`(12) Patent Application Publication (10) Pub. No.: US 2004/0169480 A1
`Ueda et al.
`(43) Pub. Date:
`Sep. 2, 2004
`
`US 2004O1694.80A1
`
`(54) CONTROL SYSTEM FOR A LINEAR
`VIBRATION MOTOR
`
`(76) Inventors: Mitsuo Ueda, Nishinomiya-shi (JP);
`Hideki Nakata, Shijyonawate-shi (JP);
`Makoto Yoshida, Kusatsu-shi (JP)
`
`Correspondence Address:
`WENDEROTH, LIND & PONACK, L.L.P.
`2033 K STREET N. W.
`SUTE 800
`WASHINGTON, DC 20006-1021 (US)
`
`(21) Appl. No.:
`(22) PCT Filed:
`(86) PCT No.:
`
`10/483,720
`Jul. 15, 2003
`PCT/JP03/08958
`
`Foreign Application Priority Data
`(30)
`Jul. 16, 2002 (JP)...................................... 2002-2O7467
`
`Publication Classification
`
`(51) Int. Cl." ....................................................... H02P 1100
`(52) U.S. Cl. .............................................................. 318/114
`(57)
`ABSTRACT
`A motor driving apparatus for driving a linear Vibration
`motor is provided with an order output determining unit for
`determining a motor output required of the linear Vibration
`motor, and a driving frequency determining unit for deter
`mining a driving frequency of the linear Vibration motor on
`the basis of the determined motor output, and an amplitude
`fixed AC voltage having a frequency equal to the determined
`driving frequency is applied to the linear Vibration motor,
`whereby the output of the linear vibration motor can be
`controlled without changing the amplitude value of the
`driving Voltage applied to the linear Vibration motor.
`
`1 O
`
`
`
`
`
`external
`power Supply
`
`
`
`Vd
`
`OO
`
`vibration motor
`
`
`
`
`
`driving frequency
`determining unit
`
`order output
`determining unit
`
`
`
`Exhibit 1008 - Page 1 of 40
`
`
`
`Patent Application Publication Sep. 2, 2004 Sheet 1 of 12
`
`US 2004/016948.0 A1
`
`Fig.1
`
`1O
`
`Vp
`
`
`
`
`
`external
`power Supply
`
`101
`
`VC
`
`1OO
`
`Fig.2
`
`
`
`O
`
`Vp -- VC
`
`100
`
`external
`power Supply
`
`
`
`driving
`frequency
`determining
`unit
`
`
`
`Exhibit 1008 - Page 2 of 40
`
`
`
`Patent Application Publication Sep. 2, 2004 Sheet 2 of 12
`
`US 2004/016948.0 A1
`
`Fig.3 (a)
`10
`external
`power Supply
`
`ve. .
`
`. .
`
`Vd.
`
`190
`
`
`
`driving
`frequency
`determining
`unit
`
`
`
`
`
`
`
`eSOaCe
`frequency
`determining unit
`
`Fig.3(b)
`
`driving frequency
`(Fx)
`
`
`
`Pb2
`
`Pb
`
`Pin
`
`detected position
`(Px)
`
`Fig.3 (c)
`
`driving frequency
`(Fx)
`
`
`
`Fmax
`FreSO
`
`Prb
`
`Pru Pim
`
`detected position
`(Px)
`
`Exhibit 1008 - Page 3 of 40
`
`
`
`Patent Application Publication Sep. 2, 2004 Sheet 3 of 12
`Fig.4 (a)
`
`O
`
`a
`
`Vp
`-
`
`O4
`
`Vd
`
`100
`
`US 2004/016948.0 A1
`
`* .
`
`external
`
`power Supply 7
`
`M
`
`motor
`
`7
`
`linear
`
`--------- y
`
`--Prm
`driver for to
`----2SP
`2C
`:
`:
`
`driving frequency
`determining unit
`
`3
`
`OdV
`7
`
`Dposi
`
`Dreso
`
`p
`
`L
`
`Output
`detector.
`
`order output
`determining unit
`
`driving voltage
`determining unit
`
`4.
`DoD
`p
`
`Oop : :
`
`position
`detector
`
`.......
`
`reSOranCe
`frequency
`
`determining unit
`
`6
`
`J
`
`Fig.4 (b)
`
`
`
`allowable stroke state
`
`over stroke state
`
`The detected
`output is smaller
`than the required
`motor output.
`
`The amplitude value
`of AC voltage Vd is
`increased.
`
`The amplitude value of AC
`Voltage Vod is adjusted so
`that the position of mover is
`within predetermined range.
`
`The amplitude value
`The detected
`of AC voltage Vod is
`output is larger
`than the required \decreased.
`motor output.
`
`The amplitude value
`of AC voltage Vd is
`decreased.
`
`DS3
`
`DS4
`
`DS1
`
`DS2
`
`Exhibit 1008 - Page 4 of 40
`
`
`
`Patent Application Publication Sep. 2, 2004 Sheet 4 of 12
`
`US 2004/016948.0 A1
`
`Fig.5 (a)
`-
`O
`
`O5
`
`Vp
`
`a
`
`Vc
`
`d
`
`1 OO
`
`external
`
`motor
`
`of His reacto
`
`linear
`
`pop
`
`4
`
`detector
`
`Oop
`
`determining unit
`
`2d
`
`driving frequency
`determining unit
`
`3
`
`Odv
`
`Dreso
`
`determining unit
`resonance
`frequency
`determining unit
`
`7
`
`6
`
`-
`
`- - - - - - - - - - - - - - - -
`
`Fig.5 (b)
`
`driving frequency
`(Fx)
`
`FreSO
`
`Fig.5 (c)
`
`driving frequency
`(Fx)
`
`
`
`Fmax
`Freso
`
`determined
`amplitude value
`(Ax)
`
`O
`
`Arb
`
`Aru Alim
`
`determined
`amplitude value
`(Ax)
`
`Exhibit 1008 - Page 5 of 40
`
`
`
`Patent Application Publication Sep. 2, 2004 Sheet 5 of 12
`
`US 2004/0169480 A1
`
`Fig.6 (a)
`
`
`
`Fig.6 (b)
`
`(ULld(t) R-Id()
`H
`
`Exhibit 1008 - Page 6 of 40
`
`
`
`Patent Application Publication Sep. 2, 2004
`
`Sheet 6 of 12
`
`US 2004/0169480 A1
`
`
`
`
`|- T - (m)
`
`Áouenbeu,
`?oueuose)
`>Kouanbºu,
`fiu?a?up
`
`| • HA - 20æ:----
`
`(p) / 61-(0) / 61
`
`Exhibit 1008 - Page 7 of 40
`
`
`
`Patent Application Publication Sep. 2, 2004 Sheet 7 of 12
`
`US 2004/016948.0 A1
`
`Fig.8 (a)
`1 O
`
`Vp
`
`1a
`
`Vc
`
`100
`
`external
`
`M
`
`motor
`
`t
`
`linear
`
`part is 5 Terra
`n-9mp l. Dop
`
`
`
`driving voltage
`
`tput
`
`4.
`
`driving frequency
`determining unit
`
`
`
`Dov
`
`Odv
`
`order output
`determining unit
`
`driving voltage
`determining unit
`
`Dreso
`
`reSOrnance
`frequency
`determining unit
`
`Oop
`
`7
`
`6
`
`Fig.8 (b)
`driving frequency
`(Fx)
`
`
`
`detected voltage value
`(Vx)
`
`O
`
`Vb2
`
`Vb
`
`Vim
`
`Fig.8 (c)
`driving frequency
`(Fx)
`
`
`
`Flax
`Freso
`
`Vrb
`
`Viru Vlim
`
`detected voltage value
`(Vx)
`
`Exhibit 1008 - Page 8 of 40
`
`
`
`Patent Application Publication Sep. 2, 2004 Sheet 8 of 12
`
`US 2004/0169480 A1
`
`
`
`
`
`
`CO
`r
`
`Exhibit 1008 - Page 9 of 40
`
`
`
`Patent Application Publication Sep. 2, 2004 Sheet 9 of 12
`Fig.10
`
`US 2004/016948.0 A1
`
`
`
`Exhibit 1008 - Page 10 of 40
`
`
`
`Patent Application Publication Sep. 2, 2004 Sheet 10 of 12
`
`US 2004/0169480 A1
`
`Fig.ii
`
`
`
`209
`
`71
`
`D
`
`Fig.12
`
`1 O
`
`7Ob
`
`
`
`nOtOr
`driving unit
`
`Exhibit 1008 - Page 11 of 40
`
`
`
`Patent Application Publicat
`
`ion Sep. 2, 2004 Sheet 11 of 12
`
`US 2004/0169480 A1
`
`
`
`
`1088
`
`Exhibit 1008 - Page 12 of 40
`
`
`
`Patent Application Publication Sep. 2, 2004 Sheet 12 of 12
`
`US 2004/0169480 A1
`
`Fig.14
`
`
`
`90a
`
`212
`
`Exhibit 1008 - Page 13 of 40
`
`
`
`US 2004/01694.80 A1
`
`Sep. 2, 2004
`
`CONTROL SYSTEM FOR A LINEAR VIBRATION
`MOTOR
`
`TECHNICAL FIELD
`0001. The present invention relates to motor driving
`apparatuses and, more particularly, to a motor driving appa
`ratus for driving a linear Vibration motor having a mover and
`a Spring member for Supporting the mover.
`
`BACKGROUND ART
`0002 Conventional equipment using linear vibration
`motors include Vibration generators for informing incoming
`calls by mechanical vibration, Such handy phones, compres
`Sors for compressing -and circulating gases or fluids, and
`reciprocating electric razors. The compressors and electric
`razors use the linear Vibration motors as their driving
`SOUCCS.
`0003) A typical linear vibration motor has a structure of
`a single-phase Sync motor, that is, it has a mover comprising
`a permanent magnet and a Stator obtained by winding a coil
`around an iron core, and the mover reciprocates when an AC
`Voltage is applied to the coil.
`0004. As described above, when generating vibration by
`reciprocating motion of the mover, a strong electromagnetic
`force is needed. However, an energy required for driving the
`linear Vibration motor can be minimized by forming a Spring
`vibration system including the mover and a spring member
`Supporting the mover. That is, in the linear Vibration motor
`in which the mover is Supported by the Spring member, the
`Spring vibration System including the mover is vibrated at its
`natural resonance frequency, whereby the linear Vibration
`motor can be driven with a relatively low energy.
`0005. As a method for controlling an output of the linear
`vibration motor in which the mover is supported with the
`Spring, the amplitude value of a Voltage or current Supplied
`to the linear vibration motor may be adjusted while driving
`the linear vibration motor with its resonance frequency (for
`example, refer to Japanese Published Patent Application No.
`2001-193993).
`0006. In the linear vibration motor, however, when the
`Stroke length of the mover becomes larger than a predeter
`mined allowable value, a problem Such as a collision
`between the mover and the motor body or breakage of the
`Support Spring may occur. Therefore, the Stroke length of the
`mover is restricted by the structure of the linear vibration
`motor.
`0007 For example, when the extension of the support
`Spring exceeds a predetermined value due to an increase in
`the Stroke length-of the mover, the Support Spring may occur
`plastic deformation to be broken. Further, when the stroke
`length of the mover is increased to about the size of the
`motor body in the mover Vibrating direction, the mover may
`collide against the inner wall of the motor body to be broken.
`0008 So, there has been proposed an apparatus for driv
`ing a linear Vibration motor which Solves the above-men
`tioned problems. That is, this linear vibration motor driving
`apparatus is provided with a detector Such as a position
`Sensor for detecting the position of the mover of the linear
`Vibration motor, and reduces the output of the linear Vibra
`tion motor when the Stroke length of the mover exceeds a
`
`predetermined allowable value, that is, decreases the ampli
`tude value of the Voltage or current applied to the linear
`vibration motor, thereby preventing the linear vibration
`motor from being destroyed due to a collision between the
`mover and the motor body or extension of the Support Spring
`over a critical value (for example, refer to Japanese Pub
`lished Patent Application No. Hei. 11-324911).
`0009. However, since the conventional linear vibration
`motor driving apparatus (hereinafter also referred to as a
`motor driving apparatus) drives the linear vibration motor
`with the frequency of the reciprocating motion being main
`tained at the resonance frequency of the Spring vibration
`System including the mover, adjustment of the output of the
`linear Vibration motor is carried out by only the Stroke length
`of the mover. As a result, the maximum output of the linear
`vibration motor is undesirably restricted by the structure of
`the linear Vibration motor, and further, the maximum output
`of the linear vibration motor is undesirably restricted by the
`power Supply Voltage applied to the motor driving appara
`tuS.
`0010 First of all, restriction on the motor output by the
`structure of the linear vibration motor will be described in
`detail.
`0011. In the linear vibration motor, the maximum stroke
`length of the mover can be increased up to only the shorter
`one between the length of the body of the linear vibration
`motor containing the mover in the mover vibration direction,
`and the length corresponding to the elastic limit of the mover
`Supporting Spring.
`0012. Accordingly, in order to increase the maximum
`output of the linear vibration motor, the size of the motor
`body in the mover vibrating direction should be increased to
`Secure a larger Stroke length of the mover and, further, a
`Spring having a larger elastic limit length should be used as
`the mover Supporting Spring. Alternatively, the Spring con
`Stant of the mover Supporting Spring should be increased to
`increase the resonance frequency of the linear Vibration
`motor.
`0013. Accordingly, in the conventional linear vibration
`motor, the mechanical construction is determined on the
`basis of the required maximum output, and therefore, an
`increase in the maximum output may lead to not only an
`increase in Size but also a reduction in motor efficiency in an
`output region of the highest frequency of use, i.e., a reduc
`tion in the ratio of the motor output to the motor input.
`0014. The above-mentioned problem will be specifically
`described taking, as an example, a case where the linear
`Vibration motor is applied to a compressor of an air condi
`tioner. In this case, an output region of the highest frequency
`of use is not a high output region where a high motor output
`is generated for rapid heating operation or rapid cooling
`operation but a low output region where the motor output is
`about 10-20% of the motor output in the high output region.
`In the low output region, Since the Stroke length of the mover
`is reduced, the motor efficiency is reduced. Further, in the
`compressor, the top clearance is extended due to a reduction
`in the Stroke length of a piston, leading to a reduction in
`work efficiency.
`0015) Next, restriction on the motor output by the power
`supply voltage of the linear vibration motor will be
`described in detail.
`
`Exhibit 1008 - Page 14 of 40
`
`
`
`US 2004/01694.80 A1
`
`Sep. 2, 2004
`
`0016. In the conventional motor driving apparatus
`described above, the value of the applied Voltage is adjusted
`by intermittently applying the driving Voltage to the linear
`vibration motor So that the mover has a desired stroke
`length. To be specific, when the output power required of the
`linear Vibration motor is increased, the value of the Voltage
`applied to the linear Vibration motor is increased to increase
`the stroke length of the mover.
`0.017. However, when a general inverter is used for the
`motor driving apparatus, the motor driving apparatus cannot
`output an AC voltage whose amplitude value is larger than
`the voltage level of an inputted DC voltage. In other words,
`even when the amplitude value of the driving Voltage
`applied to the linear Vibration motor is increased to increase
`the Stroke length of the mover, the motor driving apparatus
`can apply only an AC voltage whose amplitude value is
`equal to or lower than the Voltage level of the input Voltage,
`to the linear vibration motor. As a result, the maximum
`output of the linear vibration motor is restricted by the
`Voltage level of the DC voltage applied to the motor driving
`apparatuS.
`0.018. In this case, in order to increase the maximum
`output of the linear Vibration motor, there is no choice but
`reducing the number of winding of the coil which is a
`component of the stator of the linear vibration motor. That
`is, by reducing the number of winding of the coil, the
`magnitude of an induced Voltage generated by the linear
`vibration motor is changed, whereby the balance between
`the driving Voltage and the driving current, i.e., the driving
`power that is a product of the driving current and the driving
`Voltage, is changed.
`0.019
`Accordingly, in the conventional linear vibration
`motor, the number of winding of the coil as a component of
`the stator of the linear vibration motor is determined on the
`basis of the required maximum output, leading to a possi
`bility that the motor efficiency might be reduced in the
`output region of the highest frequency of use.
`0020 For example, when the number of winding of the
`motor coil is reduced to increase the maximum output of the
`linear driving motor, the amount of current in the output
`region of the highest frequency of use, i.e., in the output
`region where the motor output power is low, is increased,
`resulting in a reduction in motor efficiency due to an increase
`in copper loSS or core loSS in the motor, or an increase in loSS
`in the inverter.
`0021. The present invention is made to solve the above
`described problems and has for its object to provide a motor
`driving apparatus which can control the motor output in the
`State where the Voltage level of the driving Voltage of the
`linear Vibration motor is kept constant, thereby to facilitate
`output control for the linear vibration motor, and which can
`increase the maximum output of the linear Vibration motor
`without modifying the Specifications of the linear Vibration
`motor or the power Supply thereof.
`
`DISCLOSURE OF THE INVENTION
`0022. According to the present invention (claim 1), there
`is provided a motor driving apparatus for driving a linear
`Vibration motor having a mover which is reciprocatably
`provided, and a Spring member which Supports the mover,
`and the apparatus includes a motor driver for Supplying an
`
`AC Voltage as a driving Voltage to the linear Vibration motor,
`which motor driver controls at least one of a motor output of
`the linear vibration motor and a stroke of the mover by
`adjusting a frequency of the AC voltage. Therefore, the
`motor output can be adjusted with the driving Voltage of the
`linear Vibration motor being kept constant, whereby the
`maximum output of the linear Vibration motor can be
`increased without modifying the Specifications of the linear
`Vibration motor or the power Supply thereof.
`0023. Further, since the output of the linear vibration
`motor or the Stroke of the mover is changed by adjusting the
`frequency of the AC voltage, output control for the linear
`vibration motor or stroke control for the mover can be easily
`carried out using a Voltage-controlled oscillator or the like as
`an oscillator incorporated in the motor driver, by changing
`a control Voltage for the Voltage-controlled oscillator.
`0024. According to the present invention (claim 2), the
`motor driving apparatus according to claim 1 further
`includes a target output determining unit for determining a
`target output as a motor output required of the linear
`Vibration motor; and a driving frequency determining unit
`for determining a driving frequency of the linear Vibration
`motor on the basis of the determined target output; and the
`motor driver controls the motor output by adjusting the
`frequency of the AC voltage Supplied to the linear Vibration
`motor So as to be equal to the driving frequency determined
`by the driving frequency determining unit. Therefore, the
`output of the linear vibration motor can be brought to the
`target output without considerably changing the amplitude
`level of the AC voltage supplied to the linear vibration
`motor.
`0025. According to the present invention (claim 3), the
`motor driving apparatus according to claim 2 further
`includes an output detection unit for detecting the motor
`output of the linear vibration motor; and the driving fre
`quency determining unit determines the driving frequency
`So that a difference between the detected motor output and
`the determined target output becomes Zero. Therefore, out
`put control for the linear vibration motor becomes feedback
`control in which the motor output required of the linear
`Vibration motor is the target output, whereby output control
`for the linear vibration motor or stroke control for the mover
`can be performed with Stability and accuracy.
`0026. According to the present invention (claim 4), the.
`motor driving apparatus according to claim 1 further
`includes a driving frequency determining unit for determin
`ing a driving frequency of the linear Vibration motor; and a
`position detection unit for detecting a position of the mover;
`and the driving frequency determining unit Sets the driving
`frequency at a resonance frequency which brings a Spring
`Vibration System including the mover into a resonance State
`when the detected position of the mover does not exceed a
`predetermined reference position, and Sets the driving fre
`quency at a frequency higher than the resonance frequency
`when the detected position of the mover exceeds the refer
`ence position; and the motor driver controls the Stroke of the
`mover by adjusting the frequency of the AC Voltage Supplied
`to the linear Vibration motor So as to be equal to the driving
`frequency determined by the driving frequency determining
`unit. Therefore, under the state where the Stoke of the mover
`is within an allowable range, the linear Vibration motor can
`be driven at high efficiency by Setting the driving efficiency
`
`Exhibit 1008 - Page 15 of 40
`
`
`
`US 2004/01694.80 A1
`
`Sep. 2, 2004
`
`at the resonance efficiency. Moreover, even in a high output
`region where the Stroke of the mover might exceed the
`allowable range if the linear vibration motor is driven at the
`resonance frequency, the linear motor can be driven with the
`Stroke of the mover being restricted to the allowable range.
`0027) According to the present invention (claim 5), in the
`motor driving apparatus according to claim 4, the driving
`frequency determining unit changes the driving frequency to
`a frequency at which the detected position of the mover does
`not exceed the reference position when the detected position
`of the mover exceeds the reference position. Therefore, in a
`high output region where the Stroke of the mover might
`exceed an allowable range if the linear vibration motor is
`driven at the resonance frequency, the driving frequency is
`Set at a frequency closest to the resonance frequency, at
`which the stroke of the mover does not exceed the allowable
`range, whereby the linear Vibration motor can be driven at
`maximum efficiency while preventing a collision of the
`mover or extension of the Support Spring over its elastic
`limit. Furthermore, Since, in the high output region, the
`driving frequency is Set at a frequency closest to the reso
`nance frequency, at which the Stroke of the mover does not
`exceed the allowable range, when the motor output required
`of the linear Vibration motor is decreased, the driving
`frequency can be Smoothly returned to the resonance fre
`quency.
`0028. According to the present invention (claim 6), the
`motor driving apparatus according to claim 4 further
`includes a target output determining unit for determining a
`target output as a motor output required of the linear
`Vibration motor; an output detection unit for detecting the
`motor output of the linear Vibration motor; and a driving
`Voltage determining unit for determining a target Voltage
`value of the driving voltage of the linear vibration motor so
`that a difference between the detected motor output and the
`determined target output becomes Zero; and the motor driver
`adjusts the frequency and Voltage value of the AC Voltage
`Supplied to the linear Vibration motor So that the Voltage
`value of the AC voltage becomes equal to the target Voltage
`value determined by the driving Voltage determining unit,
`and the frequency of the AC Voltage becomes equal to the
`driving frequency determined by the driving frequency
`determining unit. Therefore, output control for the linear
`vibration motor becomes feedback control in which the
`Voltage value of the driving Voltage is adjusted with the
`motor output required of the linear vibration motor being the
`target output, whereby output control for the linear Vibration
`motor can be carried out with high accuracy, Stability, and
`responsivity, while keeping the Stroke of the mover within
`an allowable range.
`0029 According to the present invention (claim 7), in the
`motor driving apparatus according to any of claims 4 to 6,
`the reference position is determined on the basis of an elastic
`limit value of the Spring member Supporting the mover.
`Therefore, even when a high motor output is required, the
`required motor output can be generated while Suppressing
`the Stroke length of the mover to an extent that the extension
`of the Support Spring of the mover does not exceed the
`elastic limit value. As a result, the reliability of the linear
`Vibration motor can be enhanced, as well as the linear
`Vibration motor can be driven even in a high output region
`
`where driving of the linear Vibration motor at the resonance
`frequency is impossible due to the elastic limit of extension
`of the Support Spring.
`0030. According to the present invention (claim 8), in the
`motor driving apparatus according to any of claims 4 to 6,
`the reference position is determined on the basis of a
`position in which the mover might collide with parts con
`Stituting the linear Vibration motor, or parts of a device
`containing the linear vibration motor. Therefore, even when
`a high motor output is required, the required motor output
`can be generated by Suppressing the Stroke length of the
`mover to an extent that the mover does not collide with the
`parts of the linear Vibration motor or the parts of equipment
`in which the linear Vibration motor is incorporated. AS a
`result, the reliability of the linear vibration motor can be
`enhanced, as well as the linear Vibration motor can be driven
`even in a high output region where driving of the linear
`Vibration motor at the resonance frequency is impossible due
`to the size of the motor body in the mover vibrating
`direction.
`0031. According to the present invention (claim 9), the
`motor driving apparatus according to claim 1 further
`includes a driving frequency determining unit for determin
`ing a driving frequency of the linear Vibration motor; a target
`output determining unit for determining a target output as a
`motor output required of the linear Vibration motor; an
`output detection unit for detecting the motor output of the
`linear vibration motor; and a driving Voltage determining
`unit for determining a target Voltage value of the driving
`voltage of the linear vibration motor so that a difference
`between the detected motor output and the determined target
`output becomes Zero; and the driving frequency determining
`unit Sets the driving frequency at a resonance frequency
`which brings a Spring vibration System including the mover
`into a resonance State when the determined target Voltage
`value does not exceed a predetermined reference value, and
`Sets the driving frequency at a frequency higher than the
`resonance frequency when the determined target Voltage
`value exceeds the reference value; and the motor driver
`controls the motor output and the stroke of the mover by
`adjusting the frequency and Voltage value of the AC Voltage
`Supplied to the linear Vibration motor So that the Voltage
`value of the AC voltage becomes equal to the target Voltage
`value determined by the driving Voltage determining unit,
`and the frequency of the AC Voltage becomes equal to the
`driving frequency determined by the driving frequency
`determining unit. Therefore, the linear Vibration motor can
`be efficiently driven at the resonance frequency until the
`required motor output reaches the maximum output at which
`driving of the linear Vibration motor at the resonance fre
`quency is restricted by the Voltage level of the power Supply.
`Furthermore, in a high output region where the required
`motor output exceeds the maximum output, the linear Vibra
`tion motor can be driven at a frequency higher than the
`resonance frequency without a considerable reduction in the
`driving efficiency.
`0032. Furthermore, output control for the linear vibration
`motor becomes feedback control in which the Voltage value
`of the driving Voltage is adjusted with the motor output
`required of the linear Vibration motor being the target output,
`whereby output control for the linear vibration motor can be
`carried out with high accuracy, Stability, and responsivity.
`
`Exhibit 1008 - Page 16 of 40
`
`
`
`US 2004/01694.80 A1
`
`Sep. 2, 2004
`
`0033 According to the present invention (claim 10), in
`the motor driving apparatus according to claim 9, the
`reference value is determined on the basis of the Voltage
`value of a DC power Supply provided for the motor driver;
`and the driving frequency determining unit changes the
`driving frequency to a frequency at which the determined
`target Voltage value does not exceed the reference value
`when the determined target Voltage value exceeds the ref
`erence value. Therefore, in a high output region where the
`motor output exceeds the maximum output restricted by the
`power Supply Voltage, the driving frequency is Set at a
`frequency closest to the resonance frequency, whereby
`highly efficient driving of the linear vibration motor is
`realized. Further, when the motor output required of the
`linear vibration motor is decreased, the driving frequency
`can be Smoothly returned to the resonance frequency.
`0034). According to the present invention (claim 11), the
`motor driving apparatus according to claim 1 further
`includes a driving frequency determining unit for determin
`ing a driving frequency of the linear Vibration motor; a target
`output determining unit for determining a target output as a
`motor output required of the linear Vibration motor; an
`output detection unit for detecting the motor output of the
`linear Vibration motor; a driving Voltage determining unit for
`determining a target Voltage value of the driving Voltage of
`the linear vibration motor So that a difference between the
`detected motor output and the determined target output
`becomes Zero; and a driving Voltage detection unit for
`detecting an actual Voltage Value of the driving Voltage of
`the linear Vibration motor; and the driving frequency deter
`mining unit Sets the driving frequency at a resonance fre
`quency which brings a Spring vibration System including the
`mover into a resonance State when the detected actual
`Voltage value does not exceed a reference value that is
`determined on the basis of the voltage value of a DC voltage
`Supplied to the motor driver, and Sets the driving frequency
`at a frequency higher than the resonance frequency when the
`detected actual Voltage value exceeds the reference value;
`and the motor driver controls the motor output and the Stroke
`of the mover by adjusting the frequency and Voltage value
`of the AC voltage Supplied to the linear Vibration motor So
`that the Voltage value of the AC voltage becomes equal to
`the target Voltage value determined by the driving Voltage
`determining unit, and the frequency of the AC voltage
`becomes equal to the driving frequency determined by the
`driving frequency determining unit. Therefore, the linear
`vibration motor can be efficiently driven even in a high
`output region, without being restricted by the Voltage level
`of the power Supply.
`0035) To be specific, even when the actual motor output
`is not equal to the required motor output, the linear Vibration
`motor can be efficiently driven at the resonance frequency
`until the actual motor output reaches the maximum output at
`which driving of the linear vibration motor at the resonance
`frequency is restricted by the Voltage level of the power
`Supply. Further, in a high output region where the actual
`motor output of the linear vibration motor that is driven at
`the resonance frequency exceeds the maximum output, the
`linear Vibration motor can be driven at a frequency higher
`than the resonance frequency, without Significantly reducing
`the driving frequency. Moreover, in the high output region,
`the driving frequency is Set at a frequency closest to the
`resonance frequency, at which the required motor output can
`be generated, whereby the driving frequency can be
`
`Smoothly returned to the resonance frequency when the
`required motor output is decreased.
`0036) According to the present invention (claim 12),
`there is provided an air conditioner equipped with a com
`preSSor which has a cylinder and a piston, and compresses
`a fluid in the cylinder by a reciprocating motion of the
`piston, and the air conditioner includes a linear Vibration
`motor for making the piston reciprocate, having a Stator and
`a mover, the mover being Supported by a Spring So as to form
`a Spring vibration System including the mover; and a motor
`driving unit for driving the linear vibration motor, which
`motor driving unit is a motor driving apparatus as defined in
`any of claims 1 to 11. Therefore, friction loss can be reduced
`as compared with a conventional rotation-type motor, and
`further, Sealability of the refrigerant between the high
`preSSure Side and the low-pressure Side is increased,
`whereby efficiency of the compressor is enhanced. More
`over, Since friction loSS is reduced, the amount of lubricating
`oil that is indispensable in the rotation-type motor can be
`Significantly reduced. Thereby, recyclability is enhanced,
`and the amount of refrigerant to be filled in the compressor
`is reduced because the amount of refrigerant that dissolves
`into the oil is reduced, resulting in a contribution to conser
`Vation of global environment. Further, Since performance of
`the linear compressor is controlled by the driving frequency,
`the linear compressor can be driven at maximum perfor
`mance without being restricted by the construction, whereby
`design that provides maximum efficiency at rated perfor
`mance can be carried out. As a result, the air conditioner
`using the linear compressor can be reduced in size and
`increased in efficiency.
`0037 According to the present invention (claim 13),
`there is provided a refrigerator equipped with a compressor
`which has a cylinder and a piston, and compresses a fluid in
`the cylinder by a reciprocating motion of the piston, and the
`refrigerator includes a linear Vibration motor for making the
`piston reciprocate, having a Stator and a mover, the mover
`being Supported by a Spring So as to form a Spring vibration
`System including the mover; and a motor driving unit for
`driving the line
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