JP2012148223A - Vibration generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a biased acceleration which is an uneven acceleration by a simple structure in a vibration generator.SOLUTION: The vibration generator includes: a stator having a coil; a needle having a permanent magnet; an elastic body which couples the stator and the needle to make the needle be able to vibrate by using the generation magnetic field of the coil corresponding to the input current to the needle and the magnetic action with the permanent magnet; and a voltage input part in which the pulse voltage corresponding to the proper period of the needle (a period of the damped vibration of the needle in the shut down period of voltage input to the coil ) is input to the coil. For instance, the pulse voltage which is a pulse voltage having a voltage polarity to make the needle face the opposite direction of the moving direction of the needle, and has a pulse width of less than 25% of a proper period is input to the coil in the timing that the phase of the speed signal of the sinusoid in the needle becomes 270°.

Description

  The present invention relates to a vibration generator that generates vibration.

  In recent years, a vibration generating device is often incorporated in a mobile phone or a game device, and specific information (incoming call notification or event occurrence) can be transmitted to a user by vibration generated by the vibration generating device. In a general vibration generator, a stator having a coil and a mover having a permanent magnet are coupled via an elastic body, and a sinusoidal voltage and current are input to the coil. Using the oscillating magnetic field generated by this input, the mover is vibrated in a one-dimensional direction. When a one-dimensional axis is divided into positive and negative with respect to the center of vibration, the acceleration of the mover is usually uniform between the positive and negative directions.

  On the other hand, acceleration that is not uniform between the positive and negative directions is called partial acceleration. If the partial acceleration is appropriately generated, the user can perceive a so-called force sense. For example, by generating a partial acceleration such that the positive acceleration is larger than the negative acceleration, it is possible to bring about an effect of directing the user's attention in the positive direction.

  In view of this, a special structure suitable for generating partial acceleration is disclosed in Patent Document 1 below.

  Patent Document 2 below shows a method of inputting a pulsed voltage to a vibration actuator.

Japanese Patent No. 4551448 Special table 2009-525175

  However, in the method of Patent Document 1, it is necessary to adopt a special structure specialized for the generation of the partial acceleration in order to generate the partial acceleration, and the structure of the vibration generator becomes complicated. In the method disclosed in Patent Document 2, uniform acceleration is generated (no partial acceleration is generated).

  Accordingly, an object of the present invention is to provide a vibration generator that can generate a partial acceleration with a simple structure.

  The vibration generator according to the present invention uses the magnetic action of a stator having a coil, a mover having a permanent magnet, a magnetic field generated by the coil according to an input current to the coil, and the permanent magnet. In a vibration generating device including the stator and an elastic body that connects the mover so that the mover can vibrate, a voltage input unit that inputs a pulse voltage corresponding to the natural period of the mover to the coil Is further provided.

  Thereby, it is possible to generate a partial acceleration with a simple structure and present a force sense to the user. The adoption of a simple structure contributes to reducing the size and cost of the vibration generator. Moreover, it is possible to generate normal vibration and partial acceleration with a common structure.

  Specifically, for example, during the vibration of the mover in the natural period, at the timing when the absolute value of the speed of the mover is maximized, the voltage input unit is in a direction opposite to the moving direction of the mover. A voltage having a voltage polarity for guiding the mover is input to the coil as the pulse voltage, or during the vibration of the mover in the natural period, the moving direction of the mover is changed from the first direction to the first direction. At the timing of switching to the second direction, which is the opposite direction of one direction, the voltage input unit inputs a voltage having a voltage polarity that guides the mover in the second direction to the coil as the pulse voltage.

  More specifically, for example, the pulse voltage has a pulse width of less than 25% of the natural period.

  Further, for example, the pulse voltage includes a first pulse voltage and a second pulse voltage that is input to the coil after the first pulse voltage, and the voltage input unit includes the first pulse for the coil. A delay time of the input timing of the second pulse voltage with respect to the coil, as viewed from the voltage input timing, is set according to the natural period.

  More specifically, for example, the voltage input unit sets the delay time so that the damping vibration of the mover generated by the input of the first pulse voltage is suppressed by the input of the second pulse voltage. Set according to the cycle.

  This makes it possible to obtain an effect of increasing the partial acceleration.

  More specifically, for example, the delay time has a length of 50% of the natural period, and each of the first and second pulse voltages has a pulse width less than 50% of the natural period. Have.

  Here, the numerical value “50%” should be interpreted as a numerical concept having a certain range.

  Further, for example, the voltage input unit repeatedly executes an operation of inputting the pulse voltage to the coil a plurality of times at a predetermined cycle.

  Thereby, it becomes possible to make a user perceive a force sense with an appropriate intensity.

  Further, for example, the stator further includes a magnetic body, and the natural period includes a magnetic attraction force between the permanent magnet and the magnetic body and a mechanical thrust of the elastic body when voltage input to the coil is stopped. The period of the damped oscillation of the mover generated by

  According to the present invention, it is possible to provide a vibration generator capable of generating a partial acceleration with a simple structure.

1 is an external perspective view of a vibrating device according to an embodiment of the present invention. It is an external appearance perspective view when dividing the vibration device of FIG. 1 into two. It is sectional drawing of the vibration device of FIG. It is an exploded view of the vibration device of FIG. FIG. 2 is an external perspective view (a) and (b) of a central yoke and a back yoke forming a stator yoke provided in the vibration device of FIG. 1, and a Z sectional view (c) of the central yoke. It is a figure which shows the coupling | bonding method of the center yoke around which the coil was wound, and two back yokes. It is sectional drawing along the X-axis of the permanent magnet provided in the vibration device of FIG. It is the figure which showed a mode that a voltage input part was connected to the vibration device of FIG. It is a figure for demonstrating the vibration operation | movement in the vibration device of FIG. It is sectional drawing which shows the 1st deformation structure of the vibration device which concerns on embodiment of this invention. It is sectional drawing which shows the 2nd deformation structure of the vibration device which concerns on embodiment of this invention. It is a figure for demonstrating the input conditions of the pulse voltage with respect to a coil. It is a figure which shows the vibration device model which concerns on embodiment of this invention. It is a figure which shows the result of the 1st simulation which concerns on embodiment of this invention. It is a figure which shows the result of the 1st simulation which concerns on embodiment of this invention. It is a figure which shows the signal waveform of the pulse voltage input periodically, and the signal waveform of speed and acceleration. It is a figure which shows the result of the 2nd simulation which concerns on embodiment of this invention. It is a figure which shows the result of the 3rd simulation which concerns on embodiment of this invention. It is a figure which shows the result of the 4th simulation which concerns on embodiment of this invention. It is a figure for demonstrating the damped vibration generate | occur | produced after a pulse voltage input. It is a figure for demonstrating the suppression method of a damped vibration. It is a figure for demonstrating the input conditions of the pulse voltage with respect to a coil. It is a figure which shows the result of the 5th simulation which concerns on embodiment of this invention. It is a figure which shows the result of the 5th simulation which concerns on embodiment of this invention. It is a figure which shows the result of the 5th simulation which concerns on embodiment of this invention. It is a figure which shows the result of the 6th simulation which concerns on embodiment of this invention. It is a figure which shows the result of the 6th simulation which concerns on embodiment of this invention. It is a figure which shows the result of the 6th simulation which concerns on embodiment of this invention. It is the figure which put together the result of the 6th simulation which concerns on embodiment of this invention. It is a figure which shows the result of the 1st experiment which concerns on embodiment of this invention. It is a figure which shows the result of the 2nd experiment which concerns on embodiment of this invention. It is a figure which shows the result of the 2nd experiment which concerns on embodiment of this invention. 1 is a schematic circuit block diagram of a vibration generator according to an embodiment of the present invention. It is a figure which shows the signal waveform of the acceleration which concerns on 3rd Example of this invention. It is a figure which shows the signal waveform of the acceleration which concerns on 3rd Example of this invention. It is a figure for demonstrating the measuring method of a natural period. It is a figure which shows the apparatus incorporating a vibration device.

  Hereinafter, an example of an embodiment of the present invention will be specifically described with reference to the drawings. In each of the drawings to be referred to, the same part is denoted by the same reference numeral, and redundant description regarding the same part is omitted in principle.

  FIG. 1 is an external perspective view of a vibrating device 1 according to an embodiment of the present invention. The vibration device 1 has a cylindrical outer shape with a relatively low height like a button battery. FIG. 2 shows an external perspective view of one member (half of the vibration device 1) obtained by cutting the vibration device 1 into two along the central axis of the cylinder. FIG. 3 shows a plan view of one of the members as viewed from the side, that is, a cross-sectional view of the vibration device 1 having a cross section taken along the central axis. FIG. 4 is an exploded view of the constituent members of the vibration device 1. The vibration device 1 can be mounted on any electronic device or an accessory of any electronic device. The electronic device includes, for example, a portable device such as a mobile phone and a portable game device, and a remote controller in a television receiver and a game device (however, the remote controller can be regarded as an accessory of the electronic device). is there).

  The vibration device 1 includes a cylindrical case 10 having a cavity therein, a stator yoke 20 formed of a magnetic material, a coil 21 wound around the stator yoke 20, and a permanent magnet 30 having a cylindrical shape. A cylindrical weight body 31 provided on the outer peripheral side of the permanent magnet 30 and spring materials 41 and 42 which are elastic bodies are provided. As shown in FIG. 4, the case 10 is formed by joining a disk-shaped case member 11 and a cup-shaped case member 12. For convenience of illustration, the coil 21 is not shown in FIG. 2, and the coil 21 and the spring materials 41 and 42 are not shown in FIG.

  The stator of the vibration device 1 includes a stator yoke 20 and a coil 21, and the mover of the vibration device 1 includes a permanent magnet 30 and a weight body 31. The stator and the movable element and the spring materials 41 and 42 are accommodated inside the case 10. While fixing the stator to the case 10, the vibrating device 1 is formed by arranging the mover so as to vibrate in the case 10 using the spring materials 41 and 42.

  The central axis of the coil 21 is defined as the Z axis. 3 corresponds to a cross-sectional view of the vibration device 1 having a cross section taken along a plane along the Z axis. The vibration direction of the mover is parallel to the Z axis. Hereinafter, a cross section along the Z axis is referred to as a Z cross section, and a cross section with the Z cross section as a cross section is referred to as a Z cross section. In the Z sectional view, an axis orthogonal to the Z axis is defined as the X axis. A cross section along the X axis is referred to as an X cross section, and a cross sectional view taken along the X cross section is referred to as an X cross sectional view. The X axis and the Z axis intersect at an origin O that coincides with the center point of the stator yoke 20. Further, a two-dimensional orthogonal coordinate plane having the X axis and the Z axis as coordinate axes is referred to as an XZ coordinate plane.

  It can be said that the stator yoke 20, the permanent magnet 30, and the weight body 31 arranged in the case 10 are all rotating bodies having the Z axis as a rotation axis. In the XZ coordinate plane, the stator yoke 20 disposed in the case 10 has a line-symmetric structure with respect to each of the Z axis and the X axis. In the XZ coordinate plane, the permanent magnet 30 and the weight body 31 have a line-symmetric structure with respect to the Z-axis and also have a line-symmetric structure with respect to the X-axis when the movement of the mover is stopped. ing.

  FIGS. 5A and 5B are external perspective views of the central yoke 25 and the back yoke 26 that are constituent members of the stator yoke 20, and FIG. 5C is a Z cross-sectional view of the central yoke 25. . FIG. 6 is a view showing a method of coupling the central yoke 25 around which the coil 21 is wound and the two back yokes 26.

  The central yoke 25 is a columnar yoke (rod-shaped yoke), and the coil 21 is wound along the outer peripheral surface of the central yoke 25. The central axis of the cylinder which is the outer shape of the central yoke 25 coincides with the Z axis which is the central axis of the coil 21. The back yoke 26 is a cylindrical yoke having a bottom surface of a magnetic material on only one of the upper surface and the lower surface, and has a cup-shaped outer shape. The inner peripheral radius of the back yoke 26 is larger than the outer peripheral radius of the central yoke 25. Projections are present on both end faces of the column of the central yoke 25 (see FIG. 5C), and a hole is formed in the center of the bottom surface of the back yoke 26. As shown in FIG. 6, after winding the coil 21 around the central yoke 25, the protrusions on the upper surface and the lower surface of the central yoke 25 are fitted into the holes of the first and second back yokes 26, thereby And the second back yoke 26 is coupled. Thereby, the stator yoke 20 around which the coil 21 is wound is formed.

  As described above, each of the permanent magnet 30 and the weight body 31 has a cylindrical (ring-shaped) outer shape with the Z axis as the central axis. Therefore, as shown in FIG. 7, the permanent magnet 30 draws a ring-shaped figure having an inner periphery and an outer periphery having a larger radius than the inner periphery in the X sectional view. The same applies to the weight body 31. The mover is formed by coupling the permanent magnet 30 and the weight body 31 so that the outer peripheral surface of the permanent magnet 30 and the inner peripheral surface of the weight body 31 are in contact with each other. The weight body 31 is a weight for setting the mass of the mover to a desired mass. The central yoke 25 and the back yoke 26 are made of a magnetic material. The relative permeability of the permanent magnet 30 has a value close to 1 (for example, 1.1), while the relative permeability of the magnetic material forming the central yoke 25 and the back yoke 26 has a sufficiently large value (for example, several hundreds). ~ Tens of thousands). The relative permeability of the weight body 31 is arbitrary. In this specification, a magnetic body and a magnetic material are synonymous.

  In this embodiment, as shown in FIG. 7, it is assumed that the inner peripheral side of the permanent magnet 30 is an N pole and the outer peripheral side of the permanent magnet 30 is an S pole (of course, it is possible to reverse them). Therefore, the inner peripheral surface and the outer peripheral surface of the permanent magnet 30 are an N pole surface and an S pole surface, respectively, and the N pole surface of the permanent magnet 30 is opposed to the outer peripheral surface of the coil 21 (see FIG. 3 and the like).

  One end of the spring material 41 is fixed to the upper inner surface of the case 10 (the inner surface of the case member 12) so that the Z-axis direction is the extension direction, and the other end is coupled to the upper surface of the mover. . One end of the spring material 42 is fixed to the inner surface (case member 11) on the lower side of the case 10 so that the Z-axis direction is the extension direction, and the other end is coupled to the lower surface of the mover. Therefore, if a force that moves the mover upward is applied, the spring material 41 contracts in the Z-axis direction while the spring material 42 extends, and if a force that moves the mover downward is applied, the force moves in the Z-axis direction. While the spring material 41 extends, the spring material 42 contracts. Here, the upward direction corresponds to the positive direction of the Z axis, and the downward direction corresponds to the negative direction of the Z axis.

  As shown in FIG. 8, the voltage input unit 2 is connected to the vibration device 1. Although not shown in each drawing including FIG. 1 and FIG. 6, a pair of lead wires LL electrically connected to both ends of the coil 21 are passed through holes provided in the stator yoke 20 and the case 10. , Pulled out of the case 10. The voltage input unit 2 can apply a voltage having an arbitrary signal waveform to the coil 21 via the pair of lead wires LL. For example, when an alternating voltage is applied to the coil 21, an alternating current flows through the coil 21, and a magnetic field corresponding to the alternating current appears in the stator yoke 20. In the present specification, the application of voltage to the coil 21 is also expressed as voltage input. The voltage input unit 2 can also be called a voltage application unit or a voltage supply unit that applies or supplies a voltage to the coil 21, and can also be called a current input unit or a current supply unit that inputs or supplies a current to the coil 21. .

  When no current is passed through the coil 21 and the vibration of the mover is stopped, the thrust (hereinafter referred to as mechanical thrust) by the spring members 41 and 42 is balanced, and the center of the mover in the Z-axis direction is X Located on the axis. A magnetic field is generated by passing an electric current through the coil 21, thereby generating a magnetic thrust that vibrates the mover in the Z-axis direction (hereinafter referred to as a magnetic thrust), and the mover moves in the Z-axis according to the magnetic thrust and the mechanical thrust. Vibrate in the direction. The magnetic thrust is a thrust generated by a magnetic action between a magnetic field generated by passing a current through the coil 21 and the permanent magnet 30.

  When a current in the first direction is passed through the coil 21, as shown in FIG. 9A, the upper and lower sides of the stator yoke 20 become the S pole and the N pole, respectively, and the N pole of the permanent magnet 30 and the stator yoke 20 lower magnetic poles (N poles) repel each other, while the N poles of the permanent magnet 30 and the upper magnetic poles (S poles) of the stator yoke 20 attract each other. Magnetic thrust that is directed to the positive side is generated. On the other hand, when a current in the second direction opposite to the first direction is passed through the coil 21, the upper and lower sides of the stator yoke 20 become the N pole and the S pole, respectively, as shown in FIG. Since the N pole of the magnet 30 and the upper magnetic pole (N pole) of the stator yoke 20 repel each other, the N pole of the permanent magnet 30 and the lower magnetic pole (S pole) of the stator yoke 20 attract each other. A magnetic thrust is generated that moves the mover downward (the negative side of the Z axis).

  Hereinafter, the voltage input from the voltage input unit 2 to the coil 21 is also simply referred to as a coil voltage. Also, the polarity of the coil voltage for flowing the current in the first direction through the coil 21 (that is, for guiding the mover upward) is positive, and the current in the second direction is flowed through the coil 21 It is assumed that the polarity of the coil voltage (ie, for guiding the mover downward) is negative. Therefore, for example, in a state where the vibration of the mover is stopped, if a positive coil voltage is input to the coil 21, the mover moves upward, and conversely, if a negative coil voltage is input to the coil 21, the mover Moves down.

  Since the stator is fixed to the case 10 and each end of the spring materials 41 and 42 is also fixed to the case 10, the spring materials 41 and 42 are supplied with the input current to the coil 21 (that is, the coil voltage). The stator and the mover via the case 10 so that the mover can vibrate in the Z-axis direction using the magnetic action of the magnetic field generated by the coil 21 and the permanent magnet 30 according to the current flowing in the coil 21 accordingly. It can be said that it is an elastic body connecting the two. Alternatively, it can be considered that the case 10 itself is also included in the constituent members of the stator. Further, the stator and the mover may be directly connected by an elastic body without the case 10 so that the mover can vibrate in the Z-axis direction.

  The internal structure of the vibration device 1 described above is merely an example, and can be variously modified. As an example, FIGS. 10 and 11 show Z cross-sectional views of the vibration device 1 according to the first and second modified structures. For example, as shown in FIG. 10, a mover yoke 32 may be provided on the inner peripheral side of the permanent magnet 30 as a component of the mover. The mover yoke 32 is a magnetic body having a cylindrical outer shape centered on the Z axis. In the first modified structure, the mover yoke 32 and the permanent magnet 30 are joined so that the outer peripheral surface of the mover yoke 32 and the inner peripheral surface of the permanent magnet 30 are in contact with each other. Further, for example, as shown in FIG. 11, an H-shaped stator yoke 20 a may be used instead of the stator yoke 20. In this case, the coil 21 is wound around the groove portion of the stator yoke 20a. Although the mover yoke 32 is provided in the second modified structure shown in FIG. 11, the mover yoke 32 may be deleted from the second modified structure.

  The voltage input unit 2 can input a coil voltage having a sinusoidal signal waveform to the coil 21. When a coil voltage having a sinusoidal signal waveform is input to the coil 21, a sinusoidal alternating current flows through the coil 21, and uniform acceleration is generated in the vibration device 1 between the positive and negative directions of the Z axis. On the other hand, in this embodiment, acceleration that is not uniform between the positive and negative directions of the Z-axis is referred to as partial acceleration.

  In the present embodiment, a pulse voltage (in other words, a rectangular wave voltage) is input to the coil 21 in order to realize the partial acceleration. Hereinafter, the pulsed coil voltage is referred to as a pulse voltage. Inputting the pulse voltage to the coil 21 is simply expressed as inputting the pulse voltage. As shown in FIG. 12, the pulse voltage is a voltage having a rectangular waveform. The voltage input unit 2 can periodically input a pulse voltage to the coil 21. The period of the coil voltage signal when the pulse voltage is periodically input to the coil 21 is called a pulse period and is represented by the symbol PP. The coil voltage signal is a voltage signal representing a coil voltage. The voltage value of the pulse voltage (that is, the magnitude of the pulse voltage) is represented by the symbol PV, and the pulse width in the pulse voltage is represented by the symbol PW. When only one pulse voltage is input in one pulse period, the coil voltage signal has a voltage value PV by the pulse width PW in the one pulse period, and the voltage value is zero during the remaining period (PP-PW). have. The voltage value PV has a positive or negative value (unit is volts). In the following description including FIG. 12, it is assumed that the voltage value PV is mainly positive.

  A number of simulations were conducted to verify the occurrence of partial acceleration while varying the input conditions of the pulse voltage. In each simulation, a vibration device model including a mover 101, a stator 102, and a spring 103 shown in FIG. 13 was used. In each simulation, it is assumed that a coil voltage is input to the coil 21 in the stator 102. The mover 101 and the stator 102 are models of the mover and the stator of the vibration device 1, respectively. The mover 101 and the stator 102 are the mover and the stator of the vibration device 1, respectively. You may think that there is. However, when another object is coupled to the vibration device 1, such as when the vibration device 1 is incorporated in another object (for example, a mobile phone), the other object is also the stator 102. Included in the component.

The vibration device model in FIG. 13 assumes a motion system in which each of the mover 101 and the stator 102 can move in the Z-axis direction. The spring 103 that contributes to the vibration of the mover 101 and the stator 102 is a combination of a mechanical spring and a magnetic spring. The mechanical spring is formed by mechanical spring materials 41 and 42, and the mechanical thrust by the spring materials 41 and 42 causes the mover 101 and the stator 102 to vibrate in the Z-axis direction. The magnetic spring is a spring based on the force that the permanent magnet 30 attracts the stator yoke 20 when the voltage input to the coil 21 is stopped (that is, the magnetic attractive force between the permanent magnet 30 and the stator yoke 20). This is a spring by the force that the permanent magnet 30 attracts the stator yoke 20 when no current flows through the coil 21 (that is, the magnetic attraction force between the permanent magnet 30 and the stator yoke 20). The magnetic spring also contributes to the vibration of the mover 101 and the stator 102 along the Z-axis direction. The masses of the mover 101 and the stator 102 are represented by m ₁ and m ₂ , respectively, and the spring constants of the mechanical spring and the magnetic spring are represented by K _m and _Ke, respectively. Then, the vibration frequency of the mover 101 and the stator 102 based on the spring 103 coincides with the natural frequency ω ₀ of the following formula (1). ω ₀ is an angular frequency. Note that when m ₁ << m ₂ , Equation (1) is approximated to Equation (2).

  The force of the spring 103 is a combination of a mechanical thrust by a mechanical spring and a magnetic attractive force by a magnetic spring. The vibration of the mover 101 and the stator 102 based only on the force of the spring 103 is a damped vibration, and the period of the damped vibration coincides with the natural period T corresponding to the characteristics of the mover 101, the stator 102 and the spring 103. . The natural period T is expressed by Equation (3). ζ is a damping coefficient determined by the structure of the vibration device 1 (1> ζ> 0), and π is a circumference. The natural period T is a period of the damped vibration of the movable element 101 (for example, the damped vibration of the speed or acceleration of the movable element 101) generated by the force of the spring 103 when the voltage input to the coil 21 is stopped. This is the period of the damped vibration of the stator 102 (for example, the damped vibration of the speed or acceleration of the stator 102).

  In the following description of each simulation, unless otherwise stated, the speed refers to the speed of the mover 101 and the acceleration refers to the acceleration of the stator 102 (the same applies to first to third embodiments described later). Further, the polarity of the speed and acceleration of the movement in the positive direction of the Z axis is defined as positive, and the polarity of the speed and acceleration of the movement in the negative direction of the Z axis is defined as negative. A signal representing the speed is called a speed signal, and a signal representing the acceleration is called an acceleration signal. In each of the following simulations, the natural period T was set to 6.4 milliseconds.

[First simulation]
The first simulation will be described. Reference is made to FIG. In the first simulation and second to fourth simulations to be described later, it is assumed that only one pulse voltage is input to the coil 21 in one pulse period, as shown in FIG. In the first simulation,
The pulse width PW is fixed at 5% of the natural period T (ie, PW = T × 0.05), and
The voltage value PV of the pulse voltage was fixed at 5 volts.

In the first simulation and the second to fourth simulations described later, in a state where the velocity and acceleration are oscillating in a damped manner (that is, in a state where the movable element 101 and the stator 102 are oscillating in a damped manner), a pulse is _generated at the timing tIN. A voltage was input to the coil 21 and the signal waveforms of velocity and acceleration after inputting the pulse voltage were examined. Inputting a pulse voltage to the coil 21 at a certain timing means that a rectangular wave voltage having a voltage value PW corresponding to the pulse width PW is input to the coil 21 from that timing.

FIG. 14 shows an example of a signal waveform obtained in the first simulation. Before the timing t _IN, the velocity signal is changing at the natural period T of 6.4 millisecond, the signal waveform of the speed signal is a sine wave. The vibration of the movable element 101 and the stator 102 at time t _IN Previously, those generated by previously entered time t _IN sinusoidal or pulsed coil voltage to the coil 21.

The phase of the speed signal with respect to the time point when the value of the speed signal switches from negative to positive is represented by phase α. In the graph of FIG. 14 and other graphs described later, the line ZR is a reference line representing zero in speed or acceleration. 14, curve 301, curve 302 and line 303, respectively, in the case where the phase α is set to a time period of 270 ° in timing _{t IN,} speed, represents the signal waveform of the acceleration and the coil voltage. In the graph of FIG. 14, the horizontal axis corresponds to time, and the vertical axis corresponds to speed, acceleration, or voltage. The input pulse voltage at timing t _IN, it is understood that the polarization acceleration positive acceleration and negative acceleration becomes unevenly occurs. The phase α of the speed signal at the timing (including t _IN ) when the pulse voltage is input to the coil 21 is referred to as the input phase α.

In the first simulation, the occurrence of partial acceleration was verified by changing the input phase α in various ways. FIG. 15 shows the verification result. In the graph of FIG. 15, the horizontal axis corresponds to the input phase α at the timing t _IN (that is, the phase shift of the pulse voltage with respect to the phase of the speed signal), and the vertical axis corresponds to the acceleration. Of acceleration values obtained after timing t _IN, (in the curve 302 of FIG. 14, the acceleration at point 311) the first minimum value having a negative value is referred to as the minimum acceleration, the first local maximum having a positive value The value (acceleration at the point 312 in the curve 302 in FIG. 14) is called the maximum acceleration.

15, curve 321 represents the relationship between the phase α and a maximum acceleration at the timing t _IN, curve 322 represents the relationship between the phase α and the minimum acceleration at time t _IN. A curve 323 represents the relationship between the phase α at the timing t _IN and the sum of the maximum acceleration and the minimum acceleration. The greater the absolute value of the sum of the maximum acceleration and the minimum acceleration, the greater the degree of inequality between positive and negative acceleration. Therefore, the absolute value of the sum of the maximum acceleration and the minimum acceleration can be interpreted as the magnitude of the partial acceleration. Hereinafter, the absolute value of the sum of the maximum acceleration and the minimum acceleration is also referred to as the amount of partial acceleration for convenience. As can be seen from the curve 323, the amount of partial acceleration is maximized when the input phase α is 270 °. Further, it was found that even when the input phase α is 0 °, the same amount of partial acceleration can be obtained as when the input phase α is 270 °.

By the way, when the pulse voltage is input to the coil 21 at a constant cycle so that only one pulse voltage is included in one pulse cycle, the input phase α is fixed at a certain phase corresponding to the pulse cycle. This phenomenon will be described with reference to FIG. In the graph of FIG. 16, the horizontal axis corresponds to time, and the vertical axis corresponds to speed and voltage. A curve 331 is a speed signal waveform when the pulse voltage is not input, and a curve 332 is a speed signal waveform when the pulse voltage is periodically input. A broken line 333 represents a signal waveform of the coil voltage for obtaining the speed signal of the curve 332. In the example of FIG. 16, a pulse voltage is input to the coil 21 at each of timings t _INA , t _INB, and t _INC .

Timing t _INA is timing when the phase α of the velocity signal corresponding to the curve 331 is 0 °. When a pulse voltage is input to the coil 21 at the timing t _INA , the speed rapidly rises to the maximum value, and then performs damped oscillation. At a timing t _INB when a predetermined time has elapsed from the timing t _INA, the phase α of the speed signal of the curve 332 becomes 0 °. When a pulse voltage is input to the coil 21 at this timing t _INB , the speed rapidly rises to the maximum value, and then damped oscillation is performed. At the timing t _INC when a predetermined time has elapsed from the timing t _INB, the phase α of the speed signal of the curve 332 becomes 0 °. When a pulse voltage is input to the coil 21 at this timing t _INC , the speed rapidly rises to the maximum value, and then damped oscillation is performed.

As described above, the pulse voltage in the example of FIG. 16 acts to discontinuously change the phase α of the speed signal from 0 ° to about 90 °. After the input of the i-th pulse voltage, the phase α of the speed signal becomes 0 ° at a certain timing. However, if the (i + 1) -th pulse voltage is input at that timing, then after the i-th pulse voltage is input Is obtained (i is an integer). That is, the waveform of the speed signal between the timings t _INB and t _INC is the same as the waveform of the speed signal between the timings t _INA and t _INB . Therefore, in the example of FIG. 16, the time interval between the timings t _INA and t _INB is the same as the time interval between the timings t _INB and t _INC . Thus, if a pulse voltage is input to the coil 21 at a certain fixed period, the pulse voltage is always input when the phase α is 0 °. The constant period depends on various parameters (the magnitude of the pulse voltage, the pulse width, the structural characteristics of the vibration device 1, etc.), but the constant period can be obtained in advance through experiments or the like. The same applies when a pulse voltage is input when the phase α is an angle other than 0 °.

  Therefore, the pulse period PP [j] can be obtained in advance through experiments or the like as the pulse period (j is a real number satisfying 0 ≦ j <360). The pulse period PP [j] is a pulse period for inputting a pulse voltage when the phase α of the speed signal is j °, and the voltage input unit 2 has a pulse voltage having a predetermined voltage value PV and a pulse width PW. Is input to the coil 21 at the pulse period PP [j], the pulse voltage is always input to the coil 21 when the phase α of the speed signal is j °.

[Second simulation]
The second simulation will be described. FIG. 17 shows the result of the second simulation. In the second simulation,
The input phase α is fixed at 270 °, and
After fixing the voltage value PV of the pulse voltage at 5 volts,
The pulse width PW dependence of the maximum acceleration, minimum acceleration, and partial acceleration was examined.

  In the graph of FIG. 17, the horizontal axis corresponds to the ratio (unit:%) of the pulse width PW to the natural period T, and the vertical axis corresponds to acceleration. In FIG. 17, a curve 351 represents the relationship between the ratio and the maximum acceleration, a curve 352 represents a relationship between the ratio and the minimum acceleration, and a curve 353 represents the ratio and the sum of the maximum acceleration and the minimum acceleration. Represents a relationship.

  As can be seen from FIG. 17, when the ratio of the pulse width PW to the natural period T (that is, PW / T) is set to less than 25%, a relatively large amount of partial acceleration is obtained, and when the ratio is set to 25% or more, The amount of partial acceleration was almost zero. Note that when the ratio was less than 25%, the minimum acceleration was substantially constant. Therefore, the voltage input unit 2 may input a pulse voltage with the ratio set to less than 25% to the coil 21, thereby generating a partial acceleration having a certain magnitude.

[Third simulation]
The third simulation will be described. FIG. 18 shows the result of the third simulation. In the third simulation,
The input phase α is fixed at 270 °, and
After fixing the pulse width PW at 5% of the natural period T (that is, PW = T × 0.05),
The voltage value PV dependency of the maximum acceleration, the minimum acceleration, and the amount of partial acceleration was examined.

  In the graph of FIG. 18, the horizontal axis corresponds to the voltage value PV (unit: volts) of the pulse voltage, and the vertical axis corresponds to the acceleration. In FIG. 18, a line 371 represents the relationship between the voltage value PV and the maximum acceleration, a line 372 represents the relationship between the voltage value PV and the minimum acceleration, and a line 373 represents the voltage value PV and the maximum acceleration and the minimum acceleration. Represents the relationship with the sum. As can be seen from FIG. 18, the amount of partial acceleration increases as the voltage value PV of the pulse voltage is increased.

[Fourth simulation]
The fourth simulation will be described. FIG. 19 shows the result of the fourth simulation. In the fourth simulation,
The input phase α is fixed at 270 °, and
After fixing the pulse width PW at 25% of the natural period T (that is, PW = T × 0.25),
The voltage value PV dependency of the maximum acceleration, the minimum acceleration, and the amount of partial acceleration was examined.

  In the graph of FIG. 19, the horizontal axis corresponds to the voltage value PV (unit: volts) of the pulse voltage, and the vertical axis corresponds to the acceleration. In FIG. 19, a line 391 represents the relationship between the voltage value PV and the maximum acceleration, a line 392 represents a relationship between the voltage value PV and the minimum acceleration, and a line 393 represents the voltage value PV, the maximum acceleration, and the minimum acceleration. Represents the relationship with the sum. As can be seen from FIG. 19, in the case where the pulse width is set to 25% of the natural period T, it is found that the partial acceleration hardly occurs regardless of the voltage value PV of the pulse voltage.

[Damping vibration after 1 pulse input]
Refer to FIG. Waveforms 401, 402, and 403 in FIG. 20 are each one of signal waveforms of velocity, acceleration, and coil voltage obtained in the first, second, third, or fourth simulation. When only one pulse voltage is input to the coil 21 in one pulse period as in the case of the pulse voltage assumed in the first to fourth simulations, a damped vibration of speed and acceleration is generated after the pulse voltage is input (however, as shown in the figure). Although not performed, when the pulse width PW is set to 100% of the natural period T, almost no damped vibration is generated). In FIG. 20, signal waveforms 401 and 402 within a broken line 404 represent velocity and acceleration damped oscillations. The damped vibration of the velocity corresponds to the damped vibration of the movable element 101. When the movable element 101 performs the damped vibration, the stator 102 also performs the damped vibration as a reaction.

  If the damped oscillation after the input of the pulse voltage can be stopped quickly, the partial acceleration can be increased by that amount (first merit). For example, if the speed can be abruptly returned to zero after the speed has taken an extreme value by the input of the pulse voltage, a large partial acceleration is generated by the reaction in which the speed is abruptly returned to zero as shown in FIG. Because. In FIG. 21, it is assumed that the second pulse voltage is input after a lapse of a predetermined time after the first pulse voltage is input, and the speed generated by the input of the first pulse voltage and The decay vibration of acceleration is suddenly stopped by the input of the second pulse voltage.

  In addition, although depending on the characteristics of the vibration device 1, it is often necessary to intermittently input a plurality of pulse voltages in order to make the user perceive vibration firmly. In this case, if the damped oscillation based on the (i-1) th pulse voltage input remains when the i-th pulse voltage is input, the i-th pulse voltage is considered in consideration of the phase of the speed signal. It may be necessary to determine the input timing of the pulse voltage. If a technique for quickly stopping the damped oscillation based on the (i-1) th pulse voltage input is applied, a desired timing (for example, the user can select the vibration device without considering the phase of the speed signal). The i-th pulse voltage can be input at a timing at which the vibration of 1 is easily perceived (second merit).

  In order to enjoy such merits, it was verified in the fifth and sixth simulations described later whether or not the damped oscillation could be quickly stopped by inputting two pulse voltages in one pulse period.

  FIG. 22 shows signal waveforms of coil voltages in the fifth and sixth simulations. In the fifth and sixth simulations, the first pulse voltage and the second pulse voltage are input to the coil 21 within one pulse period. Within one pulse period, the second pulse voltage is input to the coil 21 after the delay time DL from the first pulse voltage. The voltage values PV of the first and second pulse voltages are the same, and the pulse widths PW of the first and second pulse voltages are also the same. The coil voltage at the timing when the first or second pulse voltage is not input to the coil 21 is zero.

[Fifth simulation]
The fifth simulation will be described. In the fifth simulation,
The pulse period PP is fixed at a certain fixed period, and
The voltage value PV of the pulse voltage is fixed at 5 volts, and
With the pulse width PW fixed at 10% of the natural period T (that is, PW = T × 0.10), a pulse voltage sequence composed of the first and second pulse voltages was periodically input to the coil 21. . At this time, the state of speed and acceleration was examined by variously changing the delay time DL.

  Nine graphs showing the results of the fifth simulation are shown in FIGS. 23A to 23C, 24A to 24C, and FIGS. 25A to 25C. In each of the nine graphs, the horizontal axis corresponds to time, and the vertical axis corresponds to speed, acceleration, or coil voltage. FIG. 23 (a), FIG. 23 (b), FIG. 23 (c), FIG. 24 (a), FIG. 24 (b), FIG. 24 (c), FIG. 25 (a), FIG. (C) shows the speed and acceleration when the delay time DL is set to 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% of the natural period T, respectively. And the signal waveform of coil voltage is shown. When i is 20, 30, 40, 50, 60, 70, 80, 90, or 100, the curve Vel_DL [i], the curve Acc_DL [i], and the polygonal line Vol_DL [i] each have a delay period DL with a natural period. The signal waveforms of speed, acceleration, and coil voltage when i% is set.

From the above nine graphs, the following can be understood.
When the delay time DL is 20%, 30%, 40%, 60%, 70%, 80%, 90% or 100% of the natural period T, the damped oscillation of velocity and acceleration based on the input of the first pulse voltage is On the contrary, the amplitude of the vibration of the speed and the acceleration may be increased by the input of the second pulse voltage without being suppressed by the input of the second pulse voltage.
On the other hand, when the delay time DL is 50% of the natural period T, the velocity and acceleration damped oscillation based on the input of the first pulse voltage is suppressed by the input of the second pulse voltage.

  Unlike the velocity and acceleration signal waveforms in FIG. 23A and the like, the velocity and acceleration signal waveforms in FIG. 24A have substantially the same speed and acceleration before the input of the pulse voltage 411 as the first pulse voltage. It is zero. This is because the speed and acceleration are sharply reduced to near zero by the second pulse voltage (pulse voltage input before one pulse period of the pulse voltage 412) in the pulse period before the pulse period including the pulse voltage 411. This is because.

[Sixth simulation]
The sixth simulation will be described. In the sixth simulation,
The pulse period PP is fixed at a certain fixed period, and
The voltage value PV of the pulse voltage is fixed at 5 volts, and
With the delay time DL fixed at 50% of the natural period T (that is, DL = T × 0.50), a pulse voltage string composed of the first and second pulse voltages is periodically input to the coil 21. . At this time, the state of speed and acceleration was examined by changing the pulse width PW variously.

  Nine graphs showing the results of the sixth simulation are shown in FIGS. 26A to 26C, FIGS. 27A to 27C, and FIGS. 28A to 28C. In each of the nine graphs, the horizontal axis corresponds to time, and the vertical axis corresponds to speed, acceleration, or voltage. 26 (a), 26 (b), 26 (c), 27 (a), 27 (b), 27 (c), 28 (a), 28 (b), 28 (C) shows the speed and acceleration when the pulse width PW is set to 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90% of the natural period T, respectively. And the signal waveform of coil voltage is shown. When i is 10, 20, 30, 40, 50, 60, 70, 80, or 90, the curve Vel_PW [i], the curve Acc_PW [i], and the polygonal line Vol_PW [i] each have a pulse width PW with a natural period. The signal waveforms of speed, acceleration, and coil voltage when i% is set.

  In the sixth simulation, since the delay time DL is 50% of the natural period T, when the pulse width PW is 50% of the natural period T, as shown in FIG. The end point coincides with the input start point of the second pulse voltage, and the first and second pulse voltages form one pulse voltage having a pulse width of (2 × PW). When the pulse width PW is larger than 50% of the natural period T, the second half of the first pulse voltage and the first half of the second pulse voltage overlap as shown in FIG. During the period in which the second pulse voltages overlap, a voltage having a voltage value of (2 × PV) is input to the coil 21.

  FIG. 29 summarizes the results of the sixth simulation. In the graph of FIG. 29, the horizontal axis corresponds to the ratio (unit:%) of the pulse width PW to the natural period T, and the vertical axis corresponds to acceleration. In FIG. 29, a line 451 represents the relationship between the ratio and the maximum acceleration, a line 452 represents a relationship between the ratio and the minimum acceleration, and a line 453 represents the ratio and the sum of the maximum acceleration and the minimum acceleration. Represents a relationship.

  As can be seen from FIG. 29, it was found that when the ratio of the pulse width PW to the natural period T (that is, PW / T) is set to less than 50% under the conditions of the sixth simulation, partial acceleration occurs.

[First experiment (1 pulse input)]
The first experiment will be described. In each of the above simulations, the state of the speed signal and the like was examined by numerical calculation. On the other hand, in the first experiment and the second experiment described later, a pulse voltage is actually input to the coil 21, and the voltage between both terminals of the coil 21 and the acceleration of the stator are measured by the voltage detection sensor and the acceleration sensor. Measured.

  FIGS. 30A and 30B show the measurement results of the first experiment. In the first experiment, as in the first to fourth simulations, the pulse voltage is repeatedly input to the coil 21 at a constant period so that only one pulse voltage is included in one pulse period (how much the input phase α is). The pulse voltage was repeatedly input to the coil 21 at a constant cycle without particularly worrying about whether or not. In the first experiment, the pulse PW was fixed to 8% of the natural period T, and the voltage value PV of the pulse voltage was fixed to 5 volts. A waveform 481 in FIG. 30A represents a coil voltage signal waveform in the first experiment, and a waveform 482 in FIG. 30B represents an acceleration signal waveform in the first experiment. In the first experiment, occurrence of partial acceleration was observed by the input of a pulse voltage.

  In the graph of FIG. 30A, the horizontal axis corresponds to time, and the vertical axis corresponds to the coil voltage (the same applies to FIGS. 31A and 32A described later). In the graph of FIG. 30B, the horizontal axis corresponds to time, and the vertical axis corresponds to acceleration (the same applies to FIGS. 31B and 32B described later). In the graph of FIG. 30A, unlike the graphs in the above-described simulations, the downward direction of the drawing corresponds to the positive direction of voltage (the same applies to FIGS. 31A and 32A described later). ).

[Second experiment (2-pulse input)]
FIGS. 31A and 31B and FIGS. 32A and 32B show the measurement results of the second experiment. In the second experiment, similar to the fifth and sixth simulations, the pulse voltage train composed of the first and second pulse voltages is repeatedly coiled at a constant period so that the first and second pulse voltages are included in one pulse period. 21. In the second experiment, the pulse PW was fixed to 42% of the natural period T, and the voltage value PV of the pulse voltage was fixed to 3 volts. Waveforms 491 and 493 in FIGS. 31A and 32A represent signal waveforms of the coil voltage in the second experiment, and waveforms 492 and 494 in FIGS. 31B and 32B are the second waveform. The acceleration signal waveform in the experiment is shown. However, when obtaining the waveforms 491 and 492, the delay time DL is set to 50% of the natural period T, and when obtaining the waveforms 492 and 494, the delay time DL is set to 60% of the natural period T. .

  As can be seen from the waveforms 491 to 494, when the delay time DL is set to 50% of the natural period T, the damped oscillation after the pulse voltage is input is suppressed, but the delay time DL is set to 60% of the natural period T. In this case, it can be seen that the damped oscillation after the pulse voltage input is not suppressed. Note that the observed waveforms 491 and 493 are not clean rectangular waveforms, but this is due to the influence of the induced voltage generated in the coil 21.

[Circuit block diagram]
FIG. 33 shows a schematic circuit block diagram of a vibration generator having a vibration device 1 and a voltage input unit 2 as a linear oscillatory actuator. The voltage input unit 2 in FIG. 33 includes a control circuit 3 having a CPU (Central Processing Unit), a D / A converter, and the like, and a driver 4. The control circuit 3 generates a digital signal having a voltage to be input to the coil 21 and converts the digital signal into an analog signal in a D / A converter. The driver 4 amplifies this analog signal and actually inputs the amplified analog signal to the coil 21 as a voltage signal. The driver 4 may be provided in the control circuit 3.

  The voltage input unit 2 can output to the coil 21 a voltage signal for causing the vibration device 1 to generate normal vibration (vibration due to acceleration symmetrical between positive and negative). That is, a sinusoidal voltage signal can be input to the coil 21. Apart from the sinusoidal voltage signal, the voltage input unit 2 can input a rectangular wave voltage signal for generating the partial acceleration to the coil 21.

  For this reason, in the vibration generator according to the present embodiment, the partial acceleration can be generated with a simple structure without requiring a dedicated structure for generating the partial acceleration, and a force sense can be presented to the user. Is possible. The adoption of a simple structure contributes to reducing the size and cost of the vibration generator. Moreover, normal vibration and partial acceleration can be generated with a common structure.

  Hereinafter, for convenience of explanation, a method of inputting only one pulse voltage to the coil 21 within one pulse period assumed in the first to fourth simulations is referred to as a one-pulse method, and is assumed in the fifth and sixth simulations. A method of inputting two pulse voltages to the coil 21 within one pulse period is called a two-pulse method.

[First embodiment]
First, a voltage input example in the one-pulse method will be described as a first embodiment. The voltage input unit 2 can actually input the arbitrary pulse voltage described in the above first to fourth simulations to the coil 21 of the vibration device 1.

  In the first simulation, it was found that a large partial acceleration can be obtained when the input phase α is set to 270 ° or 0 ° (see FIG. 15). In the first simulation, it is assumed that a positive pulse voltage is input to the coil 21, but when the phase α is 270 °, the positive pulse voltage is input to the coil 21 and the phase α is 90 °. It can be said that inputting a negative pulse voltage to the coil 21 is equivalent, and both produce the same partial acceleration, although the polarities are different. Similarly, inputting a positive pulse voltage to the coil 21 when the phase α is 0 ° is equivalent to inputting a negative pulse voltage to the coil 21 when the phase α is 180 °. No, the polarities are different, but both produce the same partial acceleration. Therefore, when it is desired to generate a larger partial acceleration, the voltage input unit 2 inputs a positive pulse voltage to the coil 21 when the phase α of the speed signal is 270 ° or 0 °, or the phase of the speed signal. It is desirable to input a negative pulse voltage to the coil 21 when α is 90 ° or 180 °. However, it is also possible to input a positive or negative pulse voltage to the coil 21 when the phase α of the speed signal is an arbitrary phase.

Note that the angle value specifically described with respect to the phase α (for example, 0 °, 90 °, 180 °, or 270 °) can be considered as a numerical concept having a certain width. That is, for example, when the phase α of the speed signal is j °, a positive pulse voltage is input to the coil 21 so that the phase α of the speed signal satisfies “j ° −Δ _A ≦ α ≦ j ° + Δ _A ”. It may be construed as including a method of inputting a positive pulse voltage to the coil 21 when satisfying. Here, delta _A is a positive small angle value (e.g., 5 °).

  In the first simulation, when the phase α of the speed signal is 270 °, the speed of the mover 101 takes a negative extreme value, and when the phase α of the speed signal is 90 °, the speed of the mover 101 is positive. Take extreme values. Accordingly, in the first simulation, the timing when the phase α becomes 270 ° or 90 ° is the timing when the absolute value of the velocity of the movable element 101 takes the maximum value (maximum value). The positive pulse voltage at the timing when the phase α is 270 ° functions as a pulse voltage that guides the mover 101 in the direction opposite to the moving direction of the mover 101 (forward direction). Similarly, the phase α is 90 °. The negative pulse voltage at the timing functions as a pulse voltage that guides the mover 101 in the direction opposite to the moving direction of the mover 101 (negative direction). On the other hand, in the first simulation, the timing when the phase α of the speed signal is 0 ° is the timing when the moving direction of the mover 101 switches from the negative direction of the Z axis to the positive direction, and the phase α of the speed signal is 180 °. Is a timing at which the moving direction of the mover 101 is switched from the positive direction of the Z axis to the negative direction.

  Further, it was found from the second simulation that in the one-pulse method, when the pulse width PW is 25% or more of the natural period T, almost no partial acceleration can be obtained (see FIG. 17). Therefore, it is desirable that the voltage input unit 2 sets the pulse width PW to be less than 25% of the natural period T when it is desired to generate a larger partial acceleration. Setting the pulse width PW to less than 25% of the natural period T can be applied to an arbitrary input phase α.

  Further, it was found from the third and fourth simulations that the amount of partial acceleration increases when the voltage value PV of the pulse voltage is increased in the one-pulse method (see FIGS. 18 and 19). Therefore, when it is desired to generate a larger partial acceleration, it is desirable that the voltage input unit 2 sets the voltage value PV of the pulse voltage as large as possible (the same applies to the two-pulse method). However, the upper limit or lower end of the mover composed of the permanent magnet 30 and the weight body 31 should have an upper limit for the voltage value PV so that the case 10 is not hit by the input of the pulse voltage (the same applies to the two-pulse method). ).

As described in the description of the first simulation, the pulse period PP [j] can be obtained in advance through experiments or the like. However, since the pulse period PP [j] depends on the pulse width PW and the voltage value PV, the pulse period PP [j] corresponding to the pulse width PW and voltage value PV of the pulse voltage actually input to the coil 21 is obtained. Like that. That is, for example, the pulse period PP [j] is obtained through experiments or the like while the pulse width PW and the voltage value PV are set to the pulse width PW _A and the voltage value PV _A , respectively, and the obtained pulse period PP [j] is controlled. The data is stored in a parameter storage unit (not shown) in the circuit 3. Thereafter, when a pulse voltage is input to the coil 21 with the pulse width PW and the voltage value PV set to the pulse width PW _A and the voltage value PV _A , respectively, the pulse period PP [j] stored in the parameter storage unit is used. Thus, it is only necessary to input a pulse voltage to the coil 21, whereby the pulse voltage can always be input to the coil 21 when the phase α of the speed signal is j °. The pulse period PP [j] to be obtained includes, for example, the pulse periods PP [0], PP [90], PP [180], and PP [270].

  In the one-pulse method, when the first pulse voltage is input to the coil 21, the mover 101 may be stopped or oscillating. When the first pulse voltage is input to the coil 21 when the mover 101 is stopped, the phase α cannot be defined for the speed signal in the first place, but the pulse voltage is periodically changed with the pulse period PP [j]. If input to the coil 21, the input phase α of the second and subsequent pulse voltages becomes a desired phase (270 °, etc.).

  After a sinusoidal coil voltage is input to the coil 21, the first pulse voltage can be input to the coil 21 during the damped oscillation corresponding to the input. In this case, the phase α of the current speed signal is estimated from the signal waveform of the sinusoidal coil voltage input in the past, and the input timing of the first pulse voltage is determined using the estimation result. Also good. According to this, the input phase α of the first pulse voltage can be matched with the desired phase (such as 270 °).

[Second Embodiment]
Next, a voltage input example in the two-pulse method will be described as a second embodiment. The voltage input unit 2 can actually input the arbitrary pulse voltage described in the above fifth and sixth simulations to the coil 21 of the vibration device 1.

  The voltage input unit 2 has a delay time so that the damped vibration of the mover 101 and the stator 102 generated by the input of the first pulse voltage to the coil 21 is suppressed by the input of the second pulse voltage to the coil 21. DL can be set according to the natural period T (see FIGS. 21 and 22). In order to satisfactorily realize the suppression, it is desirable to set the delay time DL to 50% of the natural period T, and it is desirable to set the pulse width PW to less than 50% of the natural period T (FIG. 24 ( a) and FIG. 29 etc.).

Note that the numerical value “50%” specifically describing the delay time DL can be considered to be a numerical concept having a certain range. That is, for example, the method of setting the delay time DL to 50% of the natural period T is within the range satisfying “T × (0.5−Δ _B ) ≦ DL ≦ T × (0.5 + Δ _B )”. It may be construed as including a method of setting a DL. Here, delta _B, a small positive value less than 50% (e.g., 5%).

[Third embodiment]
A third embodiment relating to an example of voltage input to the coil 21 will be described. The partial acceleration can be generated satisfactorily by inputting the pulse voltage as described in the first or second embodiment. When the partial acceleration occurs, the acceleration in the positive direction (the positive direction of the Z axis) and the acceleration in the negative direction (the negative direction of the Z axis) of the moving object are asymmetric in one cycle of the acceleration signal. The moving object is the mover 101 or the stator 102. By generating the partial acceleration, the user who has the vibration device 1 or the device incorporating the vibration device 1 in his / her hand can perceive a so-called force sense. For example, by generating a partial acceleration such that the positive acceleration is larger than the negative acceleration, it is possible to bring about an effect of directing the user's attention in the positive direction.

  The frequency at which humans can easily perceive force sense is about 10 Hz (hertz). Therefore, the voltage input part 2 is good to repeatedly perform operation which inputs a pulse voltage to the coil 21 with a period of 10 Hz (or a period of about 10 Hz).

  FIG. 34 shows an acceleration simulation result when a pulse voltage is input to the coil 21 at a cycle of 10 Hz. As shown in FIG. 34, the voltage input unit 2 can repeatedly input the pulse voltage in the one-pulse method to the coil 21 at a cycle of 10 Hz, and the input condition of the pulse voltage in the one-pulse method is that of the first embodiment. Can be applied. Instead of this, the voltage input unit 2 may repeatedly input the pulse voltage in the two-pulse method to the coil 21 at a cycle of 10 Hz. That is, the operation of inputting a pulse voltage sequence composed of the first and second pulse voltages to the coil 21 may be repeatedly executed at a cycle of 10 Hz. As the input condition of the pulse voltage in the two-pulse method, that of the second embodiment can be applied.

  However, only by inputting the pulse voltage for one period, the partial acceleration is generated only for a very short time, so the force sense perceived by the user is small. Therefore, as shown in FIG. 35, the voltage input unit 2 may repeatedly execute an operation of inputting the pulse voltage to the coil 21 continuously over a plurality of pulse periods at a predetermined period. For example, a period of 10 Hz (or a period of about 10 Hz) may be adopted. According to the method of FIG. 35, the generation period of the partial acceleration is longer than that of the method of FIG. 34, so that the user can easily perceive force sense.

  As shown in the example of FIG. 35, the voltage input unit 2 regards a continuous 6 pulse period (that is, 6 × PP) as a unit section, and inputs a pulse voltage to the coil 21 so that the unit section repeatedly visits at a period of 10 Hz. can do. In each unit section, a pulse voltage can be input to the coil 21 by a 1-pulse method or a 2-pulse method over a 6-pulse period (in the example of FIG. 35, the 2-pulse method is adopted). Therefore, when a pulse voltage is input by the one-pulse method, a total of six pulse voltages are input to the coil 21 in one unit section, and when a pulse voltage is input by the two-pulse method, the first pulse is input in one unit section. And six second pulse voltages are input to the coil 21. The number of pulse periods belonging to one unit section may be other than six.

  When the one-pulse method is adopted, that of the first embodiment can be applied as a pulse voltage input condition in each unit section. When the two-pulse method is adopted, that of the second embodiment can be applied as a pulse voltage input condition in each unit section.

Note that the numerical value of the period of “10 Hz” described in the third embodiment can be considered to be a numerical concept having a certain width. That is, for example, a method of repeatedly executing a certain operation at a cycle of 10 Hz is interpreted as including a method of repeatedly executing the operation at a cycle of (10−Δ _C ) Hz or more and (10 + Δ _C ) Hz or less. May be. Here, delta _C is a small positive value less than 10 (e.g., 1 or 2).

[Measurement method of natural period T]
A method for measuring the natural period T will be described. When measuring the natural period T, an acceleration sensor 121 for measuring acceleration is installed in the vicinity of the vibration device 1 as shown in FIG. Then, a voltage signal having a sine wave shape or a rectangular wave shape is output from the control circuit 3, and thereby a coil voltage having a sine wave shape or a rectangular wave shape is input to the coil 21. After a sine wave or rectangular wave coil voltage is input to the coil 21 for a certain period, the coil voltage input is stopped, and the acceleration of the damped vibration of the stator 102 generated after the stop is measured by the acceleration sensor 121. The natural period T can be obtained by observing the signal waveform of the acceleration measured by the acceleration sensor 121 using the oscilloscope 122. The control circuit 3 can determine the input condition of the pulse voltage to the coil 21 using the obtained natural period T. The cycle of acceleration in the stator 102 matches the cycle of speed and acceleration in the mover 101.

Further, as can be seen from the above formulas (1) and (3), the natural period T also depends on the mass m _{2 of the} stator 102. Therefore, the natural period T may be measured for each device in which the vibration device 1 is incorporated. That is, as shown in FIG. 37, after the vibration device 1 is actually incorporated into the device 123 in which the vibration device 1 is to be incorporated, a sine wave or rectangular wave coil voltage is input to the coil 21 for a certain period, The input of voltage may be stopped, and the acceleration of the damped vibration of the stator 102 generated after the stop may be measured by the acceleration sensor 121. When the vibration device 1 is incorporated in the device 123, the entire part excluding the mover 101 from the device 123 including the vibration device 1 functions as the stator 102. The natural period T can be obtained by observing the signal waveform of the acceleration measured by the acceleration sensor 121 using the oscilloscope 122. The control circuit 3 can determine the input condition of the pulse voltage to the coil 21 using the obtained natural period T.

  The embodiment of the present invention can be appropriately modified in various ways within the scope of the technical idea shown in the claims. The above embodiment is merely an example of the embodiment of the present invention, and the meaning of the term of the present invention or each constituent element is not limited to that described in the above embodiment.

DESCRIPTION OF SYMBOLS 1 Vibration device 2 Voltage input part 3 Control circuit 4 Driver 10 Case 20 Stator yoke 21 Coil 25 Central yoke 26 Back yoke 30 Permanent magnet 31 Weight body 32 Movable yoke 41, 42 Spring material 101 Movable element 102 Stator 103 Spring

Claims (8)

A stator having a coil;
A mover having a permanent magnet;
An elastic body that couples the stator and the mover so that the mover can vibrate using the magnetic action of the magnetic field generated by the coil and the permanent magnet according to the input current to the coil. In the vibration generator
The vibration generator further comprising a voltage input unit that inputs a pulse voltage corresponding to a natural period of the mover to the coil. During the vibration of the mover in the natural period, at the timing when the absolute value of the speed of the mover becomes maximum,
The voltage input unit inputs a voltage having a voltage polarity that guides the mover in a direction opposite to the moving direction of the mover to the coil as the pulse voltage, or
During the vibration of the mover in the natural period, at the timing when the moving direction of the mover is switched from the first direction to the second direction which is the opposite direction of the first direction,
2. The vibration generating device according to claim 1, wherein the voltage input unit inputs a voltage having a voltage polarity that guides the movable element in the second direction to the coil as the pulse voltage. The vibration generator according to claim 1, wherein the pulse voltage has a pulse width of less than 25% of the natural period. The pulse voltage includes a first pulse voltage and a second pulse voltage input to the coil after the first pulse voltage,
The voltage input unit sets a delay time of the input timing of the second pulse voltage to the coil, as viewed from the input timing of the first pulse voltage to the coil, according to the natural period. The vibration generator according to claim 1. The voltage input unit sets the delay time according to the natural period so that the damped oscillation of the mover generated by the input of the first pulse voltage is suppressed by the input of the second pulse voltage. The vibration generator according to claim 4. The delay time has a length of 50% of the natural period; and
6. The vibration generating device according to claim 4, wherein each of the first and second pulse voltages has a pulse width of less than 50% of the natural period. The vibration generating apparatus according to claim 1, wherein the voltage input unit repeatedly performs an operation of inputting the pulse voltage to the coil a plurality of times at a predetermined cycle. The stator further includes a magnetic body,
The natural period is a period of a damped vibration of the mover generated by a magnetic attractive force between the permanent magnet and the magnetic body and a mechanical thrust of the elastic body when voltage input to the coil is stopped. The vibration generator according to any one of claims 1 to 7, characterized in that: