Abstract:
An ultrasonic motor has a vibrating body polarized in a given direction. The vibrating body comprises a first piezoelectric body and a second piezoelectric body laminated to the first piezoelectric body in a preselected direction generally parallel to the polarized direction. Each of the first piezoelectric body and the second piezoelectric body has a first polarized portion and a second polarized portion. The first polarized portion of the first piezoelectric body is aligned in the preselected direction with the second polarized portion of the second piezoelectric body. The second polarized portion of the first piezoelectric body is aligned in the preselected direction with the first polarized portion of the second piezoelectric body. A movable member is frictionally driven by a combination of a stretching vibration and a bending vibration generated by applying a driving signal to the first polarized portions of the first and second piezoelectric bodies or to the second polarized portions of the first and second piezoelectric bodies.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an ultrasonic motor in which piezoelectric vibrators are laminated in a body in the longitudinal direction in parallel to its polarizing direction land more particularly to an improvement of an ultrasonic motor utilizing longitudinal vibration of the piezoelectric vibrators and an electronic apparatus equipped with the ultrasonic motor. 
     An ultrasonic motor utilizing vibration of piezoelectric vibrators is drawing attention lately in the field of micromotors. 
     An ultrasonic motor utilizing stretching vibration and bending vibration of rectangular piezoelectric vibrators (dual-mode vibrator) in particular is used in various uses because it is capable of moving an object linearly or rotatably by combined vibration of those two vibrations. An ultrasonic motor of a type in which piezoelectric bodies are layered is also used a high output is required (see Japanese Patent Laid-Open No. Hei. 7-184382). 
     FIG. 16 shows an ultrasonic motor of a type in which rectangular plate-like piezoelectric bodies are layered. A basic vibrator of the ultrasonic motor comprises piezoelectric bodies  61 ,  62 ,  63 ,  64 ,  65  and  66  which are polarized in a predetermined manner so as to vibrate in the dual mode and are layered in the polarizing direction, output fetching members  71 ,  72 ,  73 ,  74 ,  75  and  76  provided on edge portions  61   a,    62   a,    63   a,    64   a,    65   a  and  66   a  provided in the direction vertical to the polarizing direction of the piezoelectric bodies  61  through  66 , and electrodes (not shown) provided on both sides of the piezoelectric bodies  61  through  66 . The six piezoelectric vibrators, i.e., the piezoelectric bodies of two rows arrayed in the horizontal direction and stacked in three layers in the vertical direction, are held by coupling means  67 ,  68  and  69 . 
     When voltage is applied from the electrodes, the respective piezoelectric bodies  61  through  66  vibrate in the dual modes and the combined vibration thereof is transmitted to the respective output fetching members  71  through  76  to move an object abutting with the output fetching members  71  through  76 . 
     It is designed to obtain a high output by taking out the output from the plurality of piezoelectric bodies  61  through  66 . 
     However, because the respective piezoelectric bodies  61  through  66  are fixed merely by part thereof by the coupling means  67  through  69 , the vibrating direction may vary among the respective piezoelectric bodies  61  through  66  in the ultrasonic motor described above. It also has had a technological problem that because the vibration of the fixed parts of the piezoelectric bodies  61  through  66  is suppressed, it causes vibration loss and the output cannot be taken out effectively. 
     Still more, it is not preferable to use the above-mentioned coupling means  67  through  69  as the separate members for fixing the respective piezoelectric bodies  61  through  66  because it enlarges and complicates the whole structure of the motor and because the production process thereof is complicated by adding the step for mounting the coupling means  67  through  69 . 
     Meanwhile, although the above-mentioned problem may be solved by laminating the piezoelectric bodies in a body in the polarizing direction and by taking out the output only by the piezoelectric transverse effect, there is a technological problem that a high output cannot be obtained because the electric-mechanic coupling coefficient of the piezoelectric transverse effect is small. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to solve the above-mentioned technological problems by providing an ultrasonic motor whose vibration loss is suppressed, whose structure is miniaturized, whose production process is simplified and which is capable of utilizing electrical energy efficiently. 
     It is another object of the present invention to provide an electronic apparatus equipped with an ultrasonic motor. 
     In order to achieve the above-mentioned objectives, an inventive ultrasonic motor comprises a first piezoelectric body having a first polarized portion excited when voltage is applied and a second piezoelectric body that is laminated with the first piezoelectric body in the longitudinal direction parallel to the polarizing direction. The second piezoelectric body has a first polarized portion at a position separated from the first polarized portion of the first piezoelectric body in the transverse direction vertical to the polarizing direction, and moves a moving body by stretching vibration and bending vibration caused by vibrations of the first polarized portion of the first piezoelectric body and the first polarized portion of the second piezoelectric body in the longitudinal direction. 
     The polarized portion of the first piezoelectric body and the polarized portion of the second piezoelectric body excite in the vertical and horizontal directions, respectively. The stretching vibration is then produced when the respective vibrations in the longitudinal direction overlap and the bending vibration is produced from the implication between the transverse vibrations and the stretching vibration therearound. The moving body is then moved by elliptic vibration obtained by combining the stretching vibration and the bending vibration. 
     Further, the piezoelectric vibrators are laminated in a body without using fixing means, so that the vibration is not suppressed and the vibrating direction is fixed. 
     Accordingly, the invention allows electrical energy to be utilized very efficiently by utilizing the longitudinal vibration caused by the piezoelectric longitudinal effect whose electrical-mechanical coupling coefficient is large, vibration loss to be suppressed, the vibrating direction to be prevented from varying, the structure of the device to be miniaturized and the production process to be simplified. 
     The invention is further characterized in that the first and second piezoelectric bodies have second polarized portions further at positions corresponding to the first polarized portions. 
     Thereby, elliptic vibration for rotating in the reverse direction may be taken out by exciting only the second polarized portions of the respective piezoelectric bodies to produce bending vibration having a different phase, for example. Alternatively, the bending vibration may be amplified by exciting the second polarized portion with a different phase from the first polarized portion in the same time. Accordingly, driving force in the both normal and reverse directions may be obtained and the output may be controlled by displacing the bending vibration or by changing the phase. 
     The invention is further characterized in that a third piezoelectric body which vibrates in the same phase with the stretching vibration is laminated in a body of the ultrasonic motor. 
     Thereby, the third piezoelectric body vibrates in the longitudinal direction in the same phase with the stretching vibration and amplifies the stretching vibration. Accordingly, the high-output ultrasonic motor may be realized. 
     The invention is further characterized in that a third polarized portion that vibrates in the same phase with the stretching vibration is provided between the first polarized portion of the first piezoelectric body and the first polarized portion of the second piezoelectric body at least in either one of the first piezoelectric body and the second piezoelectric body. Thereby, the third polarized portion vibrates in the longitudinal direction in the same phase with the stretching vibration and amplifies the stretching vibration. Accordingly, the high-output ultrasonic motor may be realized. 
     Here, the third polarized portion may be provided only in the first piezoelectric body, only in the second piezoelectric body or in the first and second piezoelectric bodies. 
     The invention described is further characterized in that the moving body of the ultrasonic motor is abutted to the laminated piezoelectric vibrator in the horizontal direction. 
     Thereby, the laminated piezoelectric vibrator moves the moving body by the vibration combined in the horizontal direction. 
     The invention is further characterized in that the laminated piezoelectric vibrator is abutted at least at one point of a spherical moving body of the ultrasonic motor described in any one of the foregoing embodiments. 
     Thereby, the spherical moving body may be moved about an arbitrary axis by applying a driving force to one point of the spherical moving body by the laminated piezoelectric vibrator or may be moved arbitrary by applying a driving force to a plurality of points. 
     The invention is further characterized in that an electronic apparatus equipped with the ultrasonic motor comprises the ultrasonic motor described in any one of the foregoing embodiments. Thereby, the electronic apparatus equipped with the ultrasonic motor having the ultrasonic motor as a driving source may be realized. 
     The specific nature of the invention, as well as other objects, uses and advantages thereof, will clearly appear from the following description and from the accompanying drawings in which like numerals refer to like parts. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1 a  and  1   b  are explanatory drawings showing a first embodiment in which the present invention is applied to an ultrasonic motor, wherein FIG. 1 a  shows a sectional structure thereof and FIG. 1 b  shows a planar structure thereof; 
     FIGS. 2 a  through  2   d  are explanatory diagrams, wherein FIGS. 2 a  and  2   c  show the planar structure of the piezoelectric vibrator shown in FIG.  1  and FIGS. 2 b  and  2   d  show the structure of the piezoelectric body; 
     FIGS. 3 a  and  3   b  are explanatory diagrams, wherein FIG. 3 a  shows a structure of one side electrode shown in FIG.  1  and FIG. 3 b  shows a structure of another side electrode shown in FIG. 1; 
     FIG. 4 is an explanatory diagram showing a vibrating state of the vibrator shown in FIG. 1; 
     FIGS. 5 a  through  5   f  show a second embodiment in which the present invention is applied to an ultrasonic motor, wherein FIGS. 5 a,    5   c  and  5   e  show a planar structure of the piezoelectric vibrator and FIGS. 5 b,    5   d  and  5   f  show a planar structure of the piezoelectric body; 
     FIGS. 6 a  and  6   b  are explanatory diagrams, wherein FIG. 6 a  shows disposition of one side electrode shown in FIG.  5  and FIG. 6 b  shows disposition of another side electrode; 
     FIGS. 7 a  through  7   d  are explanatory drawings showing a third embodiment in which the present invention is applied to an ultrasonic motor, wherein FIGS. 7 a  and  7   c  shows a planar structure of the piezoelectric vibrator and FIGS. 7 b  and  7   d  show a planar structure of the piezoelectric body; 
     FIGS. 8 a  and  8   b  are explanatory diagrams, wherein FIG. 8 a  shows disposition of one side electrode shown in FIG.  7  and FIG. 8 b  shows disposition of another side electrode; 
     FIGS. 9 a  through  9   d  are explanatory drawings showing a fourth embodiment in which the present invention is applied to an ultrasonic motor, wherein FIGS. 9 a  and  9   c  shows a planar structure of the piezoelectric vibrator and FIGS. 9 b  and  9   d  show a planar structure of the piezoelectric body; 
     FIGS. 10 a  and  10   b  are explanatory diagrams, wherein FIG. 10 a  shows disposition of one side electrode shown in FIG.  9  and FIG. 10 b  shows disposition of another side electrode; 
     FIGS. 11 a  through  11   f  are explanatory drawings showing a fifth embodiment in which the present invention is applied to an ultrasonic motor, wherein FIGS. 11 a,    11   c,  and  11   e  shows a planar structure of the piezoelectric vibrator and FIGS. 11 b,    11   d,  and  11   f  show a planar structure of the piezoelectric body; 
     FIGS. 12 a  and  12   b  are explanatory diagrams, wherein FIG. 12 a  shows disposition of one side electrode shown in FIG.  11  and FIG. 12 b  shows disposition of another side electrode; 
     FIG. 13 is an explanatory diagram showing a side structure of a sixth embodiment in which the present invention is applied to an ultrasonic motor; 
     FIG. 14 is an explanatory diagram showing a structure of a seventh embodiment in which the present invention is applied to an ultrasonic motor; 
     FIG. 15 is an explanatory diagram showing a block of an eight embodiment in which the present invention is applied to an ultrasonic motor; and 
     FIG. 16 is a perspective view showing a structure of a prior art ultrasonic motor. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Preferred embodiments to which the present invention has been applied will be explained below in detail with reference to FIGS. 1 through 15. 
     [First Embodiment] 
     FIGS. 1 a  and  1   b  are explanatory drawings showing a first embodiment in which the present invention is applied to an ultrasonic motor, wherein FIG. 1 a  shows a sectional structure thereof and FIG. 1 b  shows a planar structure thereof. 
     As shown in FIGS. 1 a  and  1   b,  according to the present embodiment, the ultrasonic motor comprises a vibrating body  10 , an output fetching member  31  provided on an end of the vibrating body  10  in the laminating direction, a moving body  50  abutting with the output fetching member  31  and pressurizing mechanisms  41  and  42  for supporting the vibrating body  10  and pressurizing the moving body  50  and the output fetching member  31 . 
     The moving body  50  comprises a rotor  51  having a rotary bearing, a rotary shaft  52  penetrating through the rotor  51  and a fixing member  53  for fixing the basal end of the rotary shaft  52 . 
     The output fetching member  31  is a rectangular parallelepiped member having a rigidity. It is provided to transmit vibration of the vibrating body  10  to the rotor  51  and to amplify displacement of the vibration. 
     The pressurizing mechanisms  41  and  42  comprise a fixing member  42  provided so as to face to the vibrating body  10  and a pressurizing member  41  for pressurizing the vibrating body  10  toward the moving body  50 . 
     The vibrating body  10  is constructed by alternately laminating piezoelectric bodies  11 A,  11 B,  11 C,  11 D and  11 E and piezoelectric bodies  12 A,  12 B,  12 C,  12 D and  12 E in a body such that the piezoelectric body  11 A and piezoelectric body  12 A are paired and the piezoelectric body  11 B and  12 B are paired, for example. 
     Planar electrodes  21  are fixed on one end face of the respective piezoelectric bodies  11 A through  11 E at a region corresponding to polarization and reference electrodes  22  are fixed on the face of the respective piezoelectric bodies  12 A through  12 E facing the planar electrodes  21  of the piezoelectric bodies  11 A through  11 E as counter electrodes. 
     FIGS. 2 a  through  2   d  show the planar structure of the piezoelectric bodies  11 A through  11 E and the piezoelectric bodies  12 A through  12 E and patterns of the electrodes  21  and  22 . 
     It is noted that the piezoelectric body  11 A as a first piezoelectric body of the invention is identical with the piezoelectric bodies  11 B and  11 C and the piezoelectric body  11 D as a second piezoelectric body of the invention is identical with the piezoelectric body  11 E. The piezoelectric body  12 A is also identical with the piezoelectric bodies  12 B through  12 E, so that only the piezoelectric bodies  11 A and  11 D and the piezoelectric bodies  12 A and  12 D which are paired with them will be explained below as the representative piezoelectric bodies. 
     As shown in FIGS. 2 a  through  2   d,  the piezoelectric bodies  11 A and  11 D and the piezoelectric bodies  12 A and  12 D are rectangular plate-like members for which a ferroelectric material such as barium titanate and lead zirconate titanate is used. The aspect ratio of the vibrating body  10  is set so as to cause a predetermined resonance frequency. 
     As shown in FIGS. 2 a  and  2   c,  long sides of the rectangular plane of the piezoelectric bodies  11 A and  11 D are bisected so as to divide the plane into two parts  11   a  and  11   b  and  11   c  and  11   d  and planar electrodes  21   a  and  21   b  and  21   c  and  21   d  are fixed in correspondence to the respective polarized portions  11   a  through  11   d.    
     Part of the one planar electrode  21   a  fixed to the piezoelectric body  11 A is connected with a side electrode described later at one long edge of the rectangular plane of the piezoelectric body  11 A and part of the other planar electrode  21   b  is connected with the side electrode at the other long edge of the rectangular plane. Further, part of the planar electrode  21   d  fixed to the piezoelectric body  11 D is connected with the side electrode at one long edge of the rectangular plane and part of the planar electrode  21   c  is connected thereto at the other long edge of the rectangular plane. 
     Reference electrodes  22   a  and  22   b  are fixed almost on the whole surface of the rectangular plane of the piezoelectric bodies  12 A and  12 D as the reference for the planar electrodes  21   a  and  21   b  and  21   c  and  21   d  as shown in FIG. 2 b.  Part of the reference electrodes  22   a  and  22   b  is connected with the side electrode at the other long edge of the rectangular plane. 
     A polarization process is implemented on the vibrating body  10  laminated in a body by applying a voltage exceeding a resistive electric field based on the electrodes  22  and by setting the electrodes  21  as plus as shown in the figures. 
     FIGS. 3 a  and  3   b  show patterns of the side electrodes  32 ,  33 ,  34 ,  35  and  36  provided along the plane of lamination of the vibrating body  10 . 
     The side electrodes  32  through  34  are provided on one side face corresponding to the long edge of the vibrating body  10  as shown in FIG. 3 a  and the side electrodes  35  and  36  are provided on the other side face as shown in FIG. 3 b.    
     Here, the side electrode  32  is connected to the planar electrodes  21   b  of the piezoelectric bodies  11 A through  11 C, the side electrode  33  is connected to the reference electrodes  22   a  and  22   b  of the piezoelectric bodies  12 A through  12 E and the side electrode  34  is connected to the planar electrodes  21   c  of the piezoelectric bodies  11 D and  11 E. Meanwhile, the side electrode  35  is connected to the planar electrodes  21   a  of the piezoelectric bodies  11 A through  11 C and the side electrode  36  is connected to the planar electrodes  21   d  of the piezoelectric bodies  11 D and  11 E. 
     Next, a first use of the ultrasonic motor will be explained based on FIGS. 2 through 4. 
     When voltage is applied to the respective side electrodes  32 ,  33  and  34  shown in FIG. 3 a  to normally rotate the rotor  51  at first, voltage having the same phase is applied to the planar electrodes  21   b  of the piezoelectric bodies  11 A through  11 C, the reference electrodes  22   a  and  22   b  of the piezoelectric bodies  12 A through  12 E and the planar electrodes  21   c  of the piezoelectric bodies  11 D and  11 E as shown in FIG.  2 . 
     The polarized portions  11   b  of the piezoelectric bodies  11 A through  11 C and the polarized portions  11   c  of the piezoelectric bodies  11 D and  11 E as first polarized portions to which the voltage is applied stretch respectively in the direction parallel to the direction in which the voltage is applied (hereinafter referred to as a piezoelectric longitudinal effect). 
     FIG. 4 shows a vibrating state of the vibrating body  10 . 
     When the polarized portions  11   b  of the piezoelectric bodies  11 A through  11 C and the polarized portions  11   c  of the piezoelectric bodies  11 D and  11 E stretch in the longitudinal direction due to the piezoelectric longitudinal effect, the vibrating body  10  causes bending vibration A as well as stretching vibration B as a whole as shown in the figure. 
     Here, an electric-mechanical coupling coefficient of the piezoelectric longitudinal effect is greater than that of the piezoelectric transverse effect, and an overall energy efficiency is enhanced by utilizing the piezoelectric longitudinal effect. 
     Further, the vibration of each vibrator is not suppressed and the vibrating direction is also fixed by laminating the piezoelectric vibrators  11 A through  11 E in a body without using any fixing means. 
     Then, the output fetching member  31  transmits and amplifies elliptic vibration C obtained by combining the bending vibration A and the stretching vibration B. 
     The rotor  51  abutting with the output fetching member  31  rotates in the normal direction by periodically receiving frictional force of the fixed direction. 
     Meanwhile, the rotor  51  may be rotated in the opposite direction as follows. When voltage is applied to the respective side electrodes  33 ,  35  and  36  shown in FIG. 3, voltage having the same phase is applied to the planar electrodes  21   a  of the piezoelectric bodies  11 A through  11 A, the reference electrodes  22   a  and  22   b  of the piezoelectric bodies  12 A through  12 E and the planar electrodes  21   d  of the piezoelectric bodies  11 D and  11 E as shown in FIG.  2 . 
     At this time, the polarized portions  11   a  and the polarized portions  11   d  as second polarized portions of the present invention are excited and the vibrating body  10  causes the stretching vibration B and bending vibration whose phase differs by 180° from the above-mentioned bending vibration A. 
     Then, elliptic vibration in the opposite direction from the elliptic vibration C is produced at the edge of the output fetching member  31  and the rotor  51  receives frictional force in the opposite direction, thus rotating in the opposite direction. 
     A second use of the ultrasonic motor will be explained further. 
     That is, voltage having the same phase is applied to the side electrodes  32  and  34  shown in FIG.  3  and voltage having the same phase and different from that applied to the side electrodes  32  and  34  is applied to the side electrodes  35  and  36 . 
     At this time, when the polarized portions  21   b  of the piezoelectric bodies  11 A through  11 C and the polarized portions  11   c  of the piezoelectric bodies  11 D and  11 E contract in the longitudinal direction, for example, it corresponds to stretching of the polarized portions  11   a  of the piezoelectric bodies  11 A through  11 C and the polarized portions  11   d  of the piezoelectric bodies  11 D and  11 E in the longitudinal direction. 
     Thereafter, the bending vibration and the stretching vibration are combined and the output fetching member  31  causes modified elliptic vibration. 
     It is noted that the phase difference of the voltages applied to the side electrodes  32  and  34  and the side electrodes  35  and  36  may be appropriately changed. 
     Thereby, according to the present embodiment, the polarized portions  21   a  through  21   d  of the respective piezoelectric bodies  11 A through  11 E are excited respectively in the longitudinal direction and the stretching vibration is produced by overlapping the respective vibrations in the longitudinal direction, so that electrical energy may be utilized very efficiently by utilizing the large exciting force. 
     Further, because the vibration is not suppressed and the vibrating direction is fixed by laminating the piezoelectric bodies  11 A through  11 E in a body without using any fixing means, vibration loss of the respective piezoelectric bodies  11 A through  11 E may be suppressed, the vibrating direction may be prevented from varying and the structure of the device may be simplified. 
     Further, the driving force in the both normal and reverse directions may be obtained just by changing the phase of the voltage for exciting the polarized portions  11   b  and  11   c  and the polarized portions  11   a  and  11   d.    
     [Second Embodiment] 
     FIGS. 5 and 6 show a second embodiment in which the present invention is applied to an ultrasonic motor, wherein FIGS.  5   a  through  5   f  show a basic laminating structure of the vibrating body  10  and FIGS. 6 a  and  6   b  show disposition of side electrodes. 
     As shown in FIGS. 5 a,    5   b,    5   e  and  5   f,  the piezoelectric bodies  11 A and  11 B and the piezoelectric bodies  12 A and  12 C which are paired with one another are constructed almost in the same manner as in the first embodiment, so that their explanation will be omitted here. 
     The present embodiment is characterized in that a piezoelectric body  13 A, i.e., a third piezoelectric body, in which a planar electrode  23   a  is fixed almost on the whole surface of the rectangular plane thereof and a piezoelectric body  12 B that is paired with the piezoelectric body  13 A are inserted between the pair of piezoelectric bodies  11 A and  11 B as shown in FIGS. 5 c  and  5   d.  A polarization process is implemented on the piezoelectric body  13 A in correspondence to the planar electrode  23   a  and a reference electrode  22   b  is fixed to the piezoelectric body  12 B as a counter electrode. 
     As shown in FIG. 6 a,  the side electrode  32  is connected to the planar electrode  21   b  on the front right side of the piezoelectric body  11 A, the side electrode  33  is connected to the reference electrodes  22   a,    22   b  and  22   c  of the piezoelectric bodies  12 A,  12 B and  12 C and the side electrode  34  is connected to the planar electrode  21   c  on the front left side of the piezoelectric body  11 B. 
     Further, as shown in FIG. 6 b,  the side electrode  35  is connected to the planar electrode  11   a  on the front left side of the piezoelectric body  11 A, the side electrode  36  is connected to the planar electrode  21   d  on the front right side of the piezoelectric body  11 B and the side electrode  37  is connected to the planar electrode  23   a  of the piezoelectric body  13 A. 
     Next, a first use of the present embodiment will be explained based on FIGS. 5 and 6. 
     When voltage is applied to the side electrodes  32 ,  33 ,  34  and  37  shown in FIG. 6 to normally rotate the rotor  51  at first, voltage having the same phase is applied to the planar electrodes  21   b  on the front right side of the piezoelectric body  11 A, the reference electrodes  22   a,    22   b  and  22   c  of the piezoelectric bodies  12 A through  12 C, the planar electrode  21   c  on the front left side of the piezoelectric body  11 B and the planar electrode  23   a  of the piezoelectric body  13 A as shown in FIG.  5 . 
     At this time, the vibrating body  10  causes stretching vibration and bending vibration when the polarized portion  11   b  on the front right side of the piezoelectric body  11 A and the polarized portion  11   c  on the front left side of the piezoelectric body  11 B, i.e., the first polarized portions, are excited. 
     The piezoelectric body  13 A also causes stretching vibration in the same phase, thus amplifying the stretching vibration of the vibrating body  10 . 
     Then, the output fetching member  31  causes elliptic vibration and the rotor  51  rotates normally by receiving the frictional force. 
     The rotor  51  may be rotated in the opposite direction as follows. When voltage is applied to the side electrodes  33 ,  35 ,  36  and  37  shown in FIG. 6, voltage having the same phase is applied to the planar electrode  21   a  on the front left side of the piezoelectric body  11 A, the reference electrodes  22   a  through  22   c  of the piezoelectric bodies  12 A through  12 C, the planar electrode  21   d  on the front right side of the piezoelectric body  11 B and the planar electrode  23   a  of the piezoelectric body  13 A, respectively, as shown in FIG.  5 . 
     The polarized portion  11   a  on the front left side of the piezoelectric body  11 A, the polarized portion  21   d  on the front right side of the piezoelectric body  11 B and almost the whole plane of the piezoelectric body  13 A, i.e., the second polarized portions, are excited and the vibrating body  10  causes stretching vibration and bending vibration. Then, the output fetching member  31  causes elliptic vibration in the opposite direction and rotates the rotor  51  in the opposite direction. 
     Meanwhile, in a second use of the ultrasonic motor of the present embodiment, at least two groups among three groups of the side electrodes  32  and  34 , the side electrodes  35  and  36  and the side electrode  37  are selected and voltages having different phases are applied to the respective groups. 
     When the two groups of the side electrodes  32  and  34  and the side electrode  37  are selected for example, the output fetching member  31  causes elliptic vibration having a mode different from the elliptic vibration in the first use. 
     It is also possible to apply different voltages to the respective groups to vary the elliptic vibration drawn by the output fetching member  31 . 
     As described above, according to the present embodiment, the high-output ultrasonic motor may be realized because the stretching vibration is amplified by the piezoelectric body  13 A. 
     [Third Embodiment] 
     FIGS. 7 and 8 show a third embodiment in which the present invention is applied to an ultrasonic motor, wherein FIGS. 7 a  through  7   d  show a basic laminating structure and FIGS. 8 a  and  8   b  show disposition of side electrodes. 
     As shown in FIGS. 7 b  and  7   d,  the piezoelectric bodies  12 A and  12 B which are paired with piezoelectric bodies  14 A and  14 B are constructed almost in the same manner as in the first embodiment, so that their explanation will be omitted here. 
     The present embodiment is characterized in that rectangular planes of the piezoelectric bodies  14 A and  14 B as first and second piezoelectric vibrators are divided into three parts and planar electrodes  24   a  through  24   c  and  24   d  through  24   f  are fixed corresponding to the respective divided planes  14   a  through  14   c  and  14   d  through  14   f  as shown in FIGS. 7 a  and  7   c.  Then, a polarization process is implemented on the respective divided planes  14   a  through  14   c  and  14   d  through  14   f  by setting the front page side thereof as plus and the back side thereof as minus and by applying a voltage exceeding a resistive electric field to the planar electrodes  21   a  through  21   d.    
     Part of one planar electrode  24   a  fixed to the piezoelectric vibrator  14 A is connected at one long edge of the rectangular plane of the piezoelectric body  14 A and part of the planar electrodes  24   b  and  24   c  is connected at the other long edge of the rectangular plane. Further, part of the planar electrode  24   e  fixed to the piezoelectric body  14 B is connected at one long edge of the rectangular plane and part of the planar electrodes  24   d  and  24   f  is connected at the other long edge of the rectangular plane. 
     The side electrode  32  shown in FIG. 8 a  is connected to the planar electrode  24   b  on the front right side of the piezoelectric body  14 A, the side electrode  34  is connected to the planar electrode  24   d  on the front left side of the piezoelectric body  14 B and the side electrode  37  is connected to the planar electrodes  24   c  and  24   f  at the front center of the planar electrodes  14 A and  14 B. 
     Further, the side electrode  35  shown in FIG. 8 b  is connected to the planar electrode  24   a  on the front left side of the piezoelectric body  14 A, the side electrode  36  is connected to the planar electrode  24   e  on the front right side of the piezoelectric body  14 B and the side electrode  33  is connected to the reference electrodes  22   a  and  22   b  of the piezoelectric bodies  12 A and  12 B. 
     Next, a first use of the present embodiment will be explained based on FIGS. 7 and 8. 
     When voltage is applied to the side electrodes  32 ,  34  and  37  based on the side electrode  33  as shown in FIG. 8 to normally rotate the rotor  51  at first, voltage having the same phase is applied to the planar electrode  24   b  on the front right side of the piezoelectric body  14 A, the planar electrode  24   c  at the center thereof, the planar electrode  24   d  on the front left side of the piezoelectric body  14 B, the planar electrode  24   f  at the center thereof and the reference electrodes  22   a  and  22   b  of the piezoelectric bodies  12 A and  12 B as shown in FIG.  7 . 
     At this time, the vibrating body  10  causes stretching vibration and bending vibration when the polarized portion  14   b  on the front right side of the piezoelectric body  14 A and the polarized portion  14   d  on the front left side of the piezoelectric body  14 B as the first polarized portions are excited. 
     The polarized portion  14   c  at the center of the piezoelectric body  14 A and the polarized portion  14   f  at the center of the piezoelectric body  14 B as third polarized portions causes stretching vibration in the longitudinal direction, thus amplifying the stretching vibration of the vibrating body  10 . 
     Then, the output fetching member  31  causes elliptic vibration and the rotor  51  rotates normally by receiving the frictional force. 
     The rotor  51  may be rotated in the opposite direction as follows. That is, when a voltage is applied to the side electrodes  35 ,  36  and  37  based on the side electrode  33  shown in FIG. 8, voltage having the same phase is applied to the planar electrode  24   a  on the front left side of the piezoelectric body  14 A, the planar electrode  24   c  at the center thereof, the planar electrode  24   e  on the front right side of the piezoelectric body  14 B, the planar electrode  24   f  at the center thereof and the reference electrodes  22   a  and  22   b  of the piezoelectric bodies  12 A and  12 B as shown in FIG.  7 . 
     The polarized portion  14   a  on the front left side of the piezoelectric body  14 A as the second polarized portion, the polarized portion  14   c  at the center as the third polarized portion, the polarized portion  24   e  on the front right side of the piezoelectric body  14 B and the polarized portion  24   f  at the center as the third polarized portion are excited and the vibrating body  10  causes stretching vibration and bending vibration. Then, the output fetching member  31  causes elliptic vibration in the opposite direction and rotates the rotor  51  in the opposite direction. 
     Meanwhile, as a second use of the ultrasonic motor of the present embodiment, at least two groups among three groups of the side electrodes  32  and  34 , the side electrodes  35  and  36  and the side electrode  37  are selected and voltages having different phases are applied to the respective groups. 
     When the two groups of the side electrodes  32  and  34  and the side electrode  37  are selected for example, the output fetching member  31  causes different elliptic vibration from the elliptic vibration in the first use. 
     It is also possible to apply different voltages to the respective groups to variegate the elliptic vibration drawn by the output fetching member  31 . 
     As described above, according to the present embodiment, the high-output ultrasonic motor may be obtained because the polarized portion  14   c  at the center of the piezoelectric body  14 A and the polarized portion  14   f  at the center of the piezoelectric body  14 B are provided to amplify the stretching vibration in the longitudinal direction. 
     [Fourth Embodiment] 
     FIGS. 9 and 10 show a fourth embodiment in which the present invention is applied to an ultrasonic motor, wherein FIGS. 9 a  through  9   d  show a basic laminating structure and FIGS. 10 a  and  10   b  show disposition of side electrodes. 
     As shown in FIGS. 9 b  and  9   d,  the piezoelectric bodies  12 A and  12 B which are paired with piezoelectric bodies  15 A and  15 B are constructed almost in the same manner with the first embodiment, so that their explanation will be omitted here. 
     The present embodiment is characterized in that rectangular planes of the piezoelectric bodies  15 A and  15 B are divided into three parts and planar electrodes  25   a,    25   b,    25   c,    25   d,    25   e  and  25   f  are fixed corresponding to the respective divided planes  15   a  through  15   c  and  15   d  through  15   f  as shown in FIGS. 9 a  and  9   c.  Then, a polarization process is implemented on the planar electrodes  25   b  and  25   c  of the piezoelectric body  15 A and the planar electrodes  25   d  and  25   f  of the piezoelectric body  15 B by setting the front page side thereof as plus and the back side thereof as minus and on the planar electrode  25   a  of the piezoelectric body  15 A and the planar electrode  25   e  of the piezoelectric body  15 B by setting the front page side thereof as minus and the back side thereof as plus. 
     Part of one planar electrode  25   a  fixed to the planar electrode  15 A is connected at one long edge of the rectangular plane of the piezoelectric body  15 A and part of the planar electrodes  25   b  and  25   c  is connected at the other long edge of the rectangular plane. Further, part of the planar electrode  25   e  fixed to the piezoelectric body  15 B is connected at one long edge of the rectangular plane and part of the planar electrodes  25   d  and  25   f  is connected at the other long edge of the rectangular plane. 
     The side electrode  32  shown in FIG. 10 a  is connected to the planar electrode  25   b  on the front right side of the planar electrode  15 A, the side electrode  34  is connected to the planar electrode  25   d  on the front left side of the piezoelectric body  15 B and the side electrode  37  is connected to the planar electrodes  25   c  and  25   f  at the front center of the piezoelectric bodies  15 A and  15 B. 
     Further, the side electrode  35  shown in FIG. 10 b  is connected to the planar electrode  25   a  on the front left side of the piezoelectric body  15 A, the side electrode  36  is connected to the planar electrode  25   e  on the front right side of the piezoelectric body  15 B and the side electrode  33  is connected to the reference electrodes  22   a  and  22   b  of the piezoelectric bodies  12 A and  12 B. 
     Next, a first use of the present embodiment will be explained based on FIGS. 9 and 10. 
     When voltage is applied to all of the side electrodes  32 ,  34 ,  35 ,  36  and  37  based on the side electrode  33  shown in FIG. 10 to normally rotate the rotor  51  at first, voltage having the same phase is applied to the planar electrodes  25   a  through  25   c  of the piezoelectric body  15 A, the planar electrodes  25   d  through  25   f  of the piezoelectric body  15 B and the reference electrodes  22   a  and  22   b  of the piezoelectric bodies  12 A and  12 B as shown in FIG.  9 . 
     At this time, when the polarized portion  15   b  on the front right side of the piezoelectric body  15 A and the polarized portion  15   d  on the front left side of the piezoelectric body  15 B as the first polarized portions are stretched in the longitudinal direction, the polarized portion  15   a  on the front left side of the piezoelectric body  15 A and the polarized portion  15   d  on the front right side of the piezoelectric body  15 B as second polarized portions contract in the longitudinal direction, thus amplifying the bending vibration of the vibrating body  10 . 
     The polarized portion  15   c  at the center of the piezoelectric body  15 A and the polarized portion  15   f  at the center of the piezoelectric body  15 B as third polarized portions causes stretching vibration in the same phase in the longitudinal direction, thus amplifying the stretching vibration of the vibrating body  10 . 
     Then, the output fetching member  31  causes amplified elliptic vibration and the rotor  51  rotates normally at high speed by receiving the greater frictional force. 
     As described above, according to the present embodiment, the rotor  51  rotates at higher speed and the high-output ultrasonic motor may be obtained because the polarization process of the piezoelectric bodies  15 A and  15 B is arranged so as to amplify both of the stretching vibration and bending vibration of the vibrating body  10  and so that the output fetching member  31  causes amplified elliptic vibration. 
     [Fifth Embodiment] 
     FIGS. 11 and 12 show a fifth embodiment in which the present invention is applied to an ultrasonic motor, wherein FIGS. 11 a  through  11   f  show a basic laminating structure and FIGS. 12 a  and  12   b  show disposition of side electrodes. 
     As shown in FIGS. 11 b,    11   c,    11   d  and  11   f,  the present embodiment are constructed almost in the same manner as in the second embodiment, so that the explanation on the piezoelectric body  13 A, piezoelectric bodies  12 A,  12 B and  12 C will be omitted here. 
     The present embodiment is characterized in that a long side of rectangular planes of the piezoelectric bodies  16 A and  16 B as the first and second piezoelectric bodies are bisected and planar electrodes  26   a,    26   b,    26   c  and  26   d  are fixed corresponding to the respective bisected planes  16   a,    16   b,    16   c  and  16   d  as shown in FIGS. 11 a  and  11   c.  Then, a polarization process is implemented on the planar electrode  26   b  of the piezoelectric body  16 A and the planar electrode  26   c  of the piezoelectric body  16 B by setting the front page side thereof as plus and the back side thereof as minus and on the planar electrode  26   a  of the piezoelectric body  16 A and the planar electrode  26   d  of the piezoelectric body  16 B by setting the front page side thereof as minus and the back side thereof as plus. 
     Part of one planar electrode  26   a  fixed to the piezoelectric body  16 A is connected with the side electrode described later at one long edge of the rectangular plane of the piezoelectric body  16 A and part of the other planar electrode  26   b  is connected with the side electrode at the other long edge of the rectangular plane. Further, part of the planar electrode  26   d  fixed to the piezoelectric body  16 B is connected at one long edge of the rectangular plane and part of the planar electrode  26   c  is connected at the other long edge of the rectangular plane. 
     As shown in FIG. 12 a,  the side electrode  32  is connected to the planar electrode  26   b  on the front right side of the planar electrode  16 A, the side electrode  33  is connected to the reference electrodes  22   a,    22   b  and  22   c  of the piezoelectric bodies  12 A,  12 B and  12 C, the side electrode  34  is connected to the planar electrode  26   c  on the front left side of the piezoelectric body  16 B. 
     Further, as shown in FIG. 6 b,  the side electrode  35  is connected to the planar electrode  26   a  on the front left side of the piezoelectric body  16 A, the side electrode  36  is connected to the planar electrode  26   d  on the front right side of the piezoelectric body  16 B and the side electrode  37  is connected to the planar electrode  23   a  of the piezoelectric body  13 A. 
     Next, the use of the present embodiment will be explained based on FIGS. 11 and 12. 
     When voltage is applied to all of the side electrodes  32 ,  33 ,  34 ,  35 ,  36  and  37  as shown in FIG. 12 to normally rotate the rotor  51  at first, voltage having the same phase is applied to the planar electrodes  26   a  and  26   b  of the piezoelectric body  16 A, the planar electrodes  26   c  and  26   d  of the piezoelectric body  16 B, the planar electrode  23   a  of the piezoelectric body  13 A and the reference electrodes  22   a,    22   b  and  22   c  of the piezoelectric bodies  12 A,  12 B and  12 C as shown in FIG.  11 . 
     At this time, when the polarized portion  16   b  on the front right side of the piezoelectric body  16 A and the polarized portion  16   c  on the front left side of the piezoelectric body  16 B as the first polarized portions are stretched in the longitudinal direction, the polarized portion  16   a  on the front left side of the piezoelectric body  16 A and the polarized portion  16   d  on the front right side of the piezoelectric body  16 B as second polarized portions contract in the longitudinal direction, thus amplifying the bending vibration of the vibrating body  10 . 
     The piezoelectric body  13 A as the third piezoelectric body causes stretching vibration in the same phase in the longitudinal direction, thus amplifying the stretching vibration of the vibrating body  10 . 
     Then, the output fetching member  31  causes amplified elliptic vibration and the rotor  51  rotates normally at higher speed by receiving the greater frictional force. 
     As described above, according to the present embodiment, the rotor  51  rotates at higher speed and a high output may be obtained because the present embodiment is arranged so that the bending vibration is amplified by the polarized portion  16   a  on the front left side of the piezoelectric body  16 A and the polarized portion  16   d  on the front right side of the piezoelectric body  16 B and the stretching vibration of the vibrating body  10  is amplified by the piezoelectric body  13 A and the stretching vibration and the bending vibration of the vibrating body  10  are both amplified. 
     [Sixth Embodiment] 
     FIG. 13 shows a side structure of a sixth embodiment in which the present invention is applied to an ultrasonic motor. 
     While the present embodiment is constructed almost in the same manner as in the first embodiment, it is characterized in that the vibrating body  10  is fixed, a pair of output fetching members  38  and  39  are fixed at the edge portion thereof in the direction vertical to the laminating direction and the output fetching members  38  and  39  are abutted with a moving body  54 . 
     Thereby, elliptic vibration obtained by combining bending vibration and stretching vibration is produced even in the horizontal direction of the vibrating body  10 , so that the moving body  54  abutting with the output fetching members  38  and  39  can move linearly in the right or left direction by using the piezoelectric vibrators as described above. 
     [Seventh Embodiment] 
     FIG. 14 shows a structure of a seventh embodiment in which the present invention is applied to an ultrasonic motor. 
     The present embodiment is characterized in that two vibrating bodies  10 A and  10 B are disposed while opening by 90° with respect to a spherical rotor  55  centering on a point Z in the figure and respective output fetching members  31 A and  31 B abut with the spherical rotor  55 . 
     Here, the vibrating bodies  10 A and  10 B have the same laminating structure and disposition of electrodes as in the second embodiment and only the stretching vibration, only the bending vibration or the combined elliptic vibration may be produced by selecting the electrodes to which voltage is applied. 
     The use of the present embodiment will be explained below based on FIG.  14 . 
     The spherical rotor  55  may be moved in triaxial directions by vibrating both vibrating bodies  10 A and  10 B. At this time, the output fetching members  31 A and  31 B cause elliptic vibration, respectively. The output fetching member  31 A applies frictional force in the direction of rotation about the Z-axis of the spherical rotor  55  and the output fetching member  31 B applies frictional force in the direction of rotation about the X-axis of the spherical rotor  55 . The spherical rotor  55  rotates about the X and Z-axes in the same time, thus realizing the triaxial movement. 
     Meanwhile, the spherical rotor  55  may be rotated in one direction by causing the vibrating body  10 A to produce combined vibration and the vibrating body  10 B to produce only stretching vibration. 
     At this time, the output fetching member  31 A applies frictional force to the spherical rotor  55  in the direction of rotation about the Z-axis and the output fetching member  31 B stretches and applies force only in the direction of the center of the spherical rotor  55 , so that they do not hamper the spherical rotor  55  from rotating about the Z-axis. 
     As described above, according to the present embodiment, the use of the two vibrating bodies  10 A and  10 B allows the rotational movement in one direction and the triaxial movement of the spherical rotor  55  to be realized. 
     [Eighth Embodiment] 
     FIG. 15 is a block diagram showing an eighth embodiment in which the inventive ultrasonic motor is applied to an electronic apparatus. 
     The electronic apparatus comprises the above-mentioned vibrating body  10 , a moving body  61  moved by the vibrating body  10 , a pressurizing mechanism  62  for applying pressurizing force to the moving body  61  and the vibrating body  10 , a transmission mechanism  63  operating in linkage with the moving body  61  and an output mechanism  64  that moves based on the operation of the transmission mechanism  63 . 
     Here, a transmission wheel such as a gear and a frictional gear is used as the transmission mechanism  63 . As the output mechanism  64 , a shutter driving mechanism and a lens driving mechanism are used in the case of a camera for example, a needle driving mechanism and a calendar driving mechanism are used in case of an electronic watch, and a cutter feeding mechanism and a workpiece feeding mechanism are used in case of a work machine. 
     The electronic apparatus equipped with the ultrasonic motor of the present embodiment may be realized in electronic watches, measuring instruments, cameras, printers, work machines, robots, moving apparatuses and the like. 
     Further, a driving mechanism may be realized just by the ultrasonic motor itself by attaching an output shaft to the moving body  61  and by comprising a power transmission mechanism for transmitting torque from the output shaft. 
     As described above, according to the invention, as the inventive ultrasonic motor is arranged such that the polarized portion of the first piezoelectric body and the polarized portion of the second piezoelectric body stretch respectively in the polarizing direction so that stretching vibration and bending vibration are produced by overlapping the respective vibrations in the longitudinal direction. The output may be increased by utilizing the vibration in the longitudinal direction caused by the piezoelectric longitudinal effect and electrical energy may be utilized very efficiently. 
     Further, the piezoelectric vibrators are laminated in a body without using fixing means so as not to suppress the vibration and to fix the vibrating direction, vibration loss of the respective piezoelectric vibrators may be suppressed, the vibrating direction may be prevented from varying and the structure of the device may be simplified. 
     According to the invention, a driving force in both normal and reverse directions may be obtained and the output may be controlled by displacing the bending vibration or by changing the phase because the elliptic vibration for rotating in the reverse direction is taken out by causing bending vibration having a different phase or by amplifying the bending vibration by exciting the second polarized portion with a phase different from the first polarized portion in the same time. 
     According to the invention, by providing a third piezoelectric body which vibrates in the same phase with the stretching vibration, the high-output ultrasonic motor may be realized because the stretching vibration is amplified. 
     According to the invention, by providing a third polarized portion that vibrates in the same phase with the stretching vibration, the high-output ultrasonic motor may be realized because the stretching vibration is amplified. 
     According to the invention, by abutting the moving body to a piezoelectric vibrator in the horizontal direction, the moving body may be moved in the horizontal direction of the piezoelectric vibrator. 
     According to the invention, by abutting the laminated piezoelectric vibrator at least at one point of a spherical moving body of the ultrasonic motor, the spherical moving body may be moved arbitrary. 
     According to another aspect of the invention, an electronic apparatus using the ultrasonic motor may be realized. 
     While the preferred embodiments have been described, variations thereto will occur to those skilled in the art within the scope of the present inventive concepts which are delineated by the following claims.