JPH09267075A - Vibration generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to constitute a vibration generator to a small size at a low cost by making it possible to obtain large vibration with small energy and simplifying the constitution of not only the mechanism section but the driving circuit itself as well. SOLUTION: A driving coil 26 and detecting coil 27 which are concentrically disposed are partly advanced without contact into a magnetic gap 59 of an inertia section 50 supported by an elastic supplying section 40. The driving circuit 30 is composed of a first resistor 33 connected between one of a power source 37 and one end of the detecting coil 27, a second resistor 34 connected between one end of the detecting coil 27 and the other of the power source 37 and a transistor(TR) 35 connected at its base to the other end of the detecting coil 27 and connected at its collector to the other end of the driving coil and is connected at its emitter to the other of the power source. The current flowing from the connection point of the first and second resistors 33, 34 to the base of the TR 35 via the detecting coil 27 is intermittently shut off by the electromotive force generated at both ends of the detecting coil 27 according to the movement of the inertia section 50, by which the vibration of the inertia section 50 is maintained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for reducing the size and cost of a vibration generator used in a portable calling device such as a pager.

[0002]

2. Description of the Related Art A portable calling device has a built-in vibration generator for notifying the wearer of the presence or absence of a call by mechanical silent vibration.

Among the vibration generators of this type, those incorporated in a particularly small calling device are required to have a simple structure, sufficient vibration can be obtained, and a small current consumption.

In order to meet this demand, instead of the conventional structure in which an eccentric weight is rotationally driven by a motor, an electric current is intermittently passed through a coil that interlinks with a magnetic flux generated by the permanent magnet. A vibration generator having a structure in which a permanent magnet is vibrated with respect to the coil by intermittently generating a force between the coil and the coil has been realized. By adopting such a structure, the vibration mechanism can be downsized. Became possible.

By the way, in a vibration generator having such a mechanism, for example, as shown in FIG. 9, a pulse signal output from the oscillation circuit 1 is applied to the base of the transistor 2 to turn on / off the transistor 2. A coil 3 connected between the power supply Vc and the collector of the transistor 2.
A drive circuit that intermittently supplies a current has been adopted.

[0006]

However, in the drive circuit for turning on / off the transistor 2 by the pulse signal output from the oscillation circuit 1 as described above, there are many circuit components, so that the cost is high and the mechanism is downsized. It was difficult to embed the entire circuit in the unit.

Further, since vibration is electrically forcibly generated, the vibration efficiency is low, and a large amount of energy is required to obtain a large motion.

The present invention solves this problem and provides a vibration generator capable of obtaining a large vibration with a small amount of energy, simplifying the structure of not only the mechanical section but also the drive circuit itself, and being compact and inexpensive. It is an object.

[0009]

In order to achieve the above-mentioned object, a vibration generator according to the present invention comprises a substrate, a cylindrical outer yoke whose one end face side is closed, and a center one end face of the outer yoke. Of the permanent magnet having a fixed magnetic pole surface, an inner yoke fixed to the other magnetic pole surface of the permanent magnet to form a magnetic gap between the inner yoke and the inner peripheral wall of the outer yoke, and an elastic member. An elastic support portion that supports the inertia portion so that the inner yoke faces the one surface side of the substrate so that the inner yoke can approach and separate from the substrate; A drive coil fixed to one surface side of the substrate in a state where a part of the drive coil is inserted into a magnetic gap, and a detection coil wound concentrically with the drive coil so that a part of the inertia part is inserted into the magnetic gap. The coil and the drive whose one end is connected to one of the power sources. And a drive circuit for intermittently applying a current to the coil to vibrate the inertial portion with respect to the substrate, the drive circuit being connected between one of the power supply and one end of the detection coil. A first resistor and a second resistor connected between one end of the detection coil and the other of the power supply
And a base connected to the other end of the detection coil,
A transistor having a collector connected to the other end of the drive coil and an emitter connected to the other of the power supply; and a base of the transistor from a connection point of the first and second resistors via the detection coil. Is intermittently interrupted by the electromotive force generated at both ends of the detection coil in accordance with the movement of the inertial portion, and the vibration of the inertial portion is maintained.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a diagram showing the appearance of a vibration generator 20 to which the present invention is applied, FIG. 2 is a plan view thereof, FIG. 3 is a side view thereof, FIG. 4 is a sectional view taken along line AA of FIG. 2, and FIG. 5 is an exploded view. Is.

In these figures, the substrate 21 of the vibration generator 20 is formed of synthetic resin into a substantially rectangular shape, and a flange 21a is provided on the peripheral edge thereof. Board 21
Support shafts 22 and 22 are provided upright at the corners on the short side of the upper surface 21b of the upper side 21b, and a locking portion cut out inward for fixing a cover 60 described later at the center of the two long side edges. 23, 23 are provided.

A coil block 24 is fixed to the center of the upper surface 21b of the substrate 21. Coil block 24
Is the coil substrate 25 and the circular portion 25a of the coil substrate 25.
It is composed of an air-core drive coil 26 which is wound in a cylindrical shape on the upper side, and a detection coil 27 which is wound so as to be in close contact with the outer circumference (may be the inner circumference) of the drive coil 26, and the lower surface side of the coil substrate 25 is It is fixed to the upper surface 21b of the substrate 21. The drive coil 26 has a large wire diameter and a small number of turns to flow a large current, and the detection coil 27 has a small wire diameter and a large number of turns to generate a large electromotive force.

The drive coil 26 and the detection coil 27 are
It is connected to the drive circuit 30 formed on the rectangular portion 25b of the coil substrate 25. The drive circuit 30 has a power supply terminal 3
Power is supplied from Nos. 1 and 32, and an electric current is intermittently applied to the drive coil 26 to vibrate an inertial portion described later.

Above the substrate 21, an elastic supporting member 40 having a parallel four-bar link structure is arranged. Elastic support member 4
0 is a fixed piece 41 made of synthetic resin in a substantially prismatic shape,
A supporting piece 