JP2001340810A - Vibration generator and mobile telephone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration generator which is activated by always following up a mechanical resonance point. SOLUTION: This vibration generator 1 has a vibration generation part 2 consisting of a magnet 11 fixed loosely with a spring member 12 and an electromagnetic coil 13 and drives the electromagnetic coil 13 in the form of a square wave to obtain a vibrating force. In addition, the vibration generator 1 has a drive control part 10 which performs such a sequential control that the drive voltage of the electromagnetic coil 13 is detected at every specified time and the drive frequency of the coil 13 is heightened when an induced voltage wave-form of the drive voltage rises to the right and the drive frequency of the coil 13 is lowered when the wave-form rises to the left. Thus it is possible to shift the drive frequency of the coil 13 to the resonance frequency of the vibration generation part 2 and, consequently, enable the drive of the coil 13 to always follow up the mechanical resonance point to obtain a significant vibrating force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration generator suitable for use in portable telephones, game machines and the like.

[0002]

2. Description of the Related Art Conventionally, as a vibration generator of this type, a weight made of a metal having a high specific gravity is eccentrically mounted on the output shaft of a small motor, and the vibration of the weight moving with the rotation of the motor is used. Most of them have a structured structure. When such a vibration generating device is incorporated in a mobile phone, by generating vibration with a weight instead of generating a ringing sound, for example, it is possible to confirm reception without being known to others even in a crowd or during a conference In the case of a game machine, the vibration generating device is incorporated in the operation unit. For example, in a car racing game, a fighting game, or the like, the operation unit is appropriately vibrated according to the scene, thereby realizing a real presence for the operator. Can give a feeling. Therefore, it is necessary to generate high-amplitude and high-energy vibration in order to exert such a use effect more remarkably, and the appearance of such a high-efficiency vibration generator is desired.

[0003]

However, in the vibration generator having the above-mentioned structure, it is necessary to increase the eccentric weight and operating capacity of the weight to obtain a high amplitude and high energy vibration, and the drive motor is naturally used. Due to the increase in size and the weight of the high specific gravity metal being expensive, it has been an obstacle to miniaturization and price reduction of recent equipment.

In addition, since a DC motor is usually used as a drive source in a vibration generator, electromagnetic noise is generated from a rectifying brush when the motor is driven, which adversely affects peripheral circuits. Is a problem. On the other hand, there has been known a vibration generating apparatus in which noise is less generated, in which a magnet floating and fixed by a spring member is vibrated by an attracting action of an electromagnetic coil without using a motor. Although this method has the advantage of relatively simple structure and low cost,
On the other hand, it is difficult to efficiently obtain a large vibration force unless the electromagnetic coil is driven at the resonance frequency determined by the mechanical system (spring mass system and magnet weight) of the vibrating part. Since a suitable driving method that can always be followed cannot be found, the resonance point of the mechanical system tends to shift due to manufacturing variations or aging, and has not yet been put to practical use.

The present invention has been made in view of the above-mentioned problems of the conventional vibration generator, and one of the objects thereof is to make the drive frequency of the electromagnetic coil always follow the mechanical resonance frequency of the vibration generator. Accordingly, it is an object of the present invention to provide a vibration generating device that realizes high-amplitude and high-energy vibrations. Another object is to provide a small and inexpensive mobile phone using the vibration generating device. That is.

[0006]

That is, according to the first aspect of the present invention, there is provided a vibration generating section (2) comprising a movable section (11) floatingly fixed by a spring member (12) and an electromagnetic coil (13). ), The driving voltage (Vd) of the electromagnetic coil (13) is detected at regular intervals in the vibration generator (1) in which the electromagnetic coil (13) is driven by a square wave to obtain an oscillating force. When the induced voltage waveform of the drive voltage (Vd) rises to the right, the drive frequency of the electromagnetic coil (13) is increased, and when the induced voltage waveform rises to the left, the drive frequency of the electromagnetic coil (13) is increased. And a drive control unit (10) for sequentially shifting the drive frequency of the electromagnetic coil (13) to the resonance frequency of the vibration generation unit (2) by performing control to lower the vibration frequency.

In this configuration, if the change of the superimposed waveform at each drive frequency is detected and the drive frequency is corrected so as to be sequentially shifted to the resonance frequency in accordance with each change, the resonance point deviation due to manufacturing variations and aging can be reduced. Correction can be performed, and the vibration generating section can always be vibrated at the resonance point. This makes it possible to realize high-amplitude and high-energy vibration.

