CN101001055A - Piezoelectric actuator drive control method, piezoelectric actuator drive control apparatus, and electronic device - Google Patents

Abstract

A piezoelectric actuator drive control method, piezoelectric actuator drive control device, and electronic device greatly reduce power consumption. The piezoelectric actuator drive control device stores as a speed setting the minimum speed at which a rotor (driven body) turns when driven by the minimum torque required to turn the rotor (S 10 ), and to achieve this speed setting limits the pulse width of the drive signal relative to the reference pulse width of a reference signal (S 20 ). By limiting pulse width to the minimum pulse width required to drive the rotor, the pulse duty of the drive signal in a rectangular wave drive pulse train can be reduced and power consumption can be reduced greatly compared with a drive signal having a 100% pulse duty when the pulse width is not limited. Battery life can therefore be increased.

Description

Drive controlling method, driving control device and the electronic equipment of piezo-activator

Technical field

The present invention relates to drive controlling method, piezoelectric actuator drive control device and the electronic equipment of piezo-activator.

Background technology

Piezoelectric element is because good to the conversion efficiency of mechanical energy and response etc. from electric energy, so developing piezo-activator (ultrasonic motor) in recent years, it comprises the vibrating body with piezoelectric element, and the transfer of vibration of this vibrating body is driven to driven members such as rotors.

And, known the piezo-activator that adopts resonance, because good aspect small-sized, slim, high torque (HT), think to be increased in installation on the various portable sets etc. from now on.

The drive controlling of this piezo-activator is carried out (for example patent documentation 1) by the drive signal that square-wave voltage alternately is provided to piezoelectric element usually.In patent documentation 1, the magnification ratio of change amplifying circuit changes the voltage that applies to piezo-activator, suppresses the electric current of piezo-activator thus.

No. 2506895 communique of [patent documentation 1] Japan special permission (the 4th page You Lan stage casing, Fig. 5)

But, when utilizing common rectangular wave pulse signal to drive, show 100% duty ratio driving greatly with respect to the benchmark pulsewidth, still, because the output of piezo-activator generally is set considerably beyond needed torques such as driving rotors, so cause power wastage.The problem that has shorter battery life thus.

, suppress electric current even adjust the voltage of drive signal as patent documentation 1 herein, in the structure that can change voltage, because circuit efficiency reduces, so also can cause consumption more high-power, the result can not realize power saving effect.

Summary of the invention

The present invention finishes in view of the above problems, and its purpose is, a kind of drive controlling method, piezoelectric actuator drive control device and electronic equipment that can especially reduce the piezo-activator of power consumption is provided.

The drive controlling method of piezo-activator of the present invention, the vibrating body that provides drive signal to vibrate by to piezoelectric element is provided this piezo-activator, and give driven member with the transfer of vibration of described vibrating body, it is characterized in that, described vibrating body is according to the supply of square wave and single-phase described drive signal, synthesis mode vibration with a plurality of vibration modes, described piezo-activator is to realize the benchmark pulsewidth of the determined maximum driving force of drive characteristic when driving described driven member, produce described drive signal, with respect to described benchmark pulsewidth, to realize that the minimum pulse width in order to drive the needed MIN minimum actuating force of described driven member according to described drive characteristic is a limit, limit the pulsewidth of described drive signal.

According to the present invention, with respect to the benchmark pulsewidth, the pulsewidth of drive signal is restricted to the degree that can drive driven member, and the result can reduce the pulse duty factor of drive signal in rectangular wave drive.Therefore, even the output of piezo-activator is set to high output, make that considerably beyond the ratio in the pulsewidth relative datum pulsewidth of drive signal be needed torque in 100% o'clock, also can be by the pulsewidth of restriction drive signal, output is reduced to can the actual degree that drives driven member, so compare with pulse duty factor 100% (ratio of the pulsewidth relative datum pulsewidth of drive signal the is 100%) time that does not have pulsewidth restriction, can especially accomplish low-power consumption.Therefore, when the power supply of piezo-activator uses battery, extending battery life significantly.

Herein, the benchmark pulsewidth of drive signal is set to the maximum pulse width (Duty100%) that realizes maximum driving force in the drive characteristic of piezo-activator.Maximum driving force waits to determine according to the inertia of the desired output of piezo-activator, driven member and the pressurized conditions of driven member and driving body.

In addition, the actuating force of regulation can be held amount of movement (being rotating speed etc. during rotary body) for driven member, flow through the current value of piezoelectric element or piezo-activator etc.

And, by providing single-phase drive signal, make this vibrating body with the vibration of the synthesis model of a plurality of vibration modes to vibrating body as the drive controlling object, so compare when using heterogeneous drive signal, can accomplish simplified structure and realize power saving.

In addition, when the pulse of drive signal is restricted to minimum pulse, can realizes driving the purpose of driven member according to the output of the minimum actuating force of piezo-activator, and power consumption is suppressed to the limit.That is, more favourable in occasion that irrespectively drives driven member simply with actuating speed etc.

In the drive controlling method of piezo-activator of the present invention, preferably more hour, will limit more for a short time herein, with respect to the pulsewidth of the described drive signal of described benchmark pulsewidth in the regulation actuating force that described driven member is moved.

In this structure, the regulation actuating force that driven member is moved is more little, can promote low-power consumption more.In other words, when driven member is rotary body, can increase the low-power consumption effect in the low speed rotation zone.

And, so more hour in the actuating force of regulation, to limit more for a short time with respect to the pulsewidth of the described drive signal of described benchmark pulsewidth, thus under the situation that for example driven member quickens when driven member starts etc., also can be in the pulsewidth of the initial velocity after the corresponding starting of being restricted to of this acceleration midway, so can reduce power consumption.

For example, in the drive controlling of the piezo-activator that drives indicating devices such as the pointer of clock and watch, swivel plate, as this accelerated motion, the fast commentaries on classics the when F.F. of reset (returning zero) action, the store energy pointer of the pointer of can supposing to clock, alarm settings etc.Thisly clock, in the clock and watch of store energy and alarm settings etc., think the drive controlling that adopt this structure more having.

, when carrying out this action, can drive herein,, can prevent rapid acceleration and deceleration by the roughly integral body in driving so driven member can not be applied in the braking that forms because of the wearing and tearing with piezo-activator with less pulsewidth (with low duty ratio).Thus, can reduce the wearing and tearing of the abutment portion between piezo-activator and the driven member.

In the drive controlling method of piezo-activator of the present invention, preferred described vibrating body forms roughly rectangular shape when overlooking, and described a plurality of vibration modes of described vibrating body are along the flexible extensional vibration of the length direction of described vibrating body and the flexural vibrations of relative described length direction bending.

According to the present invention, can realize the elliptic motion of vibrating body part according to the phase difference of extensional vibration and flexural vibrations, so, can drive rotor etc. expeditiously by vibrating body though be based on the simple type of drive of single-phase drive signal.

In the drive controlling method of piezo-activator of the present invention, preferably scan the pulsewidth of described drive signal, obtain the suitable pulsewidth of the actuating force that realizes described regulation, described drive signal is controlled to be described suitable pulsewidth.

According to the present invention, can obtain suitable pulsewidth according to actual measurement, the drive signal Be Controlled must become this suitable pulsewidth, so can reliably obtain desired actuating force.

In the drive controlling method of piezo-activator of the present invention, preferably when starting with the pulsewidth initialization of the suitable pulsewidth of the actuating force that realizes described regulation with described drive signal.

According to the present invention, compare when being made as " 0% " etc. with initial value with pulsewidth, the approaching actuating force of actuating force that can obtain originally and stipulate in starting, driven member becomes stable state as early as possible, so can realize low-power consumption and can not influence priming speed.

In the drive controlling method of piezo-activator of the present invention, preferably, determine described suitable pulsewidth based on the pulsewidth of the described drive signal of described driven member when becoming stable state when the driving of last time starting.

According to the present invention,, upgrade suitable pulsewidth, so can optimize actuating force and power consumption according to the change etc. of load according to the stable state when the driving of last time starting.

Herein, the stable state in the time of also can be according to the driving of last time starting is upgraded suitable pulsewidth when each starting.

And the pulsewidth of the described drive signal that suitable pulsewidth also can be so that each when starting when repeatedly starting, described driven member becomes stable state is that the basis is determined.

By obtaining the average of several, suitable pulsewidth is optimised, can further optimize actuating force and power consumption like this.

In the drive controlling method of piezo-activator of the present invention,, adjust the pulsewidth of described drive signal preferably according to the detection of the driving condition of this piezo-activator.

According to the present invention, corresponding driving condition carries out drive controlling, so even when change such as load, also can the stabilized driving driven member.

Herein, the driving condition of the so-called piezo-activator that detects in order to adjust pulsewidth waits to determine according to the amount of movement of the driven members such as rotating speed of current value that flows through piezo-activator and rotor.

And, stabilized driving when realizing driving driven member with fixing speed, not only when detecting the driving condition of this piezo-activator, under the situation that the amount of movement of controlling driven member can change, for example, the current instruction value that also can have current detector, the fixing speed of piezo-activator produces the source and comes control flows to cross the controller of the current value of piezo-activator according to current value that is detected and current instruction value, pulsewidth is adjusted in output according to controller, carries out speed control thus.Under this situation, when each speed, set the minimum pulse width and the maximum pulse width that can drive driven member respectively, according to the pulsewidth of top described relative datum pulse width control drive signal.Certainly, also can replace this control that detects based on current value, and the controller that the amount of movement command value with detector, fixing speed of the amount of movement that detects driven member produces the source and controls amount of movement according to the amount of movement that is detected and command value, thereby the adjustment pulsewidth can also be adjusted pulsewidth according to current value and driven member amount of movement both sides' detected value.

In the drive controlling method of piezo-activator of the present invention, preferably except the actuation step of the pulsewidth that limits described drive signal with respect to described benchmark pulsewidth, also comprise the initial setting step, this initial setting step has: the optimum phase difference obtaining step, it is about described drive signal and represent phase difference between the detection signal of described detected driving condition, implement the frequency scanning of described drive signal, obtain optimum phase difference as the phase difference of the driving condition of realizing regulation; The phase difference counter-rotating detects step, it detects the phase difference between described drive signal and the described detection signal, in the prescribed limit of the frequency that comprises the driving condition of realizing described regulation, implement simultaneously the frequency scanning of described drive signal along prescribed direction, at this moment, phase difference reversal frequency when detecting described phase difference and reaching described optimum phase difference once more, in described actuation step, limit according to described phase difference reversal frequency, make the frequency of described drive signal can not reach the clamp frequency that in the value of the driving condition side of described regulation, sets, detect the phase difference between described drive signal and the described detection signal simultaneously, and according to described phase difference with respect to described optimum phase extent, change to the frequency of described drive signal high or low, make the frequency of described drive signal follow described phase difference thus, frequency with regulation carries out described initial setting step, upgrades described optimum phase difference and described phase difference reversal frequency respectively.

According to the present invention, optimum phase difference at the driving condition that is used to realize stipulate, the variation of the pressurized conditions that reason forms in the pressurization individual difference of vibrating body and driven member and wearing and tearing etc., when perhaps the variations in temperature that forms owing to the Continuous Drive of piezo-activator etc. changes, also can in initial setting, obtain optimum phase difference with the regulation frequency, optimum phase difference is updated and is corrected as suitable optimum phase difference, so can implement suitable drive controlling according to this optimum phase difference, can realize desired driving efficient with the needed appropriate drive power of the driving of driven member (torque).

In addition, the regulation frequency for example according to somewhat～waited each constant in several hours during or the number of starts of piezo-activator, the number of times that carries out specified action wait to determine.

In addition, also implementing the phase difference counter-rotating in initial setting detects.That is,, detect the frequency when producing the phase difference counter-rotating, so the phase difference reversal frequency is also followed the renewal of optimum phase difference and upgraded for the optimum phase difference of in initial setting, be initialised (renewal).

Herein, it is synthetic etc. that tentatively phase difference reversal development can think results from the phase place of the various vibrations under a plurality of vibration modes of sum of errors in the vibrating body assembling, and Figure 30 represents this phase difference reversal development.In this Figure 30, can realize desired vibration characteristics according to optimal drive state G, during with Rack turntable driving frequency, there is the rollback point Pt that reaches the target phase difference θ under the optimal drive state G once more in prescribed direction.During this situation, front and back at this rollback point Pt, follow direction counter-rotating (the following counter-rotating, reversal development that this situation is called phase difference etc.) based on the driving frequency of the relative target phase extent of phase difference, with the driving that comprises optimal drive state G among the adjacent scope U2 of the driving scope U1 that uses, with respect to the phase difference of target phase difference θ big (+), so being changed to the opposite direction of proper orientation, driving frequency promptly increases direction, so that phase difference is near target phase difference θ.Therefore, cause drive controlling extremely unstable.

As countermeasure at this phase difference reversal development, drive controlling method of the present invention has the phase difference counter-rotating and detects step, specifically, detect in the step in this phase difference counter-rotating, detect the phase difference between drive signal and the detection signal, implement the scanning of driving frequency simultaneously, this moment, detected phase contrast reversal frequency was as the frequency of the counter-rotating that produces phase difference when phase difference reaches optimum phase difference once more.And, during drive controlling after carrying out initial setting, in order to prevent that phase difference is with respect to the counter-rotating of optimum phase extent and limit driving frequency, and the frequency that makes drive signal is followed the control of phase difference, serves as the clamp frequency that the basis is set so that the frequency of drive signal can not reach with the phase difference reversal frequency.Thus, can prevent that driving frequency from being changed to reciprocal abnormality processing because of the reversal development relevant with the phase difference evaluation, can stably implement drive controlling.In addition, phase difference reversal frequency and clamp frequency also can be mutually the same.

By above processing, since wearing and tearing etc. through the time change and variations in temperature etc. produces resonance point and optimum phase difference changes and as the vibration characteristics of piezo-activator during in frequency scanning under the situation of phase difference counter-rotating correspondence well.Therefore, no matter the driving time of the environment for use of piezo-activator and piezo-activator etc. can both further enlarge the scope of application (can long-time continuous drive) of piezo-activator, can improve reliability and reduce cost.

Piezoelectric actuator drive control device of the present invention, the vibrating body that provides drive signal to vibrate by to piezoelectric element is provided this piezo-activator, and give driven member with the transfer of vibration of described vibrating body, it is characterized in that, described vibrating body is according to the supply of square wave and single-phase described drive signal, synthesis mode vibration with a plurality of vibration modes, this piezoelectric actuator drive control device has: source driving signal, it makes described piezo-activator to realize the benchmark pulsewidth of the determined maximum driving force of drive characteristic when driving described driven member, produce described drive signal, and control part, it is with respect to described benchmark pulsewidth, to realize that the minimum pulse width in order to drive the needed MIN minimum actuating force of described driven member according to described drive characteristic is a limit, limit the pulsewidth of described drive signal.

According to the present invention, with respect to the benchmark pulsewidth, the pulsewidth of drive signal is restricted to the degree that can drive driven member, can reduce the pulse duty factor of drive signal in rectangular wave drive, so can especially accomplish low-power consumption.

And, by providing single-phase drive signal, make this vibrating body with the vibration of the synthesis model of a plurality of vibration modes to vibrating body as the drive controlling object, so compare when using heterogeneous drive signal, can accomplish simplified structure and realize power saving.

In addition, when the pulse of drive signal is restricted to minimum pulse, can realizes driving the purpose of driven member according to the output of the minimum actuating force of piezo-activator, and power consumption is suppressed to the limit.

In piezoelectric actuator drive control device of the present invention, preferred described vibrating body forms roughly rectangular shape when overlooking, and described a plurality of vibration modes of described vibrating body are along the flexible extensional vibration of the length direction of described vibrating body and the flexural vibrations of relative described length direction bending.

According to the present invention, can realize the elliptic motion of vibrating body part according to the phase difference of extensional vibration and flexural vibrations, so, can drive rotor etc. expeditiously by vibrating body though be based on the simple type of drive of single-phase drive signal.

In piezoelectric actuator drive control device of the present invention, preferably has the storage part of the suitable pulsewidth of storing the actuating force that realizes described regulation.

According to the present invention, in storage part, preserve suitable pulsewidth, so for example when starting, can during this situation, can realize low-power consumption and can not influence priming speed with of the pulsewidth initialization of this suitable pulsewidth with drive signal.

In addition, for example also can in driving, obtain suitable pulsewidth again, upgrade the value be kept at the suitable pulsewidth in the storage part, can carry out suitable drive controlling according to the change of load etc. thus, can make to drive to become stable.In addition, the renewal of suitable pulsewidth can be carried out with the regulation frequency of stipulated time and stipulated number etc.

In addition, when driven member is in stable state and the pulsewidth of the drive signal during proceed-to-send as suitable pulsewidth, be kept in the storage part, can when the driving of starting next time, determine the initial value of drive signal thus according to the suitable pulsewidth of this storage.Thus, can optimize actuating force and power consumption.

In addition, also can in this storage part, preserve the regulation that expression uses during drive controlling actuating force driven member amount of movement (during rotary body as rotating speed etc.), flow through the current value of piezoelectric element or piezo-activator etc.

In piezoelectric actuator drive control device of the present invention, preferably have the test section of the driving condition that detects this piezo-activator, described control part is adjusted the pulsewidth of described drive signal according to described driving condition.

According to the present invention, corresponding driving condition carries out drive controlling, so even when change such as load also can stably drive driven member.

In piezoelectric actuator drive control device of the present invention, preferably include: initial setting section, it has: phase difference detection portion, detect described drive signal and expression by the phase difference between the detection signal of the driving condition that described test section detected; The optimum phase difference acquisition unit is implemented the frequency scanning of described drive signal, according to the detection of described phase difference detection portion to described phase difference, obtains the optimum phase difference as the phase difference of the driving condition of realizing regulation; With phase difference counter-rotating test section, detect the phase difference between described drive signal and the described detection signal, in the prescribed limit of the frequency that comprises the driving condition of realizing described regulation, implement simultaneously the frequency scanning of described drive signal along prescribed direction, phase difference reversal frequency when at this moment, detecting described phase difference and reach described optimum phase difference once more; FREQUENCY CONTROL portion, it sets the frequency of described drive signal according to described optimum phase difference; And frequency control part, its frequency with regulation carries out the processing of described initial setting section, thereby upgrade described optimum phase difference and described phase difference reversal frequency respectively, described FREQUENCY CONTROL portion has clamp portion, this clamp portion limits according to described phase difference reversal frequency, make the frequency of described drive signal can not reach the clamp frequency that in the value of the driving condition side of described regulation, sets, described FREQUENCY CONTROL portion implements the frequency limitation of described clamp portion to described drive signal, detect described phase difference by described phase difference detection portion simultaneously, and according to described phase difference with respect to described optimum phase extent, the frequency of described drive signal is changed to high or low, make the frequency of described drive signal follow described phase difference thus.

According to the present invention, can in initial setting, upgrade optimum phase difference and phase difference reversal frequency respectively, so since wearing and tearing etc. through the time change and variations in temperature etc., when resonance point and optimum phase difference change, drive controlling also can be stablized, and when during in frequency scanning under the situation of phase difference counter-rotating, driving frequency also not occurring and be changed to reciprocal unusual control as the vibration characteristics of piezo-activator.That is,, can also realize stable drive controlling except aforementioned low-power consumption of the present invention.

Electronic equipment of the present invention is characterised in that this electronic equipment has: piezo-activator; The driven member that is driven by this piezo-activator; And the piezoelectric actuator drive control device of narrating previously.

According to the present invention,, can realize as hereinbefore effect and effect by having the piezoelectric actuator drive control device of narrating previously.

That is, can accomplish to realize the long-life of battery in the low-power consumption especially, the particularly portable set that moves utilizing battery.

In addition, as electronic equipment, all right exemplary portable formula phone, portable data assistance, touchable toy, camera, printer etc.

In electronic equipment of the present invention, preferably this electronic equipment is to have timing portion and show clock and watch by the clocking information display part of the clocking information of described timing portion timing.

According to the present invention, can utilize aforementioned piezo-activator to drive gear that constitutes timing portion and the indicating device that constitutes the clocking information display part etc. with low-down power consumption, and the minimizing of the replacing frequency of battery, so can improve convenience.

In addition, can realize the advantage of piezo-activator, promptly not be subjected to the influence of magnetic, response is higher, can carry out small quantity and send to, helps small-sized slimming, realizes high torque (HT) etc.

In addition, aforementioned piezoelectric actuator drive control device can utilize hardware to realize, also can use control program to realize.

In this control program, as long as make the computer that is assemblied in the aforementioned driving control device bring into play the effect of detecting unit, control part, phase difference detection portion, initial setting section, FREQUENCY CONTROL portion, frequency control part etc.

If form this structure, can bring into play the action effect identical with aforementioned driving control device.

Herein, this control program can also can be installed by the computer-readable storage medium of having stored this program by installations such as networks on computers.

If this control program that provides by communication units such as recording medium and internets etc. is installed on clock and watch and the portable set, then only can realize aforementioned action effect, also can or select the control program of user expectation to install when product export by altering the procedure.During this situation, only can different various clock and watch and the portable sets of production control mode by altering the procedure, so can realize the shared etc. of parts, the manufacturing cost in the time of can significantly reducing model extension.

According to the present invention, can reduce power consumption extraordinarily, battery life is prolonged.

Description of drawings

Fig. 1 is the outside drawing of the clock and watch of the 1st execution mode of the present invention.

Fig. 2 is the vertical view of the device displaying calendar date in the described execution mode.

Fig. 3 is the stereogram of the piezo-activator unit in the described execution mode.

Fig. 4 is the vertical view of the piezo-activator unit in the described execution mode.

Fig. 5 is the block diagram of the structure of the piezoelectric actuator drive control device in the described execution mode of expression.

Fig. 6 is the curve chart of the relation of (A) driving frequency of the vibrating body of expression in the described execution mode and impedance, (B) curve chart of the relationship of amplitude of driving frequency and extensional vibration and flexural vibrations.

Fig. 7 is the curve chart of the drive characteristic the during pulsewidth of scanning drive signal in the described execution mode of expression.

Fig. 8 is the flow chart of drive controlling of the piezo-activator of the described execution mode of expression.

Fig. 9 is the sequential chart of drive controlling of the piezo-activator of described execution mode.

Figure 10 is the curve chart of the power consumption that causes of the drive controlling of piezo-activator of the described execution mode of expression etc.

Figure 11 is the flow chart of drive controlling of the piezo-activator in the variation 1 of described the 1st execution mode of expression.

Figure 12 is the flow chart of drive controlling of the piezo-activator in the variation 2 of described the 1st execution mode of expression.

Figure 13 is the block diagram of structure of the piezoelectric actuator drive control device in the variation 4 of described the 1st execution mode of expression.

Figure 14 is the outside drawing of the clock and watch of the 2nd execution mode of the present invention.

Figure 15 is the block diagram of the structure of the piezoelectric actuator drive control device in the described execution mode of expression.

Figure 16 is the block diagram of the outside summary structure of the controller that has of the piezoelectric actuator drive control device of expression in the described execution mode.

The curve chart of the variation of the phase difference when Figure 17 is the frequency scanning of drive signal of the vibrating body of expression in the described execution mode, the rotating speed of rotor, current value.

Figure 18 is the major part enlarged drawing of the curve chart of Figure 17.

Figure 19 is the figure of the table information of storing in the storage part of the described execution mode of expression.

Figure 20 is the optimum phase difference obtaining step of piezoelectric actuator drive control device of the described execution mode of expression and the flow chart that the phase difference counter-rotating detects step.

Figure 21 is the flow chart of actuation step of the piezoelectric actuator drive control device of the described execution mode of expression.

Figure 22 is the flow chart of low-power consumption actuation step of the described driving control device of the described execution mode of expression.

Figure 23 is the figure of variation of drive characteristic of the piezo-activator of the described execution mode of expression.

Figure 24 is the curve chart of drive characteristic of the piezo-activator of the described execution mode of expression.

Figure 25 is the figure that compares with Figure 24, is illustrated in the curve chart of the drive characteristic when not implementing the driving frequency restriction in the piezo-activator of described execution mode.

Figure 26 is the flow chart of drive controlling of the piezo-activator in the variation 1 of described the 2nd execution mode of expression.

Figure 27 is the flow chart of drive controlling of the piezo-activator in the variation 3 of described the 2nd execution mode of expression.

Figure 28 is the block diagram of structure of the driving control device of expression the 3rd execution mode of the present invention.

Figure 29 is the flow chart of optimum phase difference obtaining step of the piezoelectric actuator drive control device of the described execution mode of expression.

The curve chart of the rotating speed (driving amount) of phase difference, rotor when Figure 30 is the frequency scanning of expression drive signal, the variation of current value.

Embodiment

[the 1st execution mode]

Below, with reference to description of drawings the 1st execution mode of the present invention.

In addition, in the later explanation of the 2nd execution mode, to the 1st execution mode of structure and following explanation identical give same-sign and omission or simplified illustration.

[1. general structure]

Fig. 1 is the vertical view of the electronic watch 1 that relates to of expression present embodiment.Electronic watch 1 is a wrist-watch, this wrist-watch also has the device displaying calendar date 90 that shows date from the window portion 3A that is located on the dial plate 3 except having the movement 2 as timing portion, the dial plate 3 as the clocking information display part that is used to show the common moment, hour hands 4, minute hand 5, second hand 6.

[the 2. structure of device displaying calendar date]

Fig. 2 is the vertical view of expression device displaying calendar date 90.Device displaying calendar date 90 is roughly by constituting with the lower part: piezo-activator 20; Driven the rotor 30 as driven member of rotation by this piezo-activator 20; The train of reduction gears of transmitting after the rotational delay with rotor 30 40; By means of the date gear 93 that rotates by the actuating force of train of reduction gears 40 transmission.Train of reduction gears 40 is by constituting with the lower part: with rotor 30 arranged coaxial, with the gear 41 of rotor 30 one rotation; Be engaged on the date rotation idler gear 94 on the gear 41; With date swing pinion 95.These piezo-activators 20, rotor 30, date rotation idler gear 94 and date swing pinion 95 are supported on the base plate 9D.

In addition, (dorsal part) is provided with below base plate 9D: the stepping motor (not shown) that the pulse signal that vibrates according to quartz vibrator moves; Be connected with stepping motor, drive the gear train of handling the needle (not shown) of hour hands 4, minute hand 5, second hand 6; And as battery 91 of power supply etc.Battery 91 provides electric power to each circuit of the driving control device 50 (Fig. 5) of stepping motor and piezo-activator 20, piezo-activator 20.

Date rotation idler gear 94 is made of large-diameter portion 941 and minor diameter part 942.Minor diameter part 942 is path cylindrical shapes that diameter is slightly less than large-diameter portion 941, is formed with the roughly notch 943 of square shape on its outer peripheral face.This minor diameter part 942 is fixed and is bonded on the large-diameter portion 941 and concentric with it.On large-diameter portion 941, meshing the gear 41 on the top of rotor 30.Therefore, the date rotation idler gear 94 that is made of large-diameter portion 941 and minor diameter part 942 rotation with the rotation interlock of rotor 30.

Be provided with leaf spring 944 on the side base plate 9D of date rotation idler gear 94, the base end part of this leaf spring 944 is fixed on the base plate 9D, and leading section is formed roughly V word shape by bending.The leading section of leaf spring 944 is set to the notch 943 that can come in and go out in date rotation idler gear 94.Dispose contact shoe 945 on the position near leaf spring 944, when the leading section of 94 rotations of date rotation idler gear, leaf spring 944 entered notch 943, this contact shoe 945 contacted with leaf spring 944.And leaf spring 944 is applied in the voltage of regulation, and when contacting with contact shoe 945, this voltage also imposes on contact shoe 945.Therefore,, the date travel condition can be detected, 93 1 days rotation amount of date gear can be detected by detecting the voltage of contact shoe 945.

In addition, the rotation amount of date gear 93 is not limited to use the parts of leaf spring 944 and contact shoe 945, also can use the parts etc. of exporting the pulse sequence number of regulation by the rotation status of detection rotor 30 and date rotation idler gear 94, specifically, can use various rotary encoders such as known reflective optical system, optical chopper, MR transducer etc.

Date gear 93 is shape in the form of a ring, and side face is formed with internal gear 931 within it.Date swing pinion 95 has five gears, and is meshed with the internal gear 931 of date gear 93.And, be provided with axle 951 at the center of date swing pinion 95, this 951 with moving about insertion be formed among the through hole 9C on the base plate 9D.Through hole 9C forms longlyer along the circumferencial direction of date gear 93.And date swing pinion 95 and axle 951 are pushed away to bullet to the upper right side of Fig. 2 by the leaf spring 952 that is fixed on the base plate 9D.Bullet by this leaf spring 953 pushes away effect, also can prevent shaking of date gear 93.

[the 3. structure of piezo-activator unit]

As shown in Figure 3, Figure 4, piezo-activator 20, rotor 30 and gear 41 are turned to piezo-activator unit 10 by the unit.

Piezo-activator unit 10 constitutes to have: be fixed on the supporting bracket 11 on the base plate etc. of electronic watch 1; Be fixed on the piezo-activator 20 on the supporting bracket 11; Rotation is installed in rotor 30 and the gear 41 on the supporting bracket 11 freely.

In addition, gear 41 constitutes its rotation and can detect by the rotation sensor 15 as test section that is configured in gear 41 tops.

Supporting bracket 11 forms porose 12 so that lightweight, and utilizes fixed part 13 such as screw to be fixed on the base plate etc.And, on supporting bracket 11, be fixed with the cushion block 14 that piezo-activator 20 has been installed.

[the 4. structure of piezo-activator]

Piezo-activator 20 has vibrating body 20A, and this vibrating body 20A is made of tabular stiffener 21 of essentially rectangular and the piezoelectric element 22 that is bonded on stiffener 21 two sides.

Length direction substantial middle at stiffener 21 is formed with to two side-prominent arms 23, and these each arms 23 utilize Screw 24 to be fixed on the described cushion block 14.In addition, the stiffener 21 with arm 23 utilizes conductive metal to constitute, and arm 23 also is used as the electrode that applies drive signal to piezoelectric element 22.

In the length direction one square end portion of stiffener 21, be and rotor 30 opposed ends specifically, be formed with along the outstanding projection 25 of the length direction of stiffener 21 the side butt of projection 25 and rotor 30.This projection 25 for the regulation power and the outer peripheral face butt of rotor 30, under the state that has been set with the relative position of rotor 30, being played the pushed section bullet arbitrarily by spring etc. pushes away, suitable frictional force acts between the side of projection 25 and rotor 30, and the vibration of vibrating body 20A effectively passes to rotor 30 thus.

In addition, in the present embodiment, be formed with groove 31 (Fig. 3), dispose projection 25 in these groove 31 parts at the outer peripheral face of rotor 30.When the situation lower piezoelectric actuator of dropping at similar electronic watch 1 20 has been applied in impact, can utilize these groove 31 channeling conducts that projection 25 is not broken away from from the bearing surface of rotor 30.

It is tabular that piezoelectric element 22 forms essentially rectangular, is bonded on the essentially rectangular shape part on stiffener 21 two sides.Two sides at piezoelectric element 22 is formed with electrode by plating, sputter, evaporation etc.

In addition, whole face is formed with an electrode on the one side of stiffener 21 sides of piezoelectric element 22, by stiffener 21 and the arm 23 that contacts with this electrode, is electrically connected (with reference to the N among Fig. 5) with driving control device 50 (Fig. 5).

And, on the face side one side of piezoelectric element 22, be formed with the electrode that is divided into 5 as shown in Figure 4.That is, the electrode of the face side of piezoelectric element 22 roughly is divided into three parts on the Width of piezoelectric element 22, utilizes its central electrode to form drive electrode 221.And the electrode of drive electrode 221 both sides roughly is divided into two parts at the length direction of piezoelectric element 22, forms paired respectively drive electrode 222 and drive electrode 223 on the diagonal angle of piezoelectric element.

These drive electrodes 221,222,223 respectively by lead etc. be connected with driving control device 50 (with reference to the P1 among Fig. 5～P3), and stiffener 21 (with reference to the N among Fig. 5) between be applied in voltage.In addition, the power supply of driving control device 50 is provided with following three kinds: the voltage between drive electrode 221 and the stiffener 21 applies uses power supply; Voltage between drive electrode 222 and the stiffener 21 applies uses power supply; Voltage between drive electrode 223 and the stiffener 21 applies uses power supply.

In this electronic watch 1, when changing on the date, driving control device 50 (Fig. 5) and piezo-activator 20 startings.And, providing single-phase drive signal by driving control device 50 to piezo-activator 20, rotor 30 is being driven and is rotating.

Herein, still be the date change of date timing according to the date change that is based on timing, to distinguish and use the drive electrode of being located on the piezoelectric element 22 222,223, rotor 30 is being driven at both direction and is rotating.

Promptly, if based on the change of date of timing, drive electrode 221 and drive electrode 222 become the object that voltage applies, because of the flexible extensional vibration that encourage of piezoelectric element 22 and the phase difference of flexural vibrations, the projection 25 of vibrating body 20A is drawn the track E (Fig. 4) of substantially elliptical shape of center line inclination of the length direction of relative piezoelectric element 22 according to vibrating body 20A.On the part of this track E, projection 25 is pushed rotor 30, and rotor 30 rotates along positive direction (direction of arrow among Fig. 4) thus.On the other hand, if the date of date timing change, drive electrode 223 replaces drive electrode 222 becomes the object that voltage applies, the length direction center line that drive electrode 222 and drive electrode 223 are in piezoelectric element 22 is the position relation that axle is the line symmetry, so when the direction of intersecting with respect to extensional vibration has applied voltage to drive electrode 222, the flexural vibrations of excitation line symmetry.Therefore, the projection 25 of vibrating body 20A forms the line symmetry when drive electrode 222 has been applied voltage and direction of rotation is reverse substantially elliptical shape track, and rotor 30 is being driven counter-rotating.

By this rotation of rotor 30, with rotor 30 be that the gear 41 of one also rotates, rotatablely moving of gear 41 passes to date rotation idler gear 94.And when the tooth of date swing pinion 95 was engaged on the notch 943 of date rotation idler gear 94, date gear 93 was advanced by date swing pinion 95, and the date that date gear 93 shows is changed.

In addition, the detection signal of the vibrational state of expression vibrating body 20A detects by the drive electrode 223 that is not applied to drive signal when rotor 30 is just changeing, and when rotor 30 counter-rotatings, detects by the drive electrode 222 that is not applied to drive signal.

And the detection of the rotating speed by 15 pairs of gears 41 of rotation sensor comes the rotating speed of detection rotor 30.

[the 5. structure of piezoelectric actuator drive control device]

Below, the structure of the driving control device 50 of piezo-activator 20 is described according to Fig. 5.

In Fig. 5, driving control device 50 constitutes to have: as the voltage-controlled oscillator (VCO) 51 of source driving signal; Pulse control circuit 52; Gate drivers 53; Power supply 54; Switching circuit 55; Band pass filter (BPF) 56; Signal amplifier (AMP) 57; Phase difference detection portion 60; Controller 65 as control part; And the revolution detector 71 of the rotating speed of detection rotor 30.

Voltage-controlled oscillator 51 is the oscillators that can change the frequency of the signal that will export according to the voltage that applies, produces the reference signal of the drive signal that is used to generate piezo-activator 20 with the benchmark pulsewidth of regulation.

But about the frequency (driving frequency) of drive signal, the resonance point of the extensional vibration of consideration vibrating body 20A and the resonance point of flexural vibrations wait to determine.

The driving frequency of Fig. 6 (A) expression vibrating body 20A and the relation of impedance, driving frequency and the amplitude of extensional vibration and the relationship of amplitude of flexural vibrations of Fig. 6 (B) expression vibrating body 20A.Shown in Fig. 6 (A), impedance phase is very little for driving frequency, and 2 amplitudes occurring is maximum resonance point, and the side that its medium frequency is lower is the resonance point of extensional vibration, and a higher side is the resonance point of flexural vibrations.

That is, when driving vibrating body 20A between the crooked syntony frequency f r2 of vertical resonance frequency fr1 of extensional vibration and flexural vibrations, can guarantee extensional vibration and flexural vibrations both sides' amplitude, piezo-activator 20 drives with high efficiency.In addition, by making vertical resonance frequency fr1 and crooked syntony frequency f r2 approaching mutually, can set the bigger driving frequency of amplitude of extensional vibration and flexural vibrations.

Return Fig. 5, pulse control circuit 52 is according to the command value of coming self-controller 65, with respect to the pulsewidth of benchmark pulsewidth restriction by the drive signal of voltage-controlled oscillator 51 generations, it constitutes has: Dead Time (dead time) generative circuit 521, its generation are used to control the switching timing of switching circuit 55 described later to suppress the Dead Time of perforation electric current; Forward counter-rotating circuit 522, the direction of rotation of its Switch Rotor 30, and export its command value; Pulse width control circuit 523, its output and the relevant command value of pulse restriction; Pulsewidth restricting circuits 524, it implements to comprise the pulse control of inserting Dead Time, the pulse duty factor of regulation drive signal to per 1 cycle.

Gate drivers 53 is the drive circuits that end according to the conducting from the drive signal control switch circuit 55 of pulse control circuit 52 output, has two the 1st gate drivers 53A, the 2nd gate drivers 53B in the present embodiment.

And,,, become the signal that reverses with the drive signal of input the 1st gate drivers 53A through inverter (NOT circuit) 58 from the drive signal of pulse control circuit 52 inputs the 2nd gate drivers 53B.

Power supply 54 is made of following power supply in the present embodiment: the 1st power supply 541 that uses when rotor 30 forward counter-rotatings, the 2nd power supply 542 that only uses when rotor 30 is rotated in the forward and the 3rd power supply 543 that uses during only in rotor 30 counter-rotatings, utilize these the 1st, the 2nd, the 3rd power supplys 541,542,543, apply the voltage of the potential difference between power vd D and the VSS or the supply voltage of the potential difference between power vd D and the GND to piezo-activator 20.

Switching circuit 55 is by constituting with the lower part: utilize P channel MOS-switch 551,552,555,557 of FET formation and the switch 553,554,556,558 that utilizes N-channel MOS-FET to constitute.These each switches 551～558 are controlled its conducting and are ended by imposed on the voltage of grid by the 1st gate drivers 53A, the 2nd gate drivers 53B control.

In addition, the 2nd gate drivers 53B connects forward counter-rotating circuit 522, when rotor 30 is rotated in the forward, and a driving switch 552,553 (P1 among Fig. 5) and switch 555,556 (P2).

Promptly, when rotor 30 is rotated in the forward, the 2nd gate drivers 53B of the 1st gate drivers 53A of driving switch 551,554 and driving switch 552,553 (P1) and switch 555,556 (P2), drive signal action with mutual counter-rotating, so the switch 551,552 of identical P channel MOS-FET is when side's switch 551 conductings, the opposing party's switch 552 ends.In addition, this switch 551,555 for identical P channel MOS-FET is also identical.

And same, the switch 553,554 of N-channel MOS-FET is when side's switch 553 conductings, and the opposing party's switch 554 is by (this switch 556,554 for N-channel MOS-FET is also identical).

And the switch 551,554 that is connected in series is when side's conducting, and the opposing party ends.Equally, switch 552,553 that is connected in series or switch 555,556 also are that the opposing party ends when side's conducting.

These switches 551～554 (perhaps switch 551,555,556,554) are bridge-type by the 1st gate drivers 53A, the relative piezoelectric element 22 of the 2nd gate drivers 53B and connect, utilization is positioned at the switching circuit that the pair of switches 551,553 (or switch 551,556) at the diagonal angle of bridge constitutes and utilizes another to the switching circuit that switch 552,554 (or switch 555,554) constitutes, and alternately being controlled conducting ends.Thus, the predetermined power voltage that applies by power supply 54 is converted into square-wave voltage alternately, imposes on piezo-activator 20 then.That is, utilize the 1st power supply 541 and the 2nd power supply 542 to apply alternating voltage to piezoelectric element 22 between drive electrode 221,222 and stiffener 21 (Fig. 3), rotor 30 is rotated in the forward.

On the other hand, when rotor 30 counter-rotatings, the 2nd gate drivers 53B driving switch 557,558 (P3) comes place of switches 555,556 (P2), switch 551,552,553,554 (or switch 551,557,558,554) piezoelectric element 22 relatively is the bridge-type connection, utilization is positioned at the switching circuit of switch 551,553 (and switch 551,558) formation and the switching circuit that utilizes switch 554,552 (or switch 554,557) to constitute, and alternately being controlled conducting ends.That is, utilize the 1st power supply 541 and the 3rd power supply 543 to apply alternating voltage to piezoelectric element 22 between drive electrode 221,223 and stiffener 21 (Fig. 3), rotor 30 carries out counter-rotating.

In addition, when the conducting of switching each switch 551～558 ends, if switch that is connected in series 551,554 and switch 552,553 (or switch 555,556 and switch 557,558) conducting simultaneously then causes perforation electric current to flow through.This perforation electric current is not used in the drive actions of piezo-activator 20, thus become the waste of power consumption, and become the reason of switch element scaling loss etc.Therefore, in pulse control circuit 52, after side's switch ends, after through the stipulated time (Dead Time), make the opposing party's switch conduction, prevent perforation electric current thus.

Band pass filter (unimodal filter) 56 vibrational states according to piezo-activator 20 for the detection signal that is detected, only make the detection signal of the frequency that comprises in the frequency range of regulation pass through, and make the signal attenuation of frequency in addition.

In addition, detection signal is rotated in the forward and counter-rotating according to rotor 30, and the either party detects (with reference to the P2 among Fig. 5, P3) in the drive electrode 222 by not being provided drive signal, the drive electrode 223.Herein, detection signal be by the current potential of arm 23 (N among Fig. 5) as reference signal, utilize the potential difference of drive electrode 222 relative these reference signals or drive electrode 223 relative datum signals potential difference, be that the differential wave of drive electrode 222,223 relative arms 23 detects.

Detection signal by band pass filter 56 is amplified by signal amplifier 57.

Phase difference detection portion 60 constitute have phase controller 61, phase shifter 62, phase comparator 63 and low pass filter (LPF) 64.

61 every two cycles through detection signal of phase controller are just exported control signals to phase shifter 62, and phase shifter 62 makes the predefined optimum phase difference of the phase shifts of detection signal thereupon.

Phase comparator 63 is relatively from the phase place of the detection signal of phase shifter 62 output with from the phase place of the drive signal of voltage-controlled oscillator 51 outputs, and exports its phase difference.Herein, as previously described, phase shifter 62 makes the phase shifts optimum phase difference of detection signal, and the output of phase comparator 63 approaching more zero is just more near optimum phase difference.

Low pass filter 64 is that the signal of the following frequency of assigned frequency is passed through, and makes the filter of the signal attenuation of the above frequency of assigned frequency, plays a role as integrating circuit.

According to above phase difference detection portion 60, between the phase place of the detection signal after moving by phase shifter 62 and the phase place of drive signal poor, promptly with the deviation (size) of optimum phase difference, export to controller 65 by low pass filter 64.

Controller 65 is to voltage-controlled oscillator 51 output voltage signals, and simultaneously to pulse control circuit 52 output order values, with the deviation of elimination with the optimum phase difference of being imported, it constitutes has storage part 651.

In storage part 651, store the setting rotating speed of expression driving rotor 30 needed MIN torques (actuating force).

This setting rotating speed is determined according to the drive characteristic of piezo-activator 20.

The rotating speed of the rotor 30 when Fig. 7 represents the pulsewidth (Duty) of scanning drive signal.In the present embodiment, according to the relation of the inertia of rotor 30 etc., the minimum speed rotor 30 during with minimum actuating force rotation is considered as about 600rpm, in storage part 651 the storage minimum speed promptly " 600rpm " as the setting rotating speed.

In addition, the benchmark pulsewidth of the drive signal that voltage-controlled oscillator 51 produces is set to the maximum pulse width (Duty100%) that realizes maximum driving force in the drive characteristic of piezo-activator 20.Maximum driving force waits to determine according to the pressurized conditions of inertia, rotor 30 and the vibrating body 20A of piezo-activator 20 desired outputs, rotor 30.

Revolution detector 71 for example constitutes and comprises speed probe 15, and it detects and rotor 30 is the rotating speed of the gear 41 (Fig. 3) of one.

[the 6. drive controlling of piezo-activator]

Below, with reference to flow chart shown in Figure 8 and sequential chart shown in Figure 9, the effect of the piezo-activator 20 that adopts driving control device 50 is described.

The controller 65 (Fig. 5) of driving control device 50 according to shown in Figure 8, carried out initial value and is set step S10 and drive controlling circulation S20 after starting.

At first, set step S10 at initial value, the pulsewidth T that slave controller 65 is exported to the drive signal of pulse control circuit 52 is initialized as " 0% ", and utilizes the setting rotating speed of reading from storage part 651 " 600rpm ", the variable Z0 initialization that will use in controller 65.

Drive controlling circulation S20 constitutes and comprises that pulsewidth is set step S21 and according to the pulse width control step S22 of the pulsewidth of the speed setting drive signal of rotor 30, continue to carry out this circulation, till the signal input controller 65 that the expression driving finishes (step S100).

Pulsewidth is set the pulsewidth T that step S21 setting controller 65 is exported to the drive signal of pulse control circuit 52.After piezo-activator 20 starting just, T is initial value " 0% ", and the pulsewidth that offers the drive signal of piezo-activator 20 by pulse control circuit 52 becomes " 0% ".

And, after in next step S100, confirming to continue to drive, change pulse width control step S22 over to.Pulse width control step S22 comprises that the rotating speed of the rotating speed of detection rotor 30 detects step S221 and detects to determine the pulsewidth set-up procedure S222 of the pulsewidth of drive signal according to the rotating speed of the rotor 30 among this step S221.

Detect among the step S221 at rotating speed, the rotating speed that obtains by revolution detector 71 (Fig. 5) is saved as variable Z1.

And, in the pulsewidth set-up procedure S222 of back, relatively detect the rotating speed (Z1) of the rotor 30 that obtains among the step S221 and set the setting rotating speed of setting among the step S10 (Z0) at initial value at rotating speed, when detecting rotating speed Z1 greater than setting rotating speed Z0, change step S222A over to, make pulsewidth T reduce Δ T (being 0.1% in the present embodiment).On the other hand, when setting rotating speed Z0, change step S222B over to, make pulsewidth T increase Δ T (being 0.1% in the present embodiment) at rotating speed Z1.

Set step S10 and drive controlling circulation 20 according to the initial value of above explanation, can control the pulsewidth of the drive signal that offers piezo-activator 20.

The signal waveform at each positions such as A～H in Fig. 9 difference presentation graphs 5.Among Fig. 9, A represents that the frequency of this reference pulse signal A and benchmark pulsewidth P are roughly certain from the reference pulse signal of voltage-controlled oscillator (VCO) 51 outputs.Among Fig. 9, B represents to be used to represent the output of revolution detector 71 of the rotation of rotor 30.

And C, D, E, F represent the drive signal that opens and closes by the 1st, the 2nd gate drivers 53A, 53B in each switch 551～554.

Reference pulse signal A is transfused to pulse control circuit 52, in this pulse control circuit 52, utilization is with respect to benchmark pulsewidth P and confined value generates the pulsewidth T of drive signal, and in each switch 551～554, the waveform of representing respectively according to the C～F among Fig. 9 carries out conducting by control.Promptly, it is roughly consistent to be configured in the timing that the conducting separately of the switch (among Fig. 5 for C and E (E2, E3 are also identical with E) or F and D (D2, D3 are also identical with D)) at the place, diagonal angle of bridge ends, end by the conducting of alternately controlling these switches, provide alternate voltages 1 with pulsewidth T to piezo-activator 20, vibrating body 20A vibrates according to the flexible of piezoelectric element 22.

Herein, the pulsewidth of drive signal C～F in aforesaid pulse width control step S22 (Fig. 8), makes it from increasing pulsewidth T (step S222B) as the interval X of the braking of non-driven state (on-position) after starting, increase gradually thus, rotor 30 begins rotation thereupon.And after the process stipulated time, the driving condition of piezo-activator 20 becomes stable state Y, the rotating speed of rotor 30 and the pulsewidth T of drive signal convergence.The definite pulse duty factor of pulsewidth (Hi part) of drive signal according to this moment is about 10%, this pulsewidth T as shown in Figure 7, the minimum speed (600rpm) corresponding to rotor 30 is equivalent to minimum pulse width.That is needed MIN pull up torque drove during, rotor 30 drove with this rotation.

The graphical representation of Figure 10 is by the driveability of the piezo-activator 20 of driving control device 50 such drive controlling.In this Figure 10, show the rotating speed of rotor 30 and the power consumption of piezo-activator 20 and driving control device 50 and how to change according to the pulsewidth T of drive signal respectively.Specifically, show situation when not limiting the pulse duty factor 100% of pulsewidth T of drive signal, the situation when being kept at that setting rotating speed in the storage part 651 is made as " 1500rpm " and having carried out the restriction of pulsewidth T and respectively setting the situation (present embodiment) that rotating speed is made as " 600rpm " and has carried out the restriction of pulsewidth T according to step shown in Figure 8 with respect to benchmark pulsewidth P.In addition, when the setting rotating speed was 1500rpm, the pulse duty factor of drive signal was about 30%, and as previously described, the pulse duty factor of drive signal is about 10% when the setting rotating speed is 600rpm.

, when the restriction of the pulsewidth T that has carried out drive signal, compare when not limiting pulsewidth, power consumption obviously reduces as can be known herein.

[the 7. effect of present embodiment]

Can obtain following effect according to present embodiment.

(1) in the driving control device 50 of the piezo-activator 20 that drives device displaying calendar date 90, with respect to benchmark pulsewidth P, the pulsewidth T of drive signal is restricted to the degree that can drive rotor 30.As a result, can reduce the pulse duty factor of drive signal in rectangular wave drive.Therefore, even the output of the regulation of piezo-activator 20 is set to higher output, make that be (pulse duty factor 100%) needed torque in 100% o'clock considerably beyond the pulsewidth T of drive signal with respect to benchmark pulsewidth P, also can be by limiting the pulsewidth T of this drive signal, output is reduced to can the actual degree that drives rotor 30.Therefore, compare during with pulse restriction that does not have drive signal and pulse duty factor 100%, can especially realize low-power consumption.

(2) and, minimum speed when setting drives rotor 30 with the pull up torque that can drive rotor 30, carry out drive controlling so that the rotating speed of rotor 30 remains near this minimum speed, so when driving rotor 30, the output of piezo-activator 20 can be reduced to the limit.That is, the amount of power consumption of piezo-activator 20 and driving control device 50 can be suppressed to Min..

(3) in addition, driving control device 50 has revolution detector 71, in drive controlling circulation S20, utilizes the rotating speed of revolution detector 71 detection rotors 30, according to the pulsewidth of this speed setting drive signal.As a result,, also can reliably obtain desired actuating force, can stably drive rotor 30 even during the changes such as pressurized conditions of piezo-activator 20 wearing and tearing, piezo-activator 20 and rotor.

(4), can realize that low-power consumption drives by assembling driving control device 50 on electronic watch 1.Can prolong the life-span of battery 91 thus.Therefore, the frequency of battery altering reduces, and can improve maintenance characteristics.

Herein, the variation to the 1st execution mode of above explanation describes.

[variation 1 of the 1st execution mode]

In aforementioned embodiments, set among the step S10 at initial value, the pulsewidth T that slave controller 65 is exported to the drive signal of pulse control circuit 52 is initialized as " 0% ", but the initial value of pulsewidth T is not limited thereto, and can set arbitrarily.For example shown in Figure 11, also can utilize as " 10% " of suitable pulsewidth etc. pulsewidth T initialization, in drive controlling circulation S20, adjust the pulsewidth of drive signal, till the setting rotating speed according to rotor 30 becomes stable state.Like this, the pulsewidth 10% of drive signal is corresponding to the minimum speed 600rpm (Fig. 7) of rotor 30, so rotor 30 can be in stable state as early as possible, shortens the starting time of piezo-activator 20.That is, can accomplish low-power consumption fully, and needn't sacrifice priming speed.In addition, the initial value of the pulsewidth of drive signal is not limited to suitable pulsewidth " 10% ", for example also can " 5% " etc. less than the pulsewidth of suitable pulsewidth as initial value, improve pulse duty factor gradually according to the rotating speed that is detected.

[variation 2 of the 1st execution mode]

In addition, in the variation 1 of aforementioned the 1st execution mode, also can form following structure, in memory cell 651, preserve suitable pulsewidth (for example 10%), when after starting, being in stable state, suitable pulsewidth is kept in the storage part 651 again.That is, suitable pulsewidth is updated when each starting, because the pulsewidth when the driving rotor 30 of last time starting is in stable state becomes suitable pulsewidth, so can optimize actuating force and power consumption.

Perhaps, also can not utilize the pulsewidth when last time starting, and the pulsewidth of the drive signal of each the self-driven rotor 30 when repeatedly starting when being in stable state is kept in the storage part 651 as suitable pulsewidth.By obtaining repeatedly average like this, can optimize suitable pulsewidth, further optimize actuating force and power consumption.

[variation 3 of the 1st execution mode]

And, as shown in figure 12, also consider when drive controlling begins, to be provided with initialization step S00, the pulsewidth of scanning drive signal in this initialization step S00 is obtained the minimum speed that is used to realize to drive the minimal torque of rotor 30.During this situation, can implement drive controlling, so can obtain the needed torque of rotor 30 rotations reliably according to the minimum speed of actual measurement in initialization step S00.

[variation 4 of the 1st execution mode]

In addition, in aforementioned embodiments, the rotating speed of detection rotor 30 carries out drive controlling, but also can replace the rotating speed of rotor 30, and carries out drive controlling according to the current value of piezo-activator 20 in the comparison of rotating speed that is detected and minimum speed etc.During this situation, as shown in figure 13, driving control device 50A has the current detector 75 that detects the electric current that flows through piezo-activator 20, preserves the minimal minimum current value that can drive rotor 30 in the storage part 651 of controller 65.And, in drive controlling circulation S20, in the comparison of this minimum current value and the current value that detects by current detector 75, implement drive controlling.Thus, can obtain the effect roughly the same with aforementioned embodiments.

[variation 5 of the 1st execution mode]

In aforementioned embodiments, the setting that is illustrated in the actuating force of the regulation of using in the drive controlling is minimum speed " 600rpm ", but be not limited thereto, for example also can carry out drive controlling to rotating speed " 1000rpm " as setting (the setting rotating speed in the aforementioned embodiments).At this moment, the pulse duty factor of drive signal is about 25%, and rotor 30 is rotated near 1000rpm.

In a word, in the present invention, as long as with respect to the benchmark pulsewidth, the pulsewidth of drive signal is restricted to the degree of actuating force that realization can drive the regulation of driven member gets final product.

[the 2nd execution mode]

Below, with reference to Figure 14～Figure 25 the 2nd execution mode of the present invention is described.In the present embodiment, the piezo-activator 20 that hypothesis driven control is identical with the 1st execution mode, and the piezoelectric actuator drive control device of present embodiment and method comprise the piezoelectric actuator drive control device and the method for aforementioned the 1st execution mode.But, in the present embodiment,, realize the stabilized driving under the phase difference FEEDBACK CONTROL by implementing the distinctive step of present embodiment.

[structure of 2-1. electronic watch]

Figure 14 is the vertical view of the electronic watch 1A that relates to of expression present embodiment.Electronic watch 1A is the wrist-watch as time set, this wrist-watch also has the pointer 7A that clocks the second of representing the time of clocking, divides the pointer 7B that clocks except having the movement 2 as timing portion, the dial plate 3 as the clocking information display part that is used to show the common moment, hour hands 4, minute hand 5, second hand 6.On the watchcase of electronic watch 1A, be provided with table 8, be provided with action button 9A, the 9B that clocks to 8 across table.

In the present embodiment, the driving mechanism as driving the pointer 7A that clocks second uses at the piezo-activator unit 10 shown in the 1st execution mode (Fig. 2, Fig. 3).

[structure of 2-2. piezoelectric actuator drive control device]

Figure 15 represents the structure of the piezoelectric actuator drive control device 50A of present embodiment.

Figure 16 is the summary structure chart of controller 265, and controller 265 constitutes and comprises following each component part: FREQUENCY CONTROL portion 652, and it makes the frequency of drive signal follow the phase difference that feeds back by phase difference detection portion 60; Optimum phase difference acquisition unit 653, it obtains the optimum phase difference that is used to realize the driving condition stipulated; Frequency control part 654, what it made optimum phase difference obtains the frequency regularization; Phase difference counter-rotating test section 655, it is when the turntable driving frequency, and whether the phase difference of the phase place of detection drive signal and the phase place of detection signal can repeatedly obtain the value of target phase difference; Low powder pulsed control part (control part) 656, its command value that will limit the pulsewidth of drive signal is exported to pulse control circuit 52; The clamp portion 657 of restriction driving frequency; And storage part 658.Herein, initial setting section constitutes and has optimum phase difference acquisition unit 653 and phase difference counter-rotating test section 655.

FREQUENCY CONTROL portion 652 in the controller 265 has the function of following the unit of the phase difference that feeds back by phase difference detection portion 60 as the frequency that makes drive signal, to voltage-controlled oscillator 51 output voltage signals, with the deviation of elimination with the target phase difference of being imported.

Optimum phase difference acquisition unit 653 is carried out obtaining of optimum phase difference by frequency control part 654 with the regulation frequency, and the Continuous Drive time that this frequency rises when starting by the operation of action button 9A (Fig. 1) according to piezo-activator 20 is determined.Frequency in the present embodiment is 1 hour Continuous Drive time, and this time is stored in the storage part 658.

In storage part 658,, also storing the table information TBL (Figure 19) of driving frequency and expression drive rotor 30 needed torques (actuating force) with maximal efficiency roughly setting rotating speed " 1500rpm " respectively except that the Continuous Drive of above-mentioned frequency control part 654 references the time.

Among the table information TBL (Figure 19) in being stored in storage part 658, also store under the situation that when scanning the frequency of the drive signal that offers vibrating body 20A in advance, reaches target phase difference once more the clamp frequency relevant with the counter-rotating of this phase difference.

Phase difference, the rotating speed of rotor 30 and the curve chart that flows through the current value of piezo-activator 20 of vibrating body 20A when Figure 17 is the frequency of expression scanning drive signal, Figure 18 is the major part enlarged drawing of Figure 17.In addition, the value of this curve chart tilts with increase and decrease, and the individual difference because of vibrating body 20A is different sometimes.

The phase difference of drive signal and detection signal is the index of the vibration characteristics of vibrating body 20A, in the present embodiment, the phase difference that the rotating speed of rotor 30 is roughly maximum optimal drive state (driving condition of regulation) G is made as target phase difference θ (optimum phase difference in the present embodiment, about 100 °).When phase difference is this target phase difference θ, can be by the resonance of the extensional vibration of vibrating body 20A and the resonance of flexural vibrations, with maximal efficiency drive pressure electric actuator 20.

Be set with the stable driving scope U1 of vibration characteristics in driving control device 50, this driving scope U1 comprises optimal drive state G when carrying out the FEEDBACK CONTROL of phase difference, and the increase and decrease inclination of phase difference is a direction when the turntable driving frequency.Drive among scope U1 at this, when driving frequency was changed to augment direction, phase difference was rendered as minimizing trend, based on the driving frequency of the size of the relative target phase difference θ of phase difference to follow direction nonreversible.

Herein, in vibrating body 20A, owing to the applying error of piezoelectric element 22 and stiffener 21, based on the phase place of the extensional vibration that provides a drive signal to drive to vibrating body 20A and the reasons such as phase coincidence of flexural vibrations, example like that as shown in figure 17, can occur from lower frequency side when the augment direction turntable driving frequency, in the scope of driving U1, after reducing from target phase difference θ sometimes, phase difference increases and reaches once more the situation (rollback point Pt1) of target phase difference θ again.On this rollback point Pt1, phase difference increases, and it is opposite with the inclination (reducing) of the phase difference of optimal drive state G, return contact Pt2 tilting from the increase and decrease of this rollback point Pt1 before reach target phase difference θ once more and revert to counter-rotating is considered as the unsettled phase difference counter-rotating of phase difference FEEDBACK CONTROL scope Z.

Both sides at this phase difference counter-rotating scope Z, as shown in figure 18, be respectively equipped with apart from the phase difference reversal frequency F1 of rollback point Pt1 and be+wide phase difference recovery scope the R2 of 0.5kHz for the wide reversible scope R1 of phase difference of-0.5kHz with apart from the recovery frequency F3 of phase retrieval point Pt2.Promptly, the boundary value of the reversible scope R1 of phase difference is phase difference reversal frequency F1 and deducts clamp frequency F2 behind the 0.5kHz from this phase difference reversal frequency F1 that the boundary value that phase difference restores scope R2 is clamp frequency F4 when restoring frequency F3 and the recovery after this recovery frequency F3 adds 0.5kHz.

The frequency that the reversible scope R1 of phase difference of clamp frequency F4 and phase difference restore scope R2 when comprising these phase difference reversal frequencies F1, clamp frequency F2, recovery frequency F3 and recovery is stored in the storage part 658 with enumerating.

Figure 19 represents to be stored in the data content in the storage part 658.Storage part 658 is stored as table information TBL to the frequency of reversible scope R1 of phase difference and phase difference recovery scope R2.

[drive controlling of 2-3. piezo-activator]

Below, with reference to Figure 20～flow chart shown in Figure 22, the drive controlling of the piezo-activator 20 that adopts driving control device 50A is described.

The controller 265 of driving control device 50A is carried out optimum phase difference obtaining step P1 shown in Figure 20 respectively, the phase difference counter-rotating detects step P4 and actuation step P5 shown in Figure 21.

In addition, the initial setting step constitutes and comprises that optimum phase difference obtaining step P1 and phase difference counter-rotating detect step P4.

[effect of 2-3-1. frequency control part]

The timer function of controller 265 usage frequency control parts 654, elapsed time Tn, Continuous Drive time (step Sn11) by affirmation shown in Figure 20 during, implement optimum phase difference obtaining step P1 and the phase difference counter-rotating detects step P4 with the regulation frequency from piezo-activator 20 starting.Promptly, when confirming the Continuous Drive time (step Sn11), when the elapsed time Tn from piezo-activator 20 starting the time reaches Continuous Drive time N the storage part 658 that is stored in controller 265 (being), implement optimum phase difference obtaining step P1, and (deny) to change actuation step P5 shown in Figure 21 over to when not reaching.

In addition, elapsed time Tn is initialized to " 0 " when piezo-activator 20 startings.

[2-3-2. optimum phase difference obtaining step]

In optimum phase difference obtaining step P1, utilize the optimum phase difference acquisition unit 653 of controller 265, check the desired driving condition (in the present embodiment for driving the roughly maximum state of efficient (rotating speed of rotor 30)) of the piezo-activator 20 when driving rotor 30.

Specifically, will be low frequency (being 230kHz in the present embodiment) at first, and set the initial value (step Sn21) of the pulsewidth (Duty) of drive signal by the frequency setting of the drive signal of voltage-controlled oscillator 51 vibration.In addition, this Duty initial value for example is set at about 50%～95%.And, as the state of electric current restriction 0, according to the rotating speed from rotation sensor 15 (Fig. 2) input, the rotary speed of detection rotor 30 (step Sn22).In the detection of this rotary speed, use two (Zn0, Zn1) to keep the variable of rotating speed, when detecting rotary speed, with this rotating speed substitution Zn0, and relatively Zn0 and Zn1, at Zn0 during greater than Zn1, with Zn0 substitution Zn1.Thus, the rotating speed relevant with tentative maximum rotative speed in the process of turntable driving frequency is by substitution Zn1 and renewal successively.

Then, compare Zn0 and Zn1 (step Sn23), identical or during less than Zn1 (denying) at Zn0 (rotating speed when this time detecting) and Zn1 (remaining the value of the rotating speed relevant) with tentative maximum rotative speed, owing to do not detect the peak value of rotary speed as yet, so improve driving frequency (step Sn24) with the regulation amplitude, proceed scanning.In the present embodiment, the increase amplitude of the driving frequency during scanning is 0.5kHz, and driving frequency is scanned 280kHz from 230kHz in one direction.In addition, when this driving frequency scanning, also can be reduced to low frequency from high frequency.

On the other hand, when Zn0 is less than Zn1 in step Sn23 (being), can be judged as rotary speed and have surpassed peak value, so according to the data when last time detecting, the Zn1 that preserves for the time being is defined as representing the rotating speed of maximum rotative speed (maximum drive frequency) changing next step Sn25 over to.

In step Sn25, being fixed on rotating speed becomes under the frequency f d of Zn1, under this state, utilizes phase comparator 63 to measure phase difference (step Sn26).The phase difference of herein measuring is defined as optimum phase difference, is stored in the storage part 658 of controller 265 (step Sn27).According to the optimum phase difference of storing herein, carry out next phase difference counter-rotating and detect step P4.

Detect among the step P4 in phase difference counter-rotating, judge when turntable driving frequency, whether to produce the phenomenon (step Sn41, Sn42) that reaches optimum phase difference (with reference to the θ among Figure 17, Figure 18) and phase place extent evaluation counter-rotating once more.Phase shifter 62 is set optimum phase difference (θ) herein.

In these steps Sn41, Sn42, specifically, utilize the phase difference counter-rotating test section 655 of controller 265, scanning is by the frequency of the drive signal of voltage-controlled oscillator 51 vibrations from 230kHz to 280kHz in one direction for one side, and one side is implemented the phase difference feedback processing by phase difference detection portion 60.And, according to Figure 17 example like that, when producing the reversal development of phase difference, the result of determination of the clamp portion 657 that this phase difference counter-rotating relates to is a "Yes", generate table information TBL (Figure 19) (step Sn43), TBL is stored in (step Sn44) in the storage part 658 this table information.

On the other hand, when not producing the reversal development of phase difference, the result of determination of phase difference counter-rotating is a "No", in the present embodiment, and the data of the table information TBL in the deletion storage part 658.

After above optimum phase difference obtaining step P1 and phase difference counter-rotating detection step P4 end, elapsed time Tn is reset to " 0 " (step Sn28), change actuation step P5 over to.

[2-3-3. actuation step]

In actuation step P5 shown in Figure 21, at first, utilize 265 pairs of phase shifters 62 of controller to be set in the optimum phase difference (Figure 27) that is stored among the aforementioned optimum phase difference obtaining step P1 in the storage part 658, and set the initial value (step Sn31) of the pulsewidth (Duty) of drive signal.In addition, this Duty initial value for example is set at about 50%～95%.

And, begin turntable driving frequency (step Sn32) from 230kHz, implement the phase difference FEEDBACK CONTROL by phase difference detection portion 60 and FREQUENCY CONTROL portion 652 (Figure 16).Specifically, with increase amplitude turntable driving frequency (step Sn34) as hereinbefore, be " 0 " up to phase difference from phase comparator 63 outputs, that is, and phase difference and the optimum phase difference consistent (step Sn33) that phase shifter 62 is set.

Like this, phase difference and (step Sn33 is a "Yes") after optimum phase difference is consistent, carry out the phase difference FEEDBACK CONTROL equally by phase difference detection portion 60 later on, make the frequency of drive signal follow the phase difference feedback step Sn35 of the phase difference of detection signal and drive signal.That is, utilize the voltage signal of FREQUENCY CONTROL portion 652 control input voltage control generators 51, make from phase comparator 63 and be output as zero, promptly phase difference becomes optimum phase difference.Herein, at the formation voltage signal and when exporting to voltage-controlled oscillator 51, the driving frequency that the voltage signal that judgement will generate is represented whether with the frequency consistent (step Sn522) of table information TBL (Figure 19).

The driving frequency of representing at the voltage signal that will generate, generates this voltage signal and exports to voltage-controlled oscillator 51 when inconsistent (deny) with the frequency of table information TBL, the result, and the frequency of the drive signal that voltage-controlled oscillator 51 vibrates is changed.

That is, when driving condition is Q1 (Figure 18), with respect to optimum phase difference (with reference to the θ among Figure 18), have the bigger overgauge D1 of phase difference (Figure 18), during this situation, driving frequency is changed to the increase direction, so that phase difference reduces.And, when driving condition is Q2,, there is the less minus deviation D2 of phase difference (Figure 18) with respect to target phase difference (θ), during this situation, driving frequency is changed to reduces direction, so that phase difference increases.

As long as should be inconsistent with the frequency of table information TBL, just repeat these steps Sn35 and Sn522 by the driving frequency that the voltage signal that controller 265 generates is represented.

In addition, when in the phase difference counter-rotating detection step P4 that in advance implements, not producing the counter-rotating of phase difference, in the present embodiment, do not carry out driving frequency that voltage signal represents whether with table information TBL in the consistent judgement (Sn522) of frequency, whenever the input detection signal time, the voltage signal that controller 265 generates is controlled (Sn35).

On the other hand, when the frequency of the driving frequency that should be represented by the voltage signal that controller 265 generates and table information TBL (Figure 19) is consistent ("Yes"), the generation of this voltage signal of strangulation, export processing (Sn523).

Thereupon, the frequency of the drive signal of voltage-controlled oscillator 51 vibrations is held, driving frequency is limited following of phase difference, so driving frequency reaches phase difference reversal frequency F1 through clamp frequency F2, can prevent to follow the direction counter-rotating based on the driving frequency of phase difference.Thus, can prevent under the state that the evaluation of phase difference has been reversed, to carry out FEEDBACK CONTROL reliably.

, suppose that driving frequency is not limited following of phase difference herein, then the driving condition of piezo-activator 20 might change driving condition Q4 over to through the driving condition Q3 of the reversible scope R1 of phase difference.Under this driving condition Q4, make it near optimal drive state G although need to reduce driving frequency, because phase difference is with respect to target phase difference θ big (+), so driving frequency is changed to the increase direction, so that phase difference reduces.

Promptly, before and after rollback point Pt1, because based on following the direction counter-rotating with respect to the driving frequency of the phase place extent of target phase difference θ, so driving frequency is changed to the opposite direction of proper orientation, driving condition enters driving condition Q5 from driving condition Q4, changes the direction that departs from optimal drive state G over to.Between this driving condition Q4 and Q5, the increase and decrease tilt variation of phase difference, later on before and after the target phase difference θ return contact Pt2 identical with the phase difference level, feed back by phase difference, driving frequency is changed, even the driving condition of piezo-activator 20 is away from optimal drive state G, also almost can not return near the state of optimal drive state G.

In order to prevent this situation, according to restriction driving frequency noted earlier following to phase difference.

Herein, with the big amplitude (0.5kHz) of amplitude of swinging with variations in temperature because of following of relative phase difference than driving frequency, setting departs from the clamp frequency F2 of phase difference reversal frequency F1, according to noted earlier, the restriction driving frequency makes it can not reach clamp frequency F2, can prevent to carry out under the state that the evaluation of phase difference has been reversed FEEDBACK CONTROL thus reliably.

In addition, at clamp (Sn523) afterwards, return the processing that step Sn521 proceeds corresponding next detection signal, when in step Sn522, being "No", make the frequency of drive signal follow phase difference.

By above step, make driving frequency fixing and follow phase difference, the variation that vibration characteristics that can corresponding vibrating body 20A takes place because of variations in temperature etc., and produce at phase difference under the situation of reversal development, also can be not in the direction controlling and driving frequency of mistake, stably the drive controlling piezo-activator 20.

, among the table information TBL (Figure 19) in storage part 658, except that the reversible scope R1 of phase difference, also store the frequency data that phase difference restores scope R2 herein, this phase difference restores the value of scope R2 to be used in the following cases.

For example, be referenced at clamp frequency F2, when the output of the voltage signal of controller 265 is clamped down on, compare return contact Pt2, the situation etc. that drives the driving scope J (Figure 17) move to high frequency side at needs down, preferably the frequency with reference to this phase difference recovery scope R2 limits driving frequency, so that driving condition can be stablized.That is, driving frequency is followed in the processing of phase difference, before the change driving frequency, whether the driving frequency that judgement will be changed is consistent with the value of phase difference recovery scope R2, when unanimity, processing clamped down on, to keep driving frequency.

If carry out this drive controlling, then under the state except the unsettled phase difference counter-rotating of the drive controlling scope Z, can stably carry out drive controlling.

And the optimal drive state is compared return contact Pt2 and is positioned at high frequency side, under need be with the situation that drives scope J drive pressure electric actuator 20, too as long as restore the processing that scope R2 limits driving frequency with reference to this phase difference.

In addition, phase difference during driving frequency scanning as shown in figure 17, increase, reduce repeating, when the increase and decrease of phase difference is tilted not necessarily, also consider the situation that the evaluation reversal development with respect to the phase difference of the target phase difference that sets (for example θ ' among Figure 17) produces in many places.

In this case, can study the driving frequency that these counter-rotating reversible scopes of phase difference at positions and phase difference are restored scope is appended among the table information TBL (Figure 19) and carries out drive controlling.

Like this, in the gamut except the scope of phase difference counter-rotating, that the 230kHz～280kHz of driving frequency is scanned, can utilize driving control device 50 drive controlling piezo-activators 20.

In addition, behind clamp (Sn523), return step Sn35, proceed the processing of corresponding next detection signal, when in step S522, being "No", make the frequency of drive signal follow phase difference.

And,, the driving time timing variable of representing the elapsed time Tn of controller 265 is increased by 1 (step Sn351) when carrying out a series of processing of phase difference feedback step Sn35, Sn522, Sn523.

In the step Sn39 of back, change low-power consumption actuation step P6 shown in Figure 22 over to.This low-power consumption actuation step P6 is set in the circulation of phase difference FEEDBACK CONTROL of actuation step P5 (Figure 21) (Sn35, Sn522, Sn523, Sn351, Sn36, Sn37, Sn38), and the processing of carrying out at low-power consumption actuation step P6 is corresponding to the processing shown in Figure 8 of the 1st execution mode.And each processing of low-power consumption actuation step P6 is undertaken by low powder pulsed control part 656 (Figure 16).

In this low-power consumption actuation step P6, at first judge the initialization (S61) of the needed driving parameters of processing whether need to carry out low-power consumption actuation step P6, (be) when needed, in step S10, the pulsewidth T that slave controller 265 is exported to the drive signal of pulse control circuit 52 is initialized as " 0% ", and the variable Z0 that will use in controller 265 is initialized as the setting rotating speed of reading " 1500rpm " from storage part 658.In addition, when being "Yes" in this step S61, usually (beginning among Figure 20) becomes low-power consumption actuation step P6 and begins time of controlling for the first time afterwards during piezo-activator 20 startings.

After step S61,, implement similarly with the flow process among Fig. 8 that pulsewidth is set step S21 and according to the pulse width control step S22 of the pulsewidth of the speed setting drive signal of rotor 30 according to initialized driving parameters.

By this low-power consumption actuation step P6, control offers the pulsewidth of the drive signal of piezo-activator 20, the result, and the signal waveform at each position of A～H of driving control device 50A is identical with Fig. 9 of front.

That is, after starting, in aforesaid pulse width control step S22 (Figure 22), make the pulsewidth of drive signal C～F increase pulsewidth T (step S222B) from the interval X of the braking of non-driven state (on-position), increase gradually thus, rotor 30 begins rotation thereupon.And after the process stipulated time, the driving condition of piezo-activator 20 becomes stable state Y, the rotating speed of rotor 30 and the pulsewidth T of drive signal convergence.The definite pulse duty factor of pulsewidth (Hi part) of drive signal according to this moment is about 30%, and this pulsewidth T such as front shown in Figure 7 is corresponding to the rotating speed (1500rpm) of rotor 30.

On the other hand, have low-power consumption actuation step P6 and be driven the driveability of the piezo-activator 20 of control, the curve chart shown in Figure 10 with the front is identical, when the restriction of the pulsewidth T that carries out drive signal as present embodiment, compare when not limiting pulsewidth, can reduce power consumption.

Each of low-power consumption actuation step P6 more than finishing finishes the control of low powder pulsed control part 656 after handling, and turns back to the step Sn36 of the actuation step P5 among Figure 21.

Continue to carry out the phase difference FEEDBACK CONTROL among the actuation step P5, drive the signal that finishes up to expression and be transfused to controller 265 (step Sn36), perhaps the clock second signal of switching of direction of rotation of pointer 7A of expression is transfused to controller 265 (step Sn38).

Herein, when carrying out the drive controlling of piezo-activator 20, the phase difference of drive signal and detection signal as index (optimum phase difference), carry out the phase difference FEEDBACK CONTROL, but since wearing and tearing that cause because of the Continuous Drive of piezo-activator 20 and heating etc. through the time change, the vibration characteristics of piezo-activator 20 changes, and should change as the optimum phase difference self of index in the control of driving control device 50A, can not obtain suitable torque sometimes.

And, since this through the time change, phase difference reversal frequency F1 and clamp frequency F2 etc. also change, thereby influence drive controlling.

The drive characteristic of this piezo-activator 20 of the graphical representation of Figure 23 through the time change.

In the curve chart of Figure 23, utilize the rotating speed of the rotor 30 that solid line represents, the electric current and the phase difference of piezo-activator 20, it is respectively the value during turntable driving frequency (curve chart transverse axis) under the initial condition when piezo-activator 20 starting, in Figure 23, rotating speed, electric current, phase difference when turntable driving frequency behind 1 hour of this initial condition, after 3 hours utilize the different dotted line of line type to represent respectively.

Shown in this curve chart, the rotating speed during the turntable driving frequency, electric current and phase difference are non-constant, change along with effluxion from initial condition.In the present embodiment, near the resonance point of the vibrating body 20A of piezo-activator 20 (Figure 23 medium speed 2500rpm time driving frequency) is initially R ₀, but after 1 hour, be R ₁, be R after 3 hours ₃State improve gradually, so rotating speed, electric current and phase difference during the turntable driving frequency also move.As the main cause of their migrations, for example can consider rotor 30 and vibrating body 20A projection 25 wearing and tearing or make the variation etc. of the pressurized conditions such as bullet thrust of projection 25 butt rotors 30.

The drive characteristic of corresponding this piezo-activator 20 through the time change, phase difference FEEDBACK CONTROL process in actuation step P5 is during the stipulated time, the frequency control part 654 of controller 265 is judged to be elapsed time Tn and has reached Continuous Drive time N (the step Sn37 among Figure 21), implements the counter-rotating of optimum phase difference obtaining step P1 shown in Figure 20 and phase difference once more and detects step P4.That is, optimum phase difference obtaining step P1 repeated to implement according to each the Continuous Drive time (1 hour) in the controller 265 of being stored in, and was updated as the value of optimum phase difference defined.And phase difference counter-rotating detects step P4 and also repeats to implement according to each the Continuous Drive time (1 hour) that is stored in the controller 265, and the value that is kept at phase difference reversal frequency F1 in the storage part 658 and clamp frequency F2 etc. is updated.

Like this, corresponding through the time change and the skew of the resonance point that forms etc., correction remains value, phase difference reversal frequency F1 and the clamp frequency F2 etc. of optimum phase difference, so can reasonably to implement with the optimum phase difference be the drive controlling of driving control device 50A of prerequisite.

Herein, piezo-activator 20 constitutes by optionally providing drive signal to drive electrode 221,222,223 according to noted earlier, can forward and reverse driving rotor 30, but the phase difference of extensional vibration and flexural vibrations is synthetic, asymmetric to forward drive with to reverse driving the time, the situation that drive characteristic differs from one another is more.

Therefore, operate when clocking the forward counter-rotating direction of pointer 7A second and during through stipulated time and corrected time etc. the user, by forward counter-rotating circuit 522 (Figure 15) to controller 265 input expression be rotated in the forward/during the signal of the switching of counter-rotating (is "Yes" at Sn38), also implement the counter-rotating of optimum phase difference obtaining step P1 shown in Figure 20 and phase difference once more and detect step P4 (utilizing these steps P1 and P2 to constitute the initial setting step).

Figure 24 is the curve chart of drive characteristic of expression piezo-activator 20, and Figure 25 is in order to compare, be illustrated in the curve chart of the drive characteristic when not implementing the driving frequency restriction in this piezo-activator 20 with Figure 24.In these Figure 24, Figure 25, the Continuous Drive time of piezo-activator 20 is made as transverse axis.

When implementing the driving frequency restriction, although under the environment that is easy to generate vibrating body 20A heating owing to Continuous Drive, also as shown in figure 24, swinging up and down of driving frequency is suppressed, and the rotating speed of rotor 30 is also stable.To this, in Figure 25, as can be known,, driving frequency is changed up and down owing to follow the variations in temperature etc. of vibrating body 20A heating, in the part that changes up and down, the rotating speed of rotor 30 does not increase, and driving condition is very unstable.

That is, the restriction of the driving frequency by aforesaid driving control device 50, irrelevant with variations in temperature etc., can confirm that the drive controlling of piezo-activator 20 is stable.

[effect of 2-4. present embodiment]

According to present embodiment, the result who in the 1st execution mode, narrates, can also obtain following effect.

(6) the frequency control part 654 that utilizes controller 265 to have, implement optimum phase difference obtaining step P1 with the frequency of regulation, even thus for the needed optimum phase difference of the driving condition of realizing stipulating (driving the maximum needed optimum phase difference of efficient for making in the present embodiment) since through the time change grade and change, when implementing optimum phase difference obtaining step P1, can stipulate once more that also optimum phase difference is suitable optimum phase difference to proofread and correct.That is, can assure the well-formedness of optimum phase difference.Therefore, can in actuation step P2, make drive controlling become stable, can utilize to drive the desired driving efficient of rotor 30 needed torques realizations according to this optimum phase difference.

(7) in driving control device 50, when the frequency that makes drive signal is followed the phase difference that is detected by phase difference detection portion 60, utilize the table information TBL of phase difference counter-rotating test section 655 with reference to storage part 658, following phase difference rear drive frequency when reaching clamp frequency F2, utilize clamp portion 657 to clamp down on driving frequency, implement the driving frequency restriction the following of phase difference.Therefore, when the turntable driving frequency, under the situation that the size evaluation generation of the relative target phase difference θ of phase difference is reversed, also driving frequency can be changed to reciprocal abnormality processing and prevent trouble before it happens, can stably implement drive controlling.

(8) when controller 265 turntable driving frequencies, setting is offset to the clamp frequency F2 of optimal drive state G side from phase difference reversal frequency F1, the controlling and driving frequency is followed phase difference, make it can not become the value of this clamp frequency F2, even so driving condition is because the change of driving frequency and during near rollback point Pt1, also can prevent from reliably owing to the reversal development of phase difference evaluation driving frequency to be followed in inappropriate direction.

(9) electronic watch 1A has assembled driving control device 50A, so the action of actuator 20 can Yin Wendu and the change of load etc. and become unstable.

Herein, the variation to the 2nd execution mode of above explanation is illustrated.Following variation corresponds respectively to the variation 1～3 of the 1st execution mode.

[variation 1 of the 2nd execution mode]

Low-power consumption actuation step P7 shown in Figure 26 can be replaced as low-power consumption actuation step P6 shown in Figure 22 in aforementioned the 2nd execution mode.And this processing shown in Figure 26 is corresponding to the processing of the variation of conduct shown in Figure 11 the 1st execution mode.

Promptly, in aforementioned the 2nd execution mode, judge among (S61) initial value setting step S10 afterwards in the driving parameters initialization, the pulsewidth T that slave controller 265 is exported to the drive signal of pulse control circuit 52 is initialized as " 0% ", but be not limited thereto, as shown in Figure 26, also can utilize " 10% " as suitable pulsewidth etc. pulsewidth T initialization, adjust the pulsewidth of drive signal, become stable state up to setting rotating speed according to rotor 30.Thus, the starting time of piezo-activator 20 shortens, and can realize shortening priming speed and low-power consumption double effects.

In addition, the initial value of the pulsewidth of drive signal is not limited to suitable pulsewidth " 10% ", for example also can " 5% " etc. less than the pulsewidth of suitable pulsewidth as initial value, improve pulse duty factor gradually according to the rotating speed that is detected.

[variation 2 of the 2nd execution mode]

In addition, in the variation 1 of aforementioned the 2nd execution mode, with the variation 2 of aforementioned the 1st execution mode similarly, also can form following structure, in storage part 651, preserve suitable pulsewidth (for example 10%), when after starting, being in stable state, suitable pulsewidth is kept in the storage part 651 again, can also not utilize the pulsewidth when last time starting, and the pulsewidth of when repeatedly starting each drive signal when rotor 30 is in stable state when self-driven is kept in the storage part 651 as suitable pulsewidth.

[variation 3 of the 2nd execution mode]

And low-power consumption actuation step P8 shown in Figure 27 also can be replaced as low-power consumption actuation step P6 shown in Figure 22 in aforementioned the 2nd execution mode.And this processing shown in Figure 27 is corresponding to the processing of the variation of conduct shown in Figure 12 the 1st execution mode.

That is, when the control beginning initialization step S00 is set, the pulsewidth of scanning drive signal is obtained the rotating speed that is used to realize desired torque in this initialization step S00.

In addition, in the 2nd execution mode, also can realize the distortion identical with the variation 4,5 of aforementioned the 1st execution mode.

[the 3rd execution mode]

Below, the 3rd execution mode of the present invention is described.

In the present embodiment, the driven member that carries out adjusting piezo-activator 20 is the drive controlling of the rotating speed of rotor.

Figure 28 represents the driving control device 50B of present embodiment.

Driving control device 50B also has except the structure of aforementioned driving control device 50A (Figure 15): the rotary speed instruction value source 72 of the rotary speed instruction value of output rotor; With rotational speed governor 73, it is according to the rotary speed instruction value of rotating speed that is detected by revolution detector 71 and 72 outputs from rotary speed instruction value source, to controller 265 output control signals.

Figure 29 is the flow chart of the optimum phase difference obtaining step P1 ' of expression present embodiment.In optimum phase difference obtaining step P1 ', at first revolution detector 71 is set 0 (zero sets) (step Sn20).Then, with aforementioned optimum phase difference obtaining step P1 (Figure 20) similarly, implementation step Sn21～step Sn27 obtains optimum phase difference (Sn27).Then with Figure 20 similarly, implement the phase difference counter-rotating and detect step P4, and to elapsed time Tn reset (Sn28).During this Sn21～Sn28, the rotating speed of proceeding 71 pairs of rotors 30 of revolution detector detects.

And, utilize revolution detector 71, rotary speed instruction value source 72 and rotational speed governor 73 at last, making from moment beginning rotor rotated 30 counter-rotatings of step Sn20 becomes " 0 " (amount of movement reconstitution steps: step Sn29) up to rotating speed.Then, change actuation step P5 (Figure 21) over to, optimum phase difference obtaining step P1 ' and phase difference counter-rotating detect the command value of the needed time addition of step P4 gained, by the timing portion module input speed command value source 72 of circuit substrate, so utilize rotational speed governor 73 to adjust the rotating speed of rotor 30.

In addition, the rotating speed of 71 pairs of rotors 30 of revolution detector detects and also continues to implement in actuation step P5.

[variation of the present invention]

The invention is not restricted to aforementioned embodiments.More than restriction shows several variation about the pulsewidth of drive signal, but also allow to carry out without departing from the spirit and scope of the present invention various distortion and improvement about other aspects.

For example, as the structure of the rotary speed that can adjust rotor, show the 3rd execution mode that the rotating speed of a detection rotor is simultaneously controlled, but be not limited thereto, also can constitute the current value that detects piezo-activator, detect Control current, adjust the rotary speed of rotor thus according to this.And the rotating speed of all right detection rotor and the current value both sides of piezo-activator carry out the adjustment of the rotary speed of rotor according to them.

In addition, when the current value both sides of the rotating speed of detection rotor and piezo-activator control, for example based on the Control Circulation of rotor speed as master control, based on the Control Circulation of current value as sub-control, in structure with revolution detector, rotary speed instruction value source, rotational speed governor, current detector, current controller, according to from the rotary speed instruction value in rotary speed instruction value source and the rotating speed that detected by revolution detector, rotational speed governor generates current instruction value.And, also can constitute according to this electric current generation value and the current value that detects by current detector, current controller is exported control signal to control part.

And, driving control device 50 in aforementioned each execution mode, 50A controller 65,265 separately constitutes as control part, comprise FREQUENCY CONTROL portion, optimum phase difference acquisition unit, frequency control part, phase difference counter-rotating test section, clamp portion and storage part etc., but these various pieces can be installed in the different controllers, can at random constitute.Controller 65,265 not only utilizes hardware, also can utilize software to constitute.

In aforementioned embodiments, optimum phase difference is defined as the driving efficient maximum that makes piezo-activator, but be not limited thereto, in the situation that need not drive with maximum drive efficient etc. down, also can determine to be suitable for to drive efficient and be not the optimum phase difference of the driving condition of maximum, regulation.

And in aforementioned embodiments, the phase difference of feedback drive signal and detection signal makes the frequency of drive signal follow this phase difference, but also can not carry out this phase difference FEEDBACK CONTROL, is steady state value and make the fixed-frequency of drive signal.

In addition, in aforementioned embodiments, drive signal is a square wave, but is not limited thereto, and also can adopt sine wave, sawtooth waveforms, triangular wave etc. as the waveform of drive signal, can realize low-power consumption according to its pulse width control.

When in the initial setting step, obtaining optimum phase difference with the regulation frequency, the number of times that need utilize means gate time and number of starts arbitrarily, carries out compulsory exercise, but this moment also can be when drive pressure electric actuator not, value in during the counting is kept in the nonvolatile memory etc., when starting piezo-activator once more, increase the value that count down to midway.Thus, when starting, piezo-activator do not need unconditionally to implement the optimum phase difference obtaining step, the driving of piezo-activator with short interval (during) repeat, under the situation of driving time and number of times accumulative total, also can implement obtaining of the optimum phase difference that can change reliably with the frequency of regulation according to state of wear etc.

And, by the enforcement frequency of the optimum phase difference obtaining step P1 of regularization, be per 1 hour by the frequency control part in aforementioned each execution mode, but be not limited to 1 hour as the time that frequency sets.According to the payload of driven member etc., for example somewhat～suitably determine in several hours the scope.And it is big more also can to study from the elapsed time of initial condition when long more frequency, that is, reduce the time interval to implement optimum phase difference obtaining step etc., determines frequency according to the length in elapsed time.

In addition, the enforcement frequency of optimum phase difference obtaining step also can be according to will usually stipulate beyond the time.That is, can for example frequency be made as number of starts 255 times, and be stored in the storage part of controller according to definite frequency such as number of starts of piezo-activator.And, also can be when piezo-activator be mounted on the electronic equipment regulation frequency.When this assembles, also comprise the replacing of the piezo-activator of the generations such as wearing and tearing of following the abutting part between vibrating body and the driven member.

Definite method of frequency is suitably determined according to the load of driven member and the pattern of piezo-activator etc.Also can according to the rotor of narrating previously be rotated in the forward or each direction of rotation of counter-rotating is determined frequency.

The invention is not restricted to be applicable to the electronic equipment of aforementioned embodiments, also go for various electronic equipments, be particularly suitable for requiring the portable electric appts of miniaturization.

As various electronic equipments, can enumerate phone with clock function, portable phone, contactless IC card, computer, portable data assistance (PDA), camera etc. herein.

And, also go for not having camera, digital camera, the video camera of clock function, the electronic equipments such as portable phone of band camera-enabled.When being applicable to these electronic equipments with camera-enabled, the driving of the focusing of lens, zoom mechanism, aperture adjusting mechanism etc. can be used drive division of the present invention.

In addition, the driving mechanism of touchable toy classes such as the driving mechanism of the gauge pointer of panel boards such as the driving mechanism of the gauge pointer of testing equipment, automobile, sheet feed mechanism of printer, movable idol etc. also can use driving control device of the present invention.

And, in aforementioned embodiments, piezo-activator 20 has been used in the driving of the device displaying calendar date 90 of expression calendar, but be not limited thereto, the drivings of the hour hands 4 in the driving of the calendar mechanism in demonstration year, the moon, week and the expression moment, minute hand 5, second hand 6 etc. also can be used piezo-activator of the present invention.

In addition, in aforementioned each execution mode, enumerated wrist-watch as the suitable example of piezo-activator, but be not limited thereto, the present invention also goes for pocket-watch, desk clock, wall clock etc.

In addition, as driven member, can adopt and be driven rotor rotated, be driven straightaway Linear Driving body etc., the driving direction of driven member is unqualified.

Be used for implementing optimum structure of the present invention, method etc. and disclose, but the invention is not restricted to this in above record.That is, the invention is not restricted to main specific execution mode, for the execution mode of above narration, about shape, material, quantity and other concrete structures, industry personnel can carry out various distortion.

Therefore, define the record of above disclosed shape, material etc., the just exemplary record of doing for the ease of understanding the present invention, can not limit the present invention, therefore the record of adopting the component names of part or all qualification that has broken away from qualifications such as these shapes, material to carry out also is contained among the present invention.

Claims (14)

1. the drive controlling method of a piezo-activator, the vibrating body that provides drive signal to vibrate by to piezoelectric element is provided this piezo-activator, and gives driven member with the transfer of vibration of described vibrating body, it is characterized in that,

Described vibrating body is according to the supply of square wave and single-phase described drive signal, with the synthesis mode vibration of a plurality of vibration modes,

Described piezo-activator produces described drive signal to realize the benchmark pulsewidth of the determined maximum driving force of drive characteristic when driving described driven member,

With respect to described benchmark pulsewidth,, limit the pulsewidth of described drive signal to realize that the minimum pulse width in order to drive the needed MIN minimum actuating force of described driven member according to described drive characteristic is a limit.

2. the drive controlling method of piezo-activator according to claim 1 is characterized in that,

Described vibrating body forms roughly rectangular shape when overlooking,

Described a plurality of vibration modes of described vibrating body are along the flexible extensional vibration of the length direction of described vibrating body and the flexural vibrations of relative described length direction bending.

3. the drive controlling method of piezo-activator according to claim 1 and 2 is characterized in that,

Scan the pulsewidth of described drive signal, obtain the suitable pulsewidth of the actuating force that realizes described regulation,

Described drive signal is controlled to be described suitable pulsewidth.

4. the drive controlling method of piezo-activator according to claim 1 and 2 is characterized in that,

When starting with the pulsewidth initialization of the suitable pulsewidth of the actuating force that realizes described regulation with described drive signal.

5. the drive controlling method of piezo-activator according to claim 4 is characterized in that,

Based on the pulsewidth of the described drive signal of described driven member when becoming stable state when the driving of last time starting, determine described suitable pulsewidth.

6. the drive controlling method of piezo-activator according to claim 1 and 2 is characterized in that,

According to the detection of the driving condition of this piezo-activator, adjust the pulsewidth of described drive signal.

7. the drive controlling method of piezo-activator according to claim 6 is characterized in that,

Except that the actuation step of the pulsewidth that limits described drive signal with respect to described benchmark pulsewidth, this method also comprises the initial setting step, and this initial setting step has:

The optimum phase difference obtaining step, it is about described drive signal and represent phase difference between the detection signal of described detected driving condition, implement the frequency scanning of described drive signal, obtain optimum phase difference as the phase difference of the driving condition of realizing regulation;

The phase difference counter-rotating detects step, it detects the phase difference between described drive signal and the described detection signal, in the prescribed limit of the frequency that comprises the driving condition of realizing described regulation, implement simultaneously the frequency scanning of described drive signal along prescribed direction, at this moment, phase difference reversal frequency when detecting described phase difference and reaching described optimum phase difference once more

In described actuation step, limit according to described phase difference reversal frequency, make the frequency of described drive signal can not reach the clamp frequency that in the value of the driving condition side of described regulation, sets, detect the phase difference between described drive signal and the described detection signal simultaneously, and according to described phase difference with respect to described optimum phase extent, the frequency of described drive signal is changed to high or low, make the frequency of described drive signal follow described phase difference thus

Frequency with regulation carries out described initial setting step, upgrades described optimum phase difference and described phase difference reversal frequency respectively.

8. piezoelectric actuator drive control device, the vibrating body that provides drive signal to vibrate by to piezoelectric element is provided this piezo-activator, and gives driven member with the transfer of vibration of described vibrating body, it is characterized in that,

Described vibrating body is according to the supply of square wave and single-phase described drive signal, with the synthesis mode vibration of a plurality of vibration modes,

This piezoelectric actuator drive control device has:

Source driving signal, it makes described piezo-activator to realize the benchmark pulsewidth of the determined maximum driving force of drive characteristic when driving described driven member, produces described drive signal, and

Control part, it to realize that the minimum pulse width in order to drive the needed MIN minimum actuating force of described driven member according to described drive characteristic is a limit, limits the pulsewidth of described drive signal with respect to described benchmark pulsewidth.

9. piezoelectric actuator drive control device according to claim 8 is characterized in that,

Described vibrating body forms roughly rectangular shape when overlooking,

Described a plurality of vibration modes of described vibrating body are along the flexible extensional vibration of the length direction of described vibrating body and the flexural vibrations of relative described length direction bending.

10. according to Claim 8 or 9 described piezoelectric actuator drive control device, it is characterized in that,

This piezoelectric actuator drive control device has the storage part of the suitable pulsewidth of storing the actuating force that realizes described regulation.

11. according to Claim 8 or 9 described piezoelectric actuator drive control device, it is characterized in that,

This piezoelectric actuator drive control device has the test section of the driving condition that detects this piezo-activator,

Described control part is adjusted the pulsewidth of described drive signal according to described driving condition.

12. piezoelectric actuator drive control device according to claim 11 is characterized in that, this piezoelectric actuator drive control device comprises:

Initial setting section, it has: phase difference detection portion, this phase difference detection portion detect described drive signal and represent by the phase difference between the detection signal of the driving condition that described test section detected; The optimum phase difference acquisition unit, this optimum phase difference acquisition unit is implemented the frequency scanning of described drive signal, according to the detection of described phase difference detection portion to described phase difference, obtains the optimum phase difference as the phase difference of the driving condition of realizing regulation; With phase difference counter-rotating test section, this phase difference counter-rotating test section detects the phase difference between described drive signal and the described detection signal, in the prescribed limit of the frequency that comprises the driving condition of realizing described regulation, implement simultaneously the frequency scanning of described drive signal along prescribed direction, phase difference reversal frequency when at this moment, detecting described phase difference and reach described optimum phase difference once more;

FREQUENCY CONTROL portion, it sets the frequency of described drive signal according to described optimum phase difference; And

The frequency control part, its frequency with regulation carries out the processing of described initial setting section, thereby upgrades described optimum phase difference and described phase difference reversal frequency respectively,

Described FREQUENCY CONTROL portion has clamp portion, this clamp portion limits according to described phase difference reversal frequency, make the frequency of described drive signal can not reach the clamp frequency that in the value of the driving condition side of described regulation, sets, described FREQUENCY CONTROL portion implements the frequency limitation of described clamp portion to described drive signal, detect described phase difference by described phase difference detection portion simultaneously, and according to described phase difference with respect to described optimum phase extent, the frequency of described drive signal is changed to high or low, make the frequency of described drive signal follow described phase difference thus.

13. an electronic equipment is characterized in that this electronic equipment has: piezo-activator; The driven member that is driven by this piezo-activator; And the described piezoelectric actuator drive control device of claim 8.

14. electronic equipment according to claim 13 is characterized in that, this electronic equipment is to have timing portion and show clock and watch by the clocking information display part of the clocking information of described timing portion timing.

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