present invention, the second means is controlled by impact drive or inchworm drive using a piezoelectric element. 
   The sixth aspect of the present invention is an actuator for controlling positioning of a movable body, comprising:
     a main body of the movable body; a pair of piezoelectric elements secured to the main body; a pair of coils secured to the pair of piezoelectric elements; a guide for guiding the main body; and a plurality of magnets disposed along the guide.   

   In the seventh aspect of the present invention, the main body comprises a position detecting means for detecting a position thereof. 
   The eighth aspect of the present invention is an actuator for controlling positioning of a movable body, comprising:
     a main body of the movable body; a piezoelectric element secured to the main body; a coil secured to the piezoelectric element; a guide for guiding the main body; and a plurality of magnets disposed along the guide.   

   The ninth aspect of the present invention is an optical switch comprising: a board having a first and second main surfaces; a first movable body to which a first optical fiber is secured; a first piezoelectric element secured to the first movable body; a first coil secured to the first piezoelectric element; a first guide, formed on the first surface, for guiding the first movable body; a plurality of permanent magnets disposed along the first guide; a second movable body to which a first optical fiber is secured; a second piezoelectric element secured to the second movable body; a second coil secured to the second piezoelectric element; a second guide, formed on the second surface and provided orthogonally to the first guide, for guiding the second movable body; a plurality of permanent magnets disposed along the second guide; and
     a through hole formed at an intersection of the first guide and second guide provided on the board.   

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG.  1 ( a ) and FIG.  1 ( b ) are a plan view and a side elevational view of an actuator of a first embodiment of the present invention, respectively; 
     FIG.  1 ( c ) is a block diagram of the first embodiment of the present invention. 
       FIG. 2  is a plan view of the actuator of the first embodiment of the present invention mounted on guides; 
     FIGS.  3 ( a ) to ( c ) are views explaining operations of the actuator of the first embodiment of the present invention; 
     FIGS.  4 ( a ) to ( c ) are views explaining operations of the actuator of the first embodiment of the present invention; 
     FIGS.  5 ( a ) to ( d ) are views explaining other operations of the actuator of the first embodiment of the present invention; 
     FIG.  6 ( a ) and FIG.  6 ( b ) are a plan view and a side elevational view of an actuator of a second embodiment of the present invention, respectively; 
       FIG. 7  is a side elevational view of an actuator of a third embodiment of the present invention; 
       FIG. 8  is a side elevational view of an actuator of a fourth embodiment of the present invention; 
     FIG.  9 ( a ) is a plan view of an actuator of a fifth embodiment of the present invention; 
     FIG.  9 ( b ) is a side elevational view of the actuator; 
       FIG. 10  is a plan view of the actuator of the fifth embodiment of the present invention mounted on guides; 
     FIG.  11 ( a ) and FIG.  11 ( b ) are a plan view and a side elevational view of an actuator of a sixth embodiment of the present invention, respectively; 
       FIG. 12  is a plan view of the actuator of the sixth embodiment of the present invention mounted on guides; 
       FIG. 13  is a perspective view showing a mechanical type optical switch of an example of the present invention; 
     FIG.  14 ( a ) is a partial enlarged view of the mechanical type optical switch shown in  FIG. 13 ; 
     FIG.  14 ( b ) is a sectional view of a slider; 
       FIG. 15  is a schematic plan view of the mechanical type optical switch of the example of the present invention; 
       FIG. 16  is a view explaining an operation of the mechanical type optical switch of the example of the present invention; 
     FIG.  17 ( a ) and FIG.  17 ( b ) are drawings explaining the operation of the mechanical type optical switch of the example of the present invention; 
     FIG.  18 ( a ) to FIG.  18 ( g ) are drawings explaining the operation principle of an inchworm drive system; and 
     FIG.  19 ( a ) to FIG.  19 ( c ) are drawings explaining the operation principle of an impact drive system. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Next, embodiments of the present invention will be described below in detail with reference to the drawings. 
   (First Embodiment) 
   FIG.  1 ( a ) and FIG.  1 ( b ) are a plan view and a side elevational view of an actuator of a first embodiment of the present invention, respectively. As shown in FIG.  1 ( a ) and FIG.  1 ( b ), the actuator of the first embodiment is composed of a moving body  10  in which piezoelectric elements  13  and  13 ′ and coils  12  and  12 ′ are joined to both the sides of the moving member  10 . Further, as shown in  FIG. 2 , the moving body  10  is inserted between guides  14  and can move along the guides  14 . Further, a permanent magnet  15  is disposed along one of the guides  14  so that S-poles and N-poles alternately appear along the guide  14 . 
   Next, an operation of the actuator of the first embodiment will be described. First, the high velocity operation (rough operation) of the actuator will be described with reference to FIG.  3 . As shown in  FIG. 3 , the high velocity operation of the actuator is carried out by a principle similar to that of a so-called magnetic type linear motor. The coils  12  and  12 ′, which are joined to the main body  11  through the piezoelectric elements  13  and  13 ′, are energized, and magnetic fields are generated in the coils  12  and  12 ′ such that the coils  12  and  12 ′ near to an S-pole permanent magnet  15  and an N-pole permanent magnet  15  are set to an N-pole and an S-pole, respectively. An attractive force A is generated by the magnetic fields generated in the coils  12  and  12 ′ between the coils and the permanent magnet  15  disposed along the guide  14 . When the moving body  10  is moved by the attractive force A one block of the permanent magnet  15 , the coils  12  and  12 ′ are energized at opposite polarity, thereby a new attractive force A′ is generated. Attractive forces A, A′, and A″ are generated by switching the energization of the coils  12  and  12 ′, thereby a thrust force for moving the moving body  10  at high velocity can be obtained. 
   Next, the micro operation of the actuator will be described with reference to FIG.  4 . The micro operation of the actuator of the first embodiment shown in  FIG. 4  is carried out by a principle similar to that of so-called impact drive. The coils  12  and  12 ′, which are joined to the main body  11  through the piezoelectric elements  13  and  13 ′, are energized, and magnetic fields are generated in the coils  12  and  12 ′ such that the coils  12  and  12 ′ near to an S-pole permanent magnet  15  and an N-pole permanent magnet  15  are set to an S-pole and an N-pole, respectively. Attractive forces A and A′ are generated by the magnetic fields generated in the coils  12  and  12 ′ between the coils and the permanent magnets  15  disposed along the guide  14 , respectively. A pressure force F for pressing the main body  11  against the guide  14  can be obtained by the attractive forces A and A′. When a voltage is abruptly applied to the piezoelectric element  13  in this state, the piezoelectric element  13  extends. Thus, the pressure force F causes the inertial force of the main body  11  to overcome the frictional force generated between the main body  11  and the guide  14 , and the main body  11  begins to move in a right direction on the slide surface. At the same time, the coil  12  also moves in a left direction left on the slide surface. 
   Next, when the voltage applied to the piezoelectric element  13  is slowly released, the piezoelectric element  13  slowly returns to its original length. At this time, almost no inertial force is generated to both the main body  11  and the coil  12  because they have a small acceleration. Accordingly, the movement of the main body  11  is prevented by the frictional force generated between the main body  11  and the guide  14  by the pressure force F. 
   As a result, the amount of movement of the actuator, which is generated when the piezoelectric element  53  extended at the beginning, is maintained, and the overall shape of the actuator returns to its original shape. The main body  11  can be moved in the direction of the coil  12 ′ by repeating this operation. 
   The actuator can be moved in an opposite direction by previously extending the piezoelectric element  13  slowly and then contracting it abruptly. Further, an operation similar to that described above can be carried out by using the piezoelectric element  13 ′ disposed on the opposite side. 
   As described above, in the actuator of the first embodiment, magnetic type linear motor drive and impact drive can be realized by the single moving body, whereby there can be provided an actuator having the characteristics of both high velocity movement and positional alignment of a pinpoint accuracy. Further, a miniature actuator can be realized because the coils, which are used for the magnetic type linear motor drive, are integrated with the inertial body necessary to the impact drive as well as the magnetic force generated by the coils is used to obtain the pressure force necessary for the impact drive. 
   (Other Drive Method of the Actuator of the First Embodiment) 
   The method for micro driving the actuator of the first embodiment by the impact drive was described above. However, the actuator of the first embodiment can be also driven by an inchworm system. The inchworm drive system will be described with reference to FIG.  5 . The coil  12  is energized and a magnetic field is generated in the coil  12  such that the portion thereof facing the N-pole permanent magnet  15  is set to an S-pole. An attractive force A is generated between the coil  12  and the N-pole permanent magnet  15  disposed along the guide  14  by the magnetic field generated in the coil  12 . Further, the coil  12 ′ disposed on the opposite side is energized and a magnetic field is generated in the coil  12 ′ such that the portion thereof facing the S-pole permanent magnet  15  is set to an S-pole. A repulsive force R is generated by the magnetic field generated in the coil  12  between the coil  12 ′ and the permanent magnet  15  disposed along the guide  14 . In this state, a voltage is applied to the piezoelectric elements  13 ′ and  13  so as to extend them. At this time, the main body  11  and the coil  12 ′ are moved in the right direction on the slide surface by the amounts of extension of the piezoelectric elements  13  and  13 ′ while the coil  12  held by the attractive force A remains stationary. Next, the coil  12  is energized on the contrary, and a magnetic force is generated thereby in the coil  12  so as to generate a repulsive force R between the coil  12  and the permanent magnet  15 . Further, the coil  12 ′ disposed on the opposite side is energized, and a magnetic field is generated in the coil  12 ′ so as to generate an attractive force A between the coil  12 ′ and the permanent magnet  15 . In this state, the voltage applied to the piezoelectric elements  13 ′ and  13  is released, and they are contracted to their original length. At this time, the main body  11  and the coil  12  are moved in the right direction on the sheet surface by the amounts of contraction of the piezoelectric elements  13  and  13 ′ while the coil  12 ′ held by the attractive force A remains stationary. As a result, the moving body can be moved by the amounts of extension of the two piezoelectric elements. 
   Note that, in the inchworm drive of the first embodiment, the coils may be simply deenergized so as to remove the magnetic field generated therein in place of generating the repulsive force by the coils. 
   FIG.  1 ( c ) is a block diagram of the first embodiment of the present invention. In FIG.  1 ( c ), the numeral  100  denotes a driving means for controlling the movable body  10  by impact drive or inchworm drive using the piezoelectric element  13  or/and  13 ′. 
   (Second Embodiment) 
   FIGS.  6 ( a ) and  6 ( b ) are a plan view and a side elevational view of an actuator of a second embodiment of the present invention. In the actuator of the second embodiment, a coil  12  and a piezoelectric element  13  are disposed on only one side of a main body  11  as shown in  FIG. 6 , while the coils and the piezoelectric elements are disposed on both the side of the main body  11  in the first embodiment. 
   The actuator of the second embodiment is driven at high velocity similarly to the fist embodiment. That is, an attractive force is generated between a permanent magnet disposed along a guide and a coil  12  by sequentially inverting the polarity of a current flowing in the coil  12 , thereby a thrust force is obtained. When the actuator is micro moved, first, a current is supplied to the coil  12  to generate an attractive force between the coil  12  and the permanent magnet, and the piezoelectric element  13  is extended in this state, similarly to the inchworm drive. With this operation, the main body  11  is moved. Next, the current having been supplied to the coil  12  is shut off, and the voltage having been applied to the piezoelectric element  13  is slowly reduced, similarly to the impact drive system. At this time, the main body  11  remains stationary because a frictional force acts between the coil  12  and the guide, and only the coil  12  is moved toward the main body  11 . The main body  11  can be moved in a direction opposite to the coil  12  by repeating this operation. 
   To move the main body  11  in an opposite direction, the sequence of the above operation is reversed so that the piezoelectric element  13  is slowly extended without supplying a current to the coil  12  and the voltage having been applied to the piezoelectric element  13  is released while restricting the movement of the coil  12  by supplying a current thereto. 
   (Third Embodiment) 
     FIG. 7  is a side elevational view of an actuator of a third embodiment of the present invention. In the first and second embodiments of the present invention, the coil(s) and the piezoelectric element(s) are disposed to the outside of the main body  11 . In a moving body  10  of the third embodiment, however, two coils  12  and  12 ′ are disposed in the inside of a main body  11  and connected to the wall surfaces of the main body  11  through piezoelectric elements  13  and  13 ′, respectively, as shown in FIG.  7 . 
   The actuator of the third embodiment is driven at high velocity, similarly to the fist embodiment. That is, a thrust force is obtained by generating an attractive force between a permanent magnet disposed along a guide and the coil  12  by sequentially inverting the polarity of a current flowing in the coil  12 . Further, when the actuator is micro moved in a right direction on the slide surface, first, the piezoelectric element  13  is extended in a state that the attractive force is applied to the coil  12 . Next, the current supplied to the coil  12  is shut off, and an attractive force is applied to the coil  12 ′. Then, the voltage having been applied to the piezoelectric element  13  is released in this state. After the current having been supplied to the coil  12 ′ is shut off, the above-mentioned operations are repeated. Further, when the moving body  10  is moved in a left direction on the slide surface, the operations of the coils  12  and  12 ′ and the piezoelectric elements  13  and  13 ′ are inverted from the above operations thereof. 
   (Fourth Embodiment) 
     FIG. 8  is a side elevational view showing an actuator of a fourth embodiment of the present invention. In the third embodiment of the present invention, the two coils and the two piezoelectric elements are disposed in the inside of the main body  11 . In the fourth embodiment, however, a single coil  12  is disposed in the inside of a main body  11 , and both the ends of the coil  12  are connected to the wall surfaces of the main body  11  through piezoelectric elements  13  and  13 ′, as shown in FIG.  8 . 
   The actuator of the fourth embodiment is driven at high velocity, similarly to the fist embodiment. That is, a thrust force is obtained by generating an attractive force between a permanent magnet disposed along a guide and the coil  12  by sequentially inverting the polarity of a current flowing in the coil  12 . When the actuator is micro moved in a right direction on the slide surface, a current is supplied to the coil  12  so as to generate an attractive force between the coil  12  and the permanent magnet, and the piezoelectric element  13 ′ is extended in this state, similarly to the inchworm drive. With this operation, the main body  11  is moved in the right direction. Next, the current supplied to the coil  12  is shut off, and the piezoelectric element  13  is extended and the piezoelectric element  13 ′ is returned to its original length at the same time. Then, a current is supplied to the coil  12  so as to generate an attractive force between the coil  12 ′ and the permanent magnet, and the piezoelectric element  13 ′ is extended again and the piezoelectric element  13  is returned to its original length in this state. Thereafter, the above-noted operations are performed repeatedly. 
   (Fifth Embodiment) 
   FIGS.  9 ( a ) and  9 ( b ) are a plan view and a side elevational view of an actuator of a fifth embodiment of the present invention. While the actuators of the first to fourth embodiments of the present invention disposes the coil(s) on the moving body, in the fifth embodiment, a permanent magnet is joined to a moving body. That is, as shown in FIGS.  9 ( a ) and ( b ), a moving body  10  is arranged such that permanent magnets  16  and  16 ′ are connected to the right and left sides of a main body  11  through piezoelectric elements  13  and  13 ′. Then, as shown in  FIG. 10 , the moving body  10  of the fifth embodiment is disposed between guides  14 . Additionally, coils  17  which constitute a linear motor together with permanent magnets  16  and  16 ′ are disposed along one of the guides  14 . 
   In this fifth embodiment, the permanent magnet of the first embodiment is replaced with the coils thereof, and the operation of the fifth embodiment is the same as that of the first embodiment. Thus, the description of operation of the fifth embodiment is omitted. 
   While the fifth embodiment is arranged by replacing the coils of the first embodiment with the permanent magnets thereof, the permanent magnet of the second to fourth embodiments may be mounted on the moving body side by applying the same replacement thereto. 
   (Sixth Embodiment) 
   FIGS.  11 ( a ) and  11 ( b ) are a plan view and a side elevational view of an actuator of a sixth embodiment of the present invention. While the actuators of the first to fifth embodiments described above are moved at high velocity by the magnetic type linear motor, the actuator of the sixth embodiment is moved at high velocity by an induction type linear motor. Accordingly, in the sixth embodiment, electric conductors  18  and  18 ′ are connected to the front and back side surfaces of a main body  11  through piezoelectric elements  13  and  13 ′, as shown in FIG.  11 . The electric conductors  18  and  18 ′ carry out a function as an inertial body when a moving body  10  of the sixth embodiment is driven by an impact drive system. Then, as shown in  FIG. 12 , the moving body  10  of the sixth embodiment is disposed between guides  14 , and a coil  19  is disposed along the outside of one of the guides  14  to generate a moving magnetic field in the guides  14 . 
   Next, an operation of the actuator of the sixth embodiment will be described. When the actuator is moved at high velocity, a moving magnetic field, which moves in a direction where the moving body  10  is moved, is generated by the coils  19 . With this operation, the electric conductor  18  is subjected to a thrust force and moved at high velocity in the direction where the magnetic field moves. Further, when the moving body  10  is micro moved in a right direction on the slide surface, first, the piezoelectric element  13  is extended abruptly. Then, the piezoelectric element  13  is slowly contracted as well as the piezoelectric element  13 ′ is extended slowly. At this time, the main body  11  remains stationary due to the frictional force between the main body  11  and the guides  14 . Next, the piezoelectric element  13  is extended abruptly as well as the piezoelectric element  13 ′ is contracted abruptly. With this operation, the main body  11  is moved in the right direction. The moving body  10  can be moved in the right direction on the slide surface by repeating the above operation. 
   The moving body  10  can be moved in an opposite direction by replacing the operation of the piezoelectric element  13  with that of the piezoelectric element  13 ′. 
   In the first and second embodiments of the present invention, the permanent magnet and the coil(s) are disposed along the guide in one row with respect to the moving body. However, it is possible to dispose a plurality of rows of permanent magnets and coils by disposing them along the guide where they were not disposed in the first and second embodiments or by disposing them on upper and lower portions of the sheet surface. 
   Further, the pressure force applied to the main body when it is impact driven is obtained from the magnetic force generated by the coil(s) or the magnetic body provided with the moving body. However, a different pressure application means may be provided and used. 
   EXAMPLE 
   Next, an example of the present invention will be described below in detail with reference to FIGS.  13  and  14 ( a ) and  14 ( b ). 
     FIG. 13  is a perspective view showing the example of the present invention. In the example of the present invention, any of the actuators shown in the embodiments is applied to a mechanical type optical switch. As shown in  FIG. 13 , in a mechanical type optical switch  20  of the present invention, optical fibers  21  are inserted into sliders  22  and fixed therein so that they can linearly move integrally with the sliders  22 . A standard optical fiber having a diameter of 125 μm is used as each optical fiber  21 . The sliders  22  slide along slide guides  24  formed on a board  23  having a thickness of 10 mm. Each 100 pieces of the slide guides  24  are formed on the front and back surfaces of the board  23  so as to be orthogonal to each other. The number of the slide guides  24  is determined by the scale of optical switches, and 100×100 sets of optical switches are provided in this example. A permanent magnet is disposed such that S-poles and N-poles thereof are alternately arranged along the slide guide  24 . 
   Next, the sliders  22  will be described in detail with reference to FIG.  14 ( a ) and FIG.  14 ( b ). FIG.  14 ( a ) is a partial enlarged view of the mechanical type optical switch of  FIG. 13  (in FIG.  14 ( a ), a part of the board is omitted so that the figure can be understood easily), and FIG.  14 ( b ) is a sectional view of the slider  22 . The slider  22  is composed of a slider main body  31  into which an optical fiber  21  is inserted, piezoelectric elements  32  and  32 ′ secured to the slider main body  31 , and coils  33  and  33 ′ secured to the piezoelectric elements  32  and  32 ′. The slider  22  is arranged as a micro actuator that is impact driven. The slider main body  31  has a size of 5 mm that is approximately half the thickness of the board  23  in the height direction thereof in which the optical fiber is inserted. Further, the slider main body  31  has a length of 4 mm and a width of 2 mm. Stainless steel is used as a material of the slider main body  31 . The end surface of the optical fiber  21  is flush with the bottom surface of the slider main body  31  or is slightly retracted therefrom (preferably 25 μm or less to suppress an insertion loss to a low level). The cladding thickness of the optical fiber  21  at the portion thereof inserted into the slider main body  31  may be set larger than that of the other portion thereof. 
   Each coil has a size half that of the slider main body  31  and is formed in an approximately rectangular prism of 3 mm×3.3 mm×1.8 mm. Further, a copper wire is used as a winding material of each coil. A coil wiring  331  is taken out to the outside so as to travel along an optical fiber  21 . A PZT laminated type piezoelectric element having a length of 5 mm and a cross section of 2 mm×1 mm is used as each piezoelectric element. A magnetic sensor  34  is attached to the slider main body  31  so as to detect the position of the micro actuator. 
   As shown in FIG.  14 ( b ), a through hole is formed through the slider main body  31 , and the optical fiber  21  is inserted therethrough, and bonded and secured therein. The coil  33  is bonded and secured to the slider main body  31  through the piezoelectric element  32 . The coil  33  and the piezoelectric element  32  are arranged independently of a slide guide  24  so that they are not in contact therewith. A voltage must be applied to the piezoelectric element  32  in order to impact drive the slider  22 , and a piezoelectric element wiring  321  for this purpose is taken out to the outside so as to travel along the optical fiber  21 . 
   The position of the micro actuator is detected by the magnetic sensor  34  attached to the slider main body  31 . The magnetic sensor  34  is attached to the slider main body  31  such that the head portion thereof extends off the slider main body  31 . A magnetized pattern  35  is provided on the board  23  so as to face the magnetic sensor  34  attached to the slider main body  31 . A magnetic sensor wiring  341  from the magnetic sensor  34  is also taken out to the outside so as to travel along the optical fiber  21 . 
   As to the arrangement of the example, finally, the size of the mechanical type optical switch in its entirety will be described. The number of the guides along which the sliders travel are set to 100 pieces, and the guides are disposed at pitches of 4 mm (in  FIG. 1 , the intervals between the guides are increased and the number of the guides is omitted for easy understanding). The boards  13  is formed in a shape having a size of 408 mm×408 mm×10 mm thick. 
   (Operation of the Example) 
   Next, an operation of the mechanical type optical switch of the example of the present invention will be described. In the mechanical type optical switch  20  shown in  FIG. 13 , the optical fibers drawn onto the front and back surfaces of the board  23  are moved to a position where the fiber cores thereof are aligned with each other, thereby they are switched and connected to each other.  FIG. 15  is a plan view showing the schematic state of the above operation (in the figure, a step formed in each slide guide  24  is omitted to simplify the figure). In  FIG. 15 , sliders  22  and  22   a  on the front and back surfaces of the board  23  are moved in a white arrow direction and a black arrow direction, respectively, and the connection of optical fibers to each other is completed by aligning the cores thereof within a through hole  26  formed through the boards  23 .  FIG. 16  is a sectional view showing the sliders  22  and  22   a  when the cores of the optical fibers are aligned with each other. The slider main body  31  of the slider  22  on the front surface of the board  23  reciprocates in a right and left direction on the sheet surface with the slide surface  311  thereof in contact with the guide surface of the board  23 . In contrast, the slider main body  31   a  of the sliders  22   a  on the back surface of the board  23  reciprocates in a vertical direction on the sheet surface with the slide surface  311   a  thereof in contact with the guide surface of the board  23 . The guide surface with which the slide surface  311  comes into contact is a guide surface  36  shown in FIG.  14 ( a ). In this state, the optical fiber  21  drawn onto the front surface side is aligned with the optical fiber  21   a  drawn from the back surface side so that they are connected to each other. 
   Subsequently, the operation of the mechanical type optical switch will be described in more detail. First, in the mechanical type optical switch  20  shown in  FIG. 15 , when a command for joining the optical fiber of the slider  22  to the optical fiber of the slider  22   a  is supplied to a control system (not shown) first, coils  33  and  33 ′ are energized to drive the sliders to which the optical fibers to be switched are attached. At this time, the respective sliders perform an electromagnetic type linear motor operation while the polarities of the energized coils are switched, as shown in FIG.  3 . At this time, the sliders  20  and  22   a  move long distances at high velocity along the slide guides  24  on the boards  23 . They complete the movement in about 20 ms at a maximum. As shown in  FIG. 15 , when the sliders  22  are roughly moved to the column of the slider  22   a  and the slider  22   a  are roughly moved to the row of the sliders  22  by the linear motor operation, the sliders  22  is aligned with the slider  22   a  by the impact drive micro actuators formed in the sliders  22   a  in an order of submicron. This impact drive is carried out in such a manner that an attractive force is generated between the coils  33  and  33 ′ and a permanent magnets, respectively, by supplying a current to the coils  33  and  33 ′ and the pressure force of the slider main body  31  against the guide surfaces of the board is obtained thereby. However, since the operation principle of the impact drive operation of the sliders of the example is as described above with reference to  FIG. 4 , the detailed description thereof is omitted. 
   The operation performance of the impact drive in this example will be described with reference to FIG.  17 . Note that only one set of a coil and a piezoelectric element is used in FIG.  17  and the coil is arranged as a simple inertial body for the purpose of simplification. First, a calculation method will be briefly described. In this example, a PZT piezoelectric element is used as the piezoelectric elements. When the PZT piezoelectric element extends by a voltage applied thereto, a slider moves in an amount of movement (ΔX 1 ). The slider, the PZT piezoelectric element and the inertial body slide and move as a single rigid body in an amount of movement (X). Then, the total of the amount of movement (ΔX 1 ) and the amount of movement (X) is defined as a total amount of movement per 1 pulse. A time passed in the operation of the one pulse is defined as one cycle (T), and a feed velocity is defined as a product of the total amount of movement and (1/T). 
   Next, equations will be shown in detail. Kinetic equations when a voltage is applied to the PZT piezoelectric element and it generates an extension force (P) are established as to the slider (mass: M 1 ), the inertial body (mass: M 2 ), and the piezoelectric element (mass: Mp). 
   When the coefficient of static friction of the slider at this time is represented by μ0, a frictional force (μ0F) is generated in the slider by a pressure force F as shown in the following equations (1) and (2).
 
 P −μ0 ·F =α 1 ·( M   1 +0.5 Mp )  (1)
 
 P =α 2 ·( M   2 +0.5 Mp )  (2)
 
   The accelerations (α 1  and α 2 ) of the slider and the inertial body are determined from the equations (1) and (2), respectively. The amount of extension (ΔX) of the piezoelectric element is the total of the moving amount (ΔX 1 ) of the slider and the moving amount (ΔX 2 ) of the inertial body. Thus, the following equation (3) is obtained. 
    Δ X=ΔX   1 +Δ X   2   (3) 
   Further, the moving amounts of the slider and the inertial body are determined by the following equations (4).
 
Δ X   1 =0.5*(0.5*α 1 )*Δ t ^ 2 
 
Δ X   2 =0.5*(0.5*α 2 )*Δ t ^ 2   (4)
 
   Accordingly, the moving amount (ΔX 1 ) of the slider can be calculated using the equations (1) to (4). It is contemplated here that the accelerations α continuously changes during the time Δt. In this calculation, the accelerations are multiplied by 0.5 and linearly approximated. 
   Next, the moving amount of the overall system when it slides as a rigid body is determined. First, the initial velocities of the respective mass systems are determined by the following equations (5).
 
 V   01 =(0.5·α 1 )·Δ t 
 
 V   02 =(0.5·α 2 )·Δ t   (5)
 
   Accordingly, the momenta of the respective mass systems are determined by the following equations (6).
 
 MV   1 = V   01 ·( M   1 +0.5 ·Mp )
 
 MV   2 = V   02 ·( M   2 +0.5 Mp )  (6)
 
   An entire momentum is represented by the following equation from the law of conservation of momentum, thereby the initial velocity (V 0 ) when an overall system begins to move (V 0 ) is determined by the following equation (7).
 
( M   1 + M   2 + Mp )· V   0 = MV   1 − MV   2   (7)
 
   The kinetic energy (E) at that time is determined by the following equation (8) using the initial velocity determined by the equation (7).
 
 E =0.5·( M   1 + M   2 + Mp )· V   0 ^ 2   (8)
 
   The sliding amount (X) of the overall system is determined by the following equation (9) assuming that the above energy has been entirely consumed as a friction loss.
 
 X=E/μF   (9)
 
where, μ shows a coefficient of dynamic friction.
 
   The acceleration (a) when the overall system slides is represented by the by the following equation (10).
 
( M   1 + M   2 + Mp )· a=μF   (10)
 
   Thus, the period of time (ts) passed from the time the overall system begins to move to the time it stops is represented by the following equation (11).
 
 ts=V   0 / a   (11)
 
   Further, a period of time necessary to the feed of one pulse, that is, the cycle (T) is the total of the time (Δt) necessary to the expansion of the PZT piezoelectric element, the time (ts) during which the overall system slides as the rigid body, and further the time (tb) necessary for the contraction of the PZT piezoelectric element, as shown in by the following equation (12). The time (tb) necessary for the contraction of the PZT piezoelectric element is determined based on the assumption that the inertial force generated at that time is sufficiently small with respect to the frictional force (μ0F).
 
 T=Δt+ts+tb   (12)
 
   A feed velocity (Vs) is determined from a total moving amount and the cycle (T), as shown in the following equation (13).
 
 Vs =(Δ X   1 + X )/ T   (13)
 
   When the data of the specification of the actual piezoelectric elements, the mass of the sliders, and the like are input to the above equations, the moving amount per one path of the overall system and the moving velocity thereof are determined as shown below. 
   Moving amount per one pulse (resolution): 1 nm 
   Moving velocity: 10 μs/sec 
   The positions reached by both the rough movement carried out by the linear motor and the micro movement carried out by the impact drive are detected by the magnetic sensor  34  mounted on the slider main body  31 . Since the magnetized pattern  35  is formed on the board  23  as described above, the position of the slider  22  itself can be determined by reading the magnetized pattern  35 . 
   Note that it is required to align the optical axes of optical fibers at an accuracy of submicron. Therefore, the optical axes can be aligned with each other at a pinpoint accuracy by recording a magnetized pattern that corresponds to an optimum slider position as an address when the optical axes are adjusted. Further, it is also possible to align the optical axes periodically when optical fibers are not used and to update the optimum address, in addition to that they are subjected to alignment when an apparatus is shipped. 
   As described above in detail, since the actuator of the present invention includes a high velocity self-moving means and a self-moving means of micro pitch, there can be realized a common actuator that can move a large distance at high velocity as well as move at a pinpoint accuracy. According to the present invention, an actuator having the above characteristics can be realized compactly. Further, when an optical switch is arranged using the actuators according to the present invention, a mechanical type optical switch capable of performing high velocity switching with a less amount of optical loss can be realized compactly.