According to a second aspect of the present invention, the drive control section (10) detects a waveform of the induced voltage waveform whether rising upward, rising leftward, or a uniform chevron at regular intervals. A circuit (3), an integration circuit (4) that integrates an output of the waveform detection circuit (3) to generate a control voltage (VC2), and a square wave oscillation whose oscillation frequency can be controlled by the control voltage (VC2). And a circuit (5).

In the above configuration, since the shape change of the induced voltage waveform according to the drive frequency is sequentially converted as a change in the DC voltage (control voltage VC2), for example, a voltage controlled oscillator (VCO) is used as a square wave oscillation circuit. By using this, the frequency control is simplified and the circuit configuration can be simplified.

According to a third aspect of the present invention, the waveform detection circuit (3) samples a leading edge of the drive voltage (Vd) for a predetermined time and compares the hold voltage with the drive voltage (Vd). Then, it is characterized by detecting whether the induced voltage waveform rises to the right, rises to the left, or has an even mountain shape.

In this configuration, depending on the state of the induced voltage waveform,
A hold voltage (that is, a reference voltage for comparison) indicated by a broken line in FIGS. 3A to 3C is obtained, and a detection output corresponding thereto is obtained.

According to a fourth aspect of the present invention, the waveform detection circuit (3) samples a leading edge and a trailing edge of the drive voltage (Vd) for a predetermined time and compares each hold voltage. , Whether the induced voltage waveform rises to the right or
Alternatively, it is characterized by detecting whether the shape is a uniform mountain shape.

In this configuration, if each hold voltage is the leading edge <the trailing edge, the induced voltage waveform rises to the right (the resonance point is at a low point), and if the leading edge> the trailing edge, it rises to the left (when the resonance point is high). Yes), if the leading edge is equal to the trailing edge, it can be determined that the shape is a uniform chevron (resonance point). As described above, the waveform detection circuit may have a circuit configuration that compares only the leading edge and the trailing edge of the drive voltage, in addition to the features described in claim 3.

The present invention described in claim 5 is characterized in that the detection of the drive voltage (Vd) is performed at both positive and negative applied voltages in the square wave drive.

When the electromagnetic coil is driven by a square wave, a characteristic waveform shown in FIG. 2 is superimposed on the drive voltage of the coil by the induced voltage due to the vibration of the magnet. That is, when the driving frequency of the coil is higher than the mechanical resonance frequency of the vibration generating unit, the induced voltage waveform to be superimposed becomes a waveform rising to the right as shown in FIG. 2 (f), and when the driving frequency is lower than the resonance frequency. The waveform becomes ascending to the left as shown in FIG. Further, at the time of resonance, a uniform mountain-shaped waveform is obtained as shown in FIG.

The present invention according to claim 6 is characterized in that the detection of the driving voltage (Vd) is performed only at the time of the negative applied voltage in the square wave driving.

In the fifth aspect of the present invention, the induced voltage waveform at the time of the positive / negative applied voltage is detected. However, as in the present configuration, only the induced voltage waveform at the time of the negative applied voltage is detected to correct the drive frequency. It is also possible (see FIG. 6). In this case, there is an advantage that the circuit configuration of the drive control unit can be simplified.

According to a seventh aspect of the present invention, there is provided a portable telephone comprising the vibration generator according to any one of the first to sixth aspects.

The vibration generator according to the present invention is compact and
Since high-amplitude and high-energy vibration can be obtained, it is optimal as a vibration source of a mobile phone, and can sufficiently contribute to miniaturization and cost reduction of a mobile phone.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the vibration generator according to the present invention will be described below with reference to FIGS.

FIG. 1 is a circuit diagram showing a first embodiment of a drive control unit according to the present invention, FIGS. 2 and 3 are diagrams showing waveforms of various parts of the drive control unit in FIG. 1, and FIG. FIG. 5 is a diagram showing a schematic structure, FIG. 5 is a circuit configuration diagram showing a second embodiment of the drive control unit of the present invention, and FIG. 6 is a diagram showing waveforms of various parts of the drive control unit in FIG.

As shown in FIG. 1, a vibration generator 1 according to the first embodiment includes a movable part (permanent magnet 11) movably fixed by a spring member 12 and a vibration generator 2 having an electromagnetic coil 13. And a drive control unit 10 that drives the electromagnetic coil 13 in a square wave at a mechanical resonance frequency.

Hereinafter, a detailed circuit configuration of the drive control unit 10 will be described.

In FIG. 1, reference numeral 3 denotes a waveform detection circuit for detecting a change (upward to the right, upward to the left, or an even mountain) of a superimposed waveform (induced voltage waveform) of the coil drive voltage. Gate circuit U1 (analog switch) that can be turned off and charging capacitor C connected to its output
1 and a comparator U
2 and a gate circuit U that can be turned on / off by a control signal B
3 (analog switch). The midpoint of the two windings L1 and L2 constituting the electromagnetic coil 13 is connected to the negative input of the waveform detection circuit 3.
Further, the midpoint of the coil is connected to a drive power supply Vcc via a resistor R7.

Reference numeral 4 denotes the output Vo of the waveform detection circuit 3.
Is an integrator circuit (smoothing circuit) that generates a control voltage VC2 by smoothing.
The resistors R2 and R3 are bias circuits that apply a predetermined potential to the capacitor C2 when the gate circuit U3 is turned off, and each resistance value is set so that an intermediate potential of the power supply Vcc is obtained.

Reference numeral 5 denotes a square wave oscillation circuit, which is a voltage controlled oscillator (VCO) U4 using the integrated output as an oscillation control voltage.
And external components such as the resistors R4 to R6 and the capacitor C3. This voltage-controlled oscillator U4 has a control voltage VC2
Thus, the oscillation frequency can be freely varied within a certain range. By the way, when the control voltage VC2 decreases, the oscillation frequency increases, and when the control voltage VC2 increases, the oscillation frequency decreases. Also, this voltage controlled oscillator U
4 are connected to the windings L via drivers U5 and U6, respectively.
1, L2.

Next, a series of operations of the drive control unit 10 having the above configuration will be described with reference to FIGS.

The square wave oscillated by the voltage-controlled oscillator U4 in FIG. 1 passes through drivers U5 and U6, as shown in FIGS.
The windings L1 and L2 are driven at the timing shown in FIG. In this case, the windings L1 and L2 are alternately energized at a predetermined timing (ie, at the time of positive / negative applied voltage in the square wave driving). For example, when a current flows through the winding L1, the magnet 11 is attracted to the electromagnetic coil side, and when a current flows through the winding L2, the magnet 11 operates to repel the magnet 11 on the contrary. By repeating this operation, the magnet 11 is vibrated at a predetermined driving frequency.

At this time, a characteristic waveform corresponding to the drive frequency is superimposed on the drive voltage Vd of the electromagnetic coil 13 by the induced voltage due to the vibration of the magnet, as shown in FIGS. FIGS. 2F to 2H show a portion of a superimposed waveform of the drive voltage Vd. That is, when the driving frequency of the electromagnetic coil 13 is higher than the resonance frequency of the vibration generating unit 2, the superimposed waveform becomes a waveform rising to the right as shown in FIG. 2F, and when the driving frequency is lower than the resonance frequency, the waveform of FIG. The waveform becomes ascending to the left. Further, at the time of resonance, a uniform mountain-shaped waveform appears as shown in FIG.

In the waveform detection circuit 3, the drive voltage Vd is sampled for a predetermined period at the timing of the control signal A via the gate circuit U1, and the voltage at the leading edge is charged (held) to the capacitor C1. The hold voltage VC1 at this time becomes the reference voltage of the comparator U2. The comparator U2 compares the hold voltage VC1 with the drive voltage Vd of the electromagnetic coil 13 input to the-terminal, and
If the driving voltage Vd is higher than the reference voltage VC1 shown by the broken lines (f) to (h), the L voltage is output, and if the driving voltage Vd is lower, the H voltage is output. The control signal B is connected to the gate circuit U3, and the gate circuit U3 is controlled so that the gate is opened only while the winding L1 is being driven.

Here, when the driving frequency is higher than the resonance frequency, the output of the comparator U2 is almost L output as shown in FIG. 3A, so that the control voltage VC2 decreases and the oscillation of the voltage control oscillator U4 The frequency transitions to higher. Further, when the driving frequency is lower than the resonance frequency, FIG.
, The output of the comparator U2 is almost an H output, the control voltage VC2 increases, and the voltage-controlled oscillator U4
Oscillation frequency changes to a lower one. When the oscillation frequency reaches the vicinity of the resonance frequency, as shown in FIG. 3C, the output of the comparator U2 is in a state in which H and L are halved, and the control voltage VC2 maintains the potential at that time, so that the oscillation frequency also increases. Maintain the frequency of

The control voltage VC2 is biased to the intermediate potential of the power supply Vcc by the resistors R2 and R3 when the gate circuit U3 is off, that is, while the winding L2 is being driven. The frequency is always set in the vicinity of the resonance frequency, whereby the response speed of the frequency correction can be increased.

The means for detecting the waveform is not limited to the above-described circuit configuration. Although not shown, the leading edge and the trailing edge of the drive voltage Vd are sampled for a predetermined time and the respective hold voltages are compared. It is also possible to detect the rising of the induced voltage waveform, the rising of the left, or the equality. In this case, if each hold voltage is the leading edge <the trailing edge, the induced voltage waveform rises to the right (the resonance point is low),
If the leading edge is greater than the trailing edge, it is determined to rise to the left (when the resonance point is high), and if the leading edge is equal to the trailing edge, it is determined to be a uniform chevron (resonance point).

Next, a second embodiment of the drive control unit 10 of the present invention will be described with reference to FIGS. In the first embodiment, the detection timing of the superimposed waveform at the time of driving the coil is the positive / negative applied voltage in the square wave driving. However, in the second embodiment, the detection timing of the superposed waveform is the negative applied voltage (coil (When the drive is OFF).

The circuit configuration of the drive control unit 10 is almost the same as that of FIG. 1, but in the case of the present embodiment, as shown in FIG. Is connected to the drive power supply Vcc, and the other end is connected to the output of the driver U6 and the negative input of the waveform detection circuit 3.

In the above configuration, the square wave oscillated by the voltage controlled oscillator U4 passes through the driver U6 as shown in FIGS.
The winding L is driven at the timing shown in FIG. At this time,
The drive voltage Vd of the electromagnetic coil 13 includes the coil drive OFF.
The waveforms shown in FIGS. 6E to 6F are superimposed at the timing shown in FIG. As in the first embodiment, the superimposed waveform has a waveform that rises to the right as shown in FIG. 6E when the drive frequency of the electromagnetic coil 13 is higher than the resonance frequency of the vibration generation unit 2, and when the drive frequency is lower than the resonance frequency. As shown in FIG. 6 (f), the waveform rises to the left. Further, at the time of resonance, a uniform mountain-shaped waveform appears as shown in FIG. Subsequent processing is also the same as that of the first embodiment, and the description of the operation is omitted here. In this configuration, the circuit configuration can be simplified as compared with the first embodiment, and the number of components can be reduced, which is effective for miniaturization.

As described above, the present invention focuses on the change in the induced voltage waveform of the electromagnetic coil at each drive frequency, and under the control of the drive control unit 10, when the induced voltage waveform rises to the right, And the drive frequency can be sequentially shifted to the mechanical resonance frequency of the vibration generating unit 2 by lowering the drive frequency when the induced voltage waveform rises to the left. As a result, variations in the mechanical system related to manufacturing (for example, a spring mass system, the weight of a magnet, etc.) and variations in the mechanical system due to aging are corrected, and the drive of the electromagnetic coil can always follow the resonance point. A high amplitude and high energy vibration force can be efficiently obtained from the vibration generation unit 2.

Here, the vibration generator 2 to which the present invention can be applied
FIG. 4 shows a schematic configuration example of the above. The vibration generating section 2 shown in FIG.
The permanent magnet 11 is movably inserted into the coil core, and a coil spring 12 is attached to one end of the permanent magnet 11 to bias the magnet 11 toward the electromagnetic coil 13. Further, the vibration generation unit 2 shown in FIG.
Has a configuration in which an electromagnetic coil 13 housed in a yoke 14 is fixed downward at the tip of a U-shaped leaf spring 12, and the permanent magnet 11 is arranged and fixed below the electromagnetic coil 13. Any of these examples can be drive-controlled by the drive control unit 10 according to the present invention.

As described above, the vibration generator 1 of the present invention
Compared to conventional vibration generators that use a motor and a weight, they are small in size and can provide high-amplitude and high-energy vibrations, making them ideal as vibration sources for mobile phones. It can sufficiently contribute to the trend of cost reduction and price reduction.

[0040]

As described above, in the vibration generator of the present invention, the drive voltage of the electromagnetic coil is detected at regular intervals, and when the induced voltage waveform at that time rises to the right, the drive frequency of the electromagnetic coil is changed. When the induced voltage waveform rises to the left, the drive frequency of the electromagnetic coil is shifted to the mechanical resonance frequency of the vibration generator by sequentially performing control to lower the drive frequency of the electromagnetic coil. The fluctuation of the mechanical system due to the variation and aging of the mechanical system according to the above is sequentially corrected, and the driving of the electromagnetic coil can always follow the resonance point, so that a high amplitude and high energy vibration can be obtained.

Further, if the vibration generator 1 of the present invention is used for a mobile phone, it can sufficiently contribute to a reduction in size and cost of the mobile phone.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a drive control unit according to a vibration generator of the present invention.

FIG. 2 is a diagram showing waveforms of respective units in a drive control unit of FIG.

FIG. 3 is a diagram showing waveforms of a part different from FIG. 2 in the drive control unit of FIG. 1;

FIG. 4 is a diagram illustrating an example of a vibration generating unit.

FIG. 5 is a circuit diagram showing a second embodiment of a drive control unit according to the vibration generator of the present invention.

FIG. 6 is a diagram showing waveforms of respective units in the drive control unit of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vibration generator 2 Vibration generator 3 Waveform detection circuit 4 Integration circuit 5 Square wave oscillation circuit (voltage controlled oscillator) 10 Drive controller 11 Movable part (magnet) 12 Spring member (coil spring, leaf spring) 13 Electromagnetic coil

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) H02K 33/16 H02K 33/16 A F term (Reference) 5C083 AA01 BB31 BB39 DD15 DD16 DD18 FF02 GG07 JJ14 JJ57 5D107 AA03 AA07 BB08 CC09 CC10 CD05 5H633 BB08 GG02 GG13 GG15 GG21 HH03 JA02

Claims (7)

[Claims] 1. A vibration generator (2) comprising a movable part (11) floatingly fixed by a spring member (12) and an electromagnetic coil (13), and the electromagnetic coil (13) is driven by a square wave. A driving voltage (Vd) of the electromagnetic coil (13) is detected at regular intervals, and an induced voltage waveform of the driving voltage (Vd) rises to the right. In the case of (1), the drive frequency of the electromagnetic coil (13) is increased, and when the induced voltage waveform rises to the left, the drive frequency of the electromagnetic coil (13) is decreased successively to thereby control the electromagnetic coil (13). A vibration control device that includes a drive control unit (10) that shifts the drive frequency of the vibration control unit to the resonance frequency of the vibration generation unit (2). 2. The drive control section (10) comprising: a waveform detection circuit (3) for detecting whether the induced voltage waveform rises to the right, rises to the left, or has an even mountain shape at regular intervals.
And integrating the output of the waveform detection circuit (3) with the control voltage (V
The vibration generator according to claim 1, further comprising: an integration circuit (4) for generating C2); and a square wave oscillation circuit (5) whose oscillation frequency can be controlled by the control voltage (VC2). 3. The waveform detection circuit (3) samples a leading edge of the drive voltage (Vd) for a predetermined time, compares the hold voltage with the drive voltage (Vd), and raises the induced voltage waveform to the right. The vibration generator according to claim 2, wherein the vibration generation device detects whether the shape is upward, leftward, or a uniform mountain shape. 4. The waveform detection circuit (3) samples a leading edge and a trailing edge of the drive voltage (Vd) for a predetermined time and compares each hold voltage to determine whether an induced voltage waveform rises to the right or left. The vibration generator according to claim 2, wherein the vibration generation device detects whether the shape is rising or a uniform mountain shape. 5. The method according to claim 1, wherein the detection of the drive voltage (Vd) is performed at any of positive and negative applied voltages in the square wave drive. Vibration generator. 6. The vibration generator according to claim 1, wherein the detection of the drive voltage (Vd) is performed only when a negative voltage is applied in the square wave drive. 7. A mobile phone comprising the vibration generator according to claim 1. Description: