JPH0677550A - Laminated piezoelectric element, manufacturing method thereof, polarization treatment method, and ultrasonic motor - Google Patents

Abstract

(57) [Summary] [Purpose] When disc-shaped piezoelectric elements are individually formed and subjected to polarization treatment, it takes time to perform polarization treatment or the piezoelectric ceramic requires a certain thickness. A laminated piezoelectric element that solves such a problem is provided. [Structure] A plurality of piezoelectric elements 4 in which electrode films 8-1 and 8-2 are formed on one surface side of a piezoelectric ceramic 5 with a slit 6 therebetween and an entire surface electrode film 10 is formed on the other surface side, The other surface side is staggered, and the slits 6 are laminated in the same direction so that the electrode films facing each other are in contact with each other, and the electrode films 8-1 and 8-2 are electrically conductive, respectively, and Conductive part 2 which is in a non-conductive state with each other
1, 2-2 and the conductive portion 3 in which the respective whole surface electrode films 10 are electrically conductive can be supplied with power.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated piezoelectric element, a manufacturing method thereof, a polarization treatment method thereof, and an ultrasonic motor.

[0002]

2. Description of the Related Art Already, for example, Japanese Patent Publication No. 3-40767.
The rod-shaped ultrasonic motor is described in Japanese Patent Publication No. 3-289375 and Japanese Patent Publication No. 3-289375. FIG. 10 is an exploded perspective view of a vibrator of the rod-shaped ultrasonic motor, and FIG. 11 is a vertical sectional view of the rod-shaped ultrasonic motor.

The vibrator shown in FIG. 10 has two piezoelectric elements P.
It is composed of a driving A-phase piezoelectric element a1 including ZT1 and ZT2 as one group, similarly a driving B-phase piezoelectric element a2 including two piezoelectric elements PZT3 and PZT4 as one group, and one piezoelectric element plate. Electrode plates A1, A for stacking the sensor piezoelectric elements s1 as shown in the drawing and for supplying electricity between these piezoelectric elements
2 and an electrode plate S for extracting the sensor signal. Further, together with them, the GND electrode plates G1, G2, G3 are also provided for applying the GND potential. Then, metal blocks b1 and b2, such as brass and stainless steel, having relatively small vibration damping are provided in front and back so as to sandwich these piezoelectric elements and electrode plates, and the metal blocks b1 and b2 are tightened by tightening bolts c to integrate them. Compressive stress is applied to the piezoelectric element. Further, at this time, an insulating sheet d is inserted between the bolt c and the metal block b2 in order to complete the single piezoelectric element for sensor s1.

At this time, the A-phase piezoelectric element a1 and the B-phase piezoelectric element a2 are arranged with a positional shift of 90 degrees, and each excites two perpendicular bending vibrations including the axis of the vibrator. And, by giving an appropriate time phase difference, a circular or elliptical motion is generated in the surface particles of the vibrator, and the moving body pressed against the upper part of the vibrator is frictionally driven.

An example in which such a vibrator is used in a rod-shaped ultrasonic motor is shown in FIG. In this example, the fastening bolt c of the vibrator has a small-diameter support portion c2 at its tip, and the fixing member g fixed to the tip of this support portion c2 enables the motor itself to be fixed. It also serves to support the rotation of the rotor r and the like. The rotor r contacts the front end surface of the front metal block b1, and the pressure is applied from the fixed member g through the bearing member e and the gear f to the spring case i installed in the rotor r.
It can be given by pressing the coil spring h. The piezoelectric element used for this rod-shaped ultrasonic motor will be described in more detail. One piezoelectric element PZT1 to PZT1 to PZT1 to PZT1-4 is formed by firing piezoelectric ceramics 5 made from powder as shown in FIG. The thickness is 0.5 mm, and two substantially semicircular electrode films 8-1 and 8 are formed on the surface through slits.
-2 is formed, and the electrode film 10 is formed on the entire back surface,
After that, the polarities of the semicircular electrode films 8-1 and 8-2 are polarized in the different directions (+) and (-) on the right and left to give piezoelectric characteristics. As shown in FIG. 10, for example, in the phase A, PZT1 and PZT2 are superposed so that the same polarities of polarization face each other across the electrode plate A1 and the slits overlap at the same time, as shown in FIG. . Similarly, the B phase is also overlapped. That is, as shown in FIG. 13, the direction of polarization of the A-phase piezoelectric element a1 is represented by an arrow 14, and when an AC voltage for driving is applied to the electrode plate A1, the piezoelectric element PZT1 and PZT2 will have a right side and a left side. When one is extended, the other is contracted, and this is alternately repeated to cause bending vibration in the oscillator. B-phase also causes bending vibration in the same state except that the orientation of the slit differs from that of the A-phase by 90 °.

[0006]

However, in the above-mentioned conventional example, since each piezoelectric element is pre-polarized and then laminated alternately with the electrode plates, a great deal of time is required for polarization. It also took time to assemble the vibrator. Furthermore, considering the handling at the time of the polarization treatment process and the assembly process of the piezoelectric element, it is necessary to increase the thickness of the piezoelectric ceramic to some extent in consideration of the strength, and as a result, the size of the entire element becomes large even if the number of layers is increased. For example, this is an obstacle to miniaturization of ultrasonic motors that can achieve ultra-miniaturization with a diameter approximately the same as or smaller than that of pencils. It was difficult.

It is an object of the present invention to provide a laminated piezoelectric element which solves the above conventional problems, a manufacturing method thereof, a polarization treatment method, and an ultrasonic motor using the laminated piezoelectric element.

[0008]

A laminated piezoelectric element, a method of manufacturing the same, a method of polarization thereof, and an ultrasonic motor that achieve the object of the present invention are as described in the claims, and specifically, in advance. Thin piezoelectric ceramics,
Polarization treatment of multiple piezoelectric elements can be performed by stacking multiple electrodes via the electrode film provided on the surface and making a laminated piezoelectric element by integrating the electrode films of each piezoelectric element without connecting them with a conductor. It is possible to perform the process in one polarization step, and further, it is possible to increase the number of stacked layers without increasing the size of the entire device.

[0009]

First Embodiment FIGS. 1 and 2 show a first embodiment of a piezoelectric element according to the present invention, and FIG. 3 shows its polarization treatment method. 1 (3) shows the AA cross section of (1), and (2) shows the BB cross section of (3).

Reference numeral 1 denotes a laminated piezoelectric element in which eight piezoelectric elements 4 are laminated. As shown in FIG. 2, the piezoelectric element 4 is formed by pre-calcining and then pulverizing powder and firing, and is machined into a disk shape. The piezoelectric ceramics 5 were screen-printed with silver paste on the front surface shown in FIG. 2 (1) and the back surface shown in FIG. 2 (2), respectively, and the slits of the diameter portion were formed on the front surface. Two semicircular electrode films 8-1 and 8-2 are formed on the outer peripheral side of the inner peripheral surface of the electrode 6, and the inner diameter side electrode film which is a portion where the electrode film is not formed is formed around the inner diameter portion. The forming portion 7 is formed, and on the other hand, the outer diameter side electrode film non-forming portion 9 which is a non-forming portion of the electrode film is formed along the outer peripheral portion on the back surface, and the electrode is spread over the entire inner diameter side. What formed the film 10 is used.

In this embodiment, the piezoelectric ceramic 5
Has a diameter of 10 mm, a thickness of 0.125 mm, an electrode film thickness of 3 to 5 μm, and a slit 6 width of 0.8 m.
m, the inner diameter side electrode film non-forming portion 7 and the outer diameter side electrode film non-forming portion both have a constant interval of 0.8 mm in width.

In the laminated piezoelectric element 1, the front surface and the back surface of the piezoelectric element 4 are opposed to each other, and the slits 6 are aligned and superposed, that is, the lowermost piezoelectric element 4 in this embodiment. Has the front side up, the second from the bottom has the back side up, the third from the bottom has the front side up, and so on.

At this time, the adhesive is evenly applied to the surfaces to be superposed, and after superposing, the temperature is raised to 60 ° C. while pressurizing with a press to make the adhesive as thin as possible and bring it into close contact to cure the adhesive. It was

Then, a paste made of an adhesive and silver is applied to the inner diameter side surface of the stacked piezoelectric elements to provide a conductive portion 3, and the outer diameter side surface is provided for each of the two semicircular electrode films of the piezoelectric element. Apply the same paste to the conductive parts 2-1 and 2-2.
Was formed. After application, the adhesive was completely cured by placing it in a constant temperature bath at a temperature of 60 ° C. for 2 hours.

The viscosity of the adhesive between the piezoelectric elements decreases once before the adhesive hardens, and at that time, pressure is applied by a press, so the electrode films 8-1, 8-2, 1 of the piezoelectric element 4 are pressed.
0s come into contact with each other to establish conduction. Furthermore, the viscosity of the conductive parts 2-1, 2-2, 3 attached to the inner and outer diameter side surfaces once decreases in the constant temperature bath and comes into contact with the electrode films 8-1, 8-2 and 10 of the respective piezoelectric elements. After that, it is cured and electrical continuity is obtained.

That is, the conductive portion 3 on the inner diameter side surface is every two layers,
Conductive portions 2-1 and 2-2 on the outer diameter side surface are electrically connected to the entire surface electrode film 10 applied to the back surface of each piezoelectric element, and the conductive portions 2-1 and 2-2 of the two semicircular shapes applied to the front surface of each piezoelectric element. Electrode film 8-1,
Each of them is connected to 8-2.

The position of the conductive portion 3 on the inner diameter side surface is not particularly limited, but the position of the conductive portions 2-1 and 2-2 on the outer diameter side surface vibrates when a laminated piezoelectric element is incorporated in a rod-shaped ultrasonic motor. Was set in the vicinity of the slit 6 so as not to disturb the above. In addition, when the stacked piezoelectric elements are pressed and bonded, the adhesive will slightly stick out to the inner and outer diameter side surfaces of the piezoelectric element.Before applying the paste to form the conductor parts on the inner and outer diameter side surfaces, In advance, the adhesive on the applied part was scraped off in advance. The conductive portions 2-1, 2-2 and 3 are each 10 to 20 μm thick and about 1 mm wide. The method of forming the electrode film and the conductive portion includes vapor deposition, electroless plating and the like other than this example, but there is no particular problem even if these are used, so reliability,
It should be decided considering productivity and cost.

Next, the laminated piezoelectric element thus produced is connected by using high resistance 122 pieces of 100 MΩ as shown in FIG. 3 so as to divide the voltage, and the contact pin 11 is connected to the conductive portions 2-1 and 2-1. 2-2 and the electrode film 10 were contacted. Then, a DC voltage of 320 V was applied for 60 minutes by the DC power supply 13 to perform polarization treatment in a 120 ° C. constant temperature bath. In the connection shown in FIG. 3, the electrode film 8-1 electrically connected to the conductive portion 2-1 is 0.
With V, 160 V can be applied to the electrode film 10 that is electrically connected to the conductive portion 3, and 320 V can be applied to the conductive portion 8-2. This results in arrow 1
It is polarized in four directions. Since the polarization direction is as described above, GND is connected to the conductive portion 3 or the electrode film 10, and the conductive portion 2-
If an AC voltage, which is a drive voltage for the rod-shaped ultrasonic motor, is applied to 1 and 2-2, as described in the conventional example, AA in FIG.
Expansion and contraction are repeated alternately on the left and right sides of the cross section.

Conventionally, for example, in the polarization treatment of a piezoelectric element having a thickness of 0.5 mm, it is necessary to apply a voltage of 1.0 to 1.5 kV, and at such a voltage, dielectric breakdown occurs in the air, so that it is usually It is carried out in insulating oil. In this laminated element, the thickness of one piezoelectric element is thin, and therefore the voltage for polarization can be lowered to about 300 V, and polarization treatment in air is possible.

This has the great advantage that the stacked piezoelectric elements can be polarized at one time, and washing and drying after using the insulating oil are not necessary, which facilitates the polarization treatment.
Before polarization, the electric resistance between the conductive parts on the inner and outer diameter side surfaces was measured at a measuring voltage of 250 V, and was 2000 MΩ or more, and the insulation between the conductive parts and the electrode films was good. Further, when the electrostatic capacitance (1 kHz) between the conductive portion 3-electrode film 10 and the conductive portions 2-1 and 2-2 on the two outer diameter side surfaces was compared before and after polarization, the increase was 20 to 30% or more. It was also confirmed that it was polarized. In addition, when polarization is performed, soldering or the like may be performed as long as conduction can be established in addition to the contact pin 11. The polarization condition is voltage,
It is related to temperature and time, and is not particularly limited to the conditions of this example.

The above is an example of production using the piezoelectric ceramics after firing. Next, an example of production from a green sheet will be described.

First, pulverized powder after calcination for producing piezoelectric ceramics, an organic binder and water were sufficiently mixed and molded into a sheet by an extrusion molding machine. The formed sheet is punched using a punching press, and the punched sheet has the same electrode pattern 8-
1, 8-2 and 10 were screen-printed with a platinum conductive paste to form electrode films. Then, as described above, they were superposed, and pressure was applied by a press while heating to integrate them. Further, as in FIG. 1, conductive portions 2-1 to 2-2 and 3 were formed on the outer peripheral side and the inner peripheral side with a conductive paste of platinum. In this state, firing in a lead atmosphere at about 1200 to 1300 ° C. made a fired laminated piezoelectric element similar to that shown in FIG.

The polarization treatment was performed under the same conditions as described above. In addition,
Since shrinkage is caused by firing after lamination, the size of the sheet was set to 0.150 mm and the thickness of the electrode film was set to 5 to 6 μm in consideration of shrinkage. As described above, the manufacturing methods include a method of stacking and stacking piezoelectric ceramics produced by sintering and a method of stacking and stacking green sheets before sintering, but the final method depends on reliability and cost during production. You should decide the method.

Next, an example in which the laminated piezoelectric element manufactured as described above is incorporated in a rod-shaped ultrasonic motor will be described.

In the eight-layer laminated piezoelectric element 1 of FIG. 3 of this example, the electrode film 10 on the back surface of the piezoelectric element 4 which is conducted by the conductive portion 3 is exposed at both ends of the upper and lower surfaces, and the GND surface (G) is obtained. Is formed. Therefore, when it is used by incorporating it into a rod-shaped ultrasonic motor, the conductive parts 2-1 and 2-2 on the outer diameter side surface have the same potential,
Since a drive voltage is applied and used, the conductive parts 2-1 and 2-2 are electrically connected to each other by a paste containing the above-mentioned adhesive and silver powder before use.

In FIG. 5 (1), two laminated piezoelectric elements 1 according to the present invention are actually incorporated in a vibrator with the slits intersecting the A phase and B phase of the vibrator at 90 °. Since both ends of the laminated piezoelectric element 1 are GND planes (G), the electrode plates G2 and G3 in the conventional example of FIG. 10 are not necessary.
Further, in order to supply a driving voltage, the lead wires 15 and 16 are directly soldered to the conductive portion 2-1 on the outer diameter side surface of the laminated piezoelectric element 1. Therefore, the electrode plates A1 and A2 are no longer needed.

Further, the image pickup device may be prepared in advance by stacking two laminated piezoelectric elements corresponding to (1) a1 and a2 in FIG. 5 so that the slits intersect at 90 °.
In this case, the conductive parts 3 corresponding to a1 and a2 are made conductive,
After conducting the conductive parts 2-1 and 2-2, the polarization process can be performed as described above. Then, when the motor is driven, the conductive parts 2-1 and 2-2 are switched from the conductive state to the insulated state, and this time, the conductive parts 2-1 and 2-2 corresponding to a1 and a2 are brought into conduction, and the conductive part 2 A drive voltage may be applied by connecting a lead wire to -1.

The above example is an example in which eight layers are stacked, and the same is true in the case of an even-numbered layered piezoelectric element. However, for example, as shown in FIG. When the device is used by incorporating it into a rod-shaped ultrasonic motor,
On the upper and lower end surfaces of the laminated piezoelectric element 1 ', the GND surface (G) having the electrode films 10 conducted by the conductive portion 3', and the conductive portion 2'-
The drive potential surface (A) for supplying a drive voltage to the electrode films 8-1 and 8-2 which are electrically connected at 1 and 2'-2 is formed.

When such a laminated piezoelectric element 1'is actually used by incorporating it in the A and B phases of a vibrator, the slits of the A phase and the B phase are made to intersect each other by 90 °, and (2) in FIG.
As described above, the insulating sheet d2 was inserted between the laminated piezoelectric elements 1 ′ so that the GND surfaces (G) of the two laminated piezoelectric elements 1 ′ were in contact with the electrode plates G1 and G3 to conduct electricity. On the other hand, the drive voltage was applied by directly soldering the lead wires 15 and 16 to the conductive portion 2-1 on the outer diameter side surface. In addition, if the method is adopted in which the lead wire is not directly connected to the side surface of the laminated piezoelectric element 1 ′, the method shown in FIG.
As in (3), the electrode plates A1 and A2 can be used, and further, the laminated piezoelectric element 1'can be used by incorporating it in the rod-shaped ultrasonic motor by using two pieces each for the A and B phases, for a total of four pieces. In this case, it is not necessary to short-circuit the conductive parts 2-1 and 2-2 on the outer diameter side surface of the laminated piezoelectric element. As described above, when the present laminated piezoelectric element is used, it is possible to reduce the number of electrode plates that have been alternately stacked in the related art, and the assembly is facilitated.

In the embodiments described above, the conductive portion connecting the electrode films between the piezoelectric elements is provided on the outer diameter side surface for the two semicircular electrode films on the front surface of the piezoelectric element, and the inner diameter for the electrode film on the back surface. Although provided on the side surface, each conductive portion is not limited to the inner and outer diameter side surfaces. For example, as shown in FIG. 6, an electrode film to be formed on the piezoelectric ceramics 5 is provided on the front surface with a portion 7'having no electrode film at a constant interval on the outer diameter side, and on the back surface with a constant electrode portion on the inner diameter side. By providing the portions 9'without the electrode film at intervals, the conductive parts 2'-1, 2'- connecting the two semi-circular electrode films on the surface respectively after superimposing and integrating. 2 may be provided on the inner diameter side surface, and the conductive portion 3 ′ connecting the electrode films on the back surface may be provided on the outer diameter side surface.

As another example, as shown in FIGS. 7 and 8, on the back surface of the piezoelectric element 4, a portion not attached to the electrode film on the outer diameter and the inner diameter side is formed on the back side of the slit 6 on the front side from the slit 6. Piezoelectric elements are stacked by laminating the narrow electrode film 10 ', aligning the directions of the slits, and stacking the conductive elements 2-1, 2-2, 3'only in the outer diameter side fixed. , Fig. 8
Then, the conductive portions 2′-1, 2′-2, and 3 are provided only on the inner diameter side surface. In any case, the conductive portions connecting the electrode films are not limited to the locations where the conductive portions are formed as long as the insulation between the conductive portions is maintained. Also when using these laminated piezoelectric elements incorporated in an ultrasonic motor, a method of connecting a lead wire to the outer diameter side surface of the element or a method of using electrode plates in contact with both end surfaces has been considered. The electrode film, which is the back surface of the piezoelectric element, is grounded, and
If a drive voltage can be applied to the two electrode films, there is no problem.

The above description has been made on the case of the rod-shaped ultrasonic motor using the drive voltages of the two tanks of A phase and B phase. Furthermore, a case where the rod-shaped ultrasonic motor is driven by a three-phase driving voltage having a phase difference of 120 ° can be considered. For example, in (1) of FIG. 5 already described, the three laminated piezoelectric elements are arranged such that the directions of the slits are displaced by 120 °, the respective elements are connected by lead wires, and a three-phase drive voltage is applied. By doing so, circular or elliptical motion can be generated in the surface particles of the oscillator, as in the case of two phases.

When the three phases are used, the voltage applied to the piezoelectric element can be made substantially larger than that of the two phases, the movement of the oscillator can be increased, and the performance of the motor is improved.

FIG. 9 shows a driving device using a rod-shaped ultrasonic motor incorporating the laminated piezoelectric element 1 according to the present invention.

The basic structure of this rod-shaped ultrasonic motor is shown in FIG.
0 is different from the conventional example in that the laminated piezoelectric element 1 is used, and the gear f assembled integrally with the ultrasonic motor meshes with the input gear GI of the gear transmission mechanism G. The output gear GO meshes with the gear HI formed on the lens holding member H that holds the lens L1. The lens holding member H is helicoidally coupled to the fixed barrel K, and is rotationally driven by a driving force of an ultrasonic motor via a gear transmission mechanism G to perform a focusing operation.

[0036]

As described above, by using a laminated piezoelectric element in which a plurality of thin piezoelectric elements capable of polarization treatment in a laminated state are stacked, a rod-shaped ultrasonic motor can be downsized, increased in output, and lowered. Not only can it be driven by a voltage, but the polarization process of the piezoelectric element can be facilitated, and the piezoelectric element can be assembled accurately in a short time even when assembling the ultrasonic motor.

In addition, in the laminated piezoelectric element thus formed, one piezoelectric ceramic can be made thin in addition to being multi-layered, and as a result, the electrostatic capacity becomes large, and the input impedance becomes small when used as a motor, and only that much input is made. Since power can be supplied, it has characteristics suitable for low voltage driving and high output.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a laminated piezoelectric element of the present invention.

FIG. 2 is a diagram showing one piezoelectric element that constitutes the laminated piezoelectric element of FIG.

3 is a diagram showing a polarization treatment method for the laminated piezoelectric element shown in FIG.

FIG. 4 is a diagram showing another embodiment of the laminated piezoelectric element of the present invention.

FIG. 5 is a diagram showing a state in which a laminated piezoelectric element is incorporated in a rod-shaped ultrasonic motor.

FIG. 6 is a diagram showing another embodiment of the laminated piezoelectric element of the present invention.

FIG. 7 is a diagram showing another embodiment of the laminated piezoelectric element of the present invention.

FIG. 8 is a diagram showing another embodiment of the laminated piezoelectric element of the present invention.

9 is a cross-sectional view of a lens barrel incorporating a lens driving mechanism that uses an ultrasonic motor having the laminated piezoelectric element of FIG. 1 as a driving source.

FIG. 10 is an exploded perspective view of a vibrator of a conventional rod-shaped ultrasonic motor.

FIG. 11 is a sectional view of a conventional rod-shaped ultrasonic motor.

FIG. 12 is a diagram showing a piezoelectric element for a conventional ultrasonic motor.

FIG. 13 is a diagram showing the relationship between the polarization direction and expansion / contraction direction of a piezoelectric element.

[Explanation of symbols]

1, 1 '... laminated piezoelectric element 2-1, 2-2, 3, 2'-1, 2'-2, 3' ... conductive part 4 ... piezoelectric element 5 ... piezoelectric ceramic 6 ... slit 7, 9 ... electrode film Unformed part 8-1, 8-2, 10 ... Electrode film

Claims (5)

[Claims] 1. A plurality of piezoelectric elements each having a plurality of divided electrode films formed on one surface side and an entire surface electrode film formed on the other surface side, wherein one surface side and the other surface side are staggered and each divided electrode is formed. A plurality of conductive parts that are stacked so that the electrode films facing each other are in contact with each other so that the phases of the films are in contact with each other, and that the divided electrode films having the same phase are made conductive in the stacking direction and are in a non-conductive state with respect to each other. And a conductive portion in which the respective full-surface electrode films are electrically connected to each other, and power is supplied to each of the conductive portions. 2. A plurality of piezoelectric elements in the laminated piezoelectric element according to claim 1, wherein a divided electrode film and an entire surface electrode film are formed in advance on a fired piezoelectric ceramic, and the plurality of piezoelectric elements are bonded by an adhesive. A method for manufacturing a laminated piezoelectric element, which comprises heating the adhesive in a laminated and pressurized state to cure the adhesive. 3. A plurality of piezoelectric elements in the laminated piezoelectric element according to claim 1, wherein a piezoelectric ceramic material in a sheet-like kneaded state before firing is punched into a predetermined shape, and electrode films are formed on both front and back surfaces thereof. Then, the laminated piezoelectric element is formed by laminating the layers and heating them while applying pressure. 4. A polarization treatment method for a laminated piezoelectric element, comprising applying a DC voltage to each conductive portion of the laminated piezoelectric element according to claim 1 and performing the polarization treatment while heating in air. 5. A plurality of laminated piezoelectric elements according to claim 1 having a predetermined phase are sandwiched and fixed between metal blocks, and an AC voltage having a predetermined phase is applied to these laminated piezoelectric elements, A rod-shaped oscillator that forms an elliptical or circular motion on the surface particles of the metal block; and a moving body that is frictionally driven by the elliptical or circular motion by being in pressure contact with the oscillator. Sonic motor. 5. An apparatus using the ultrasonic motor according to claim 5 as a drive source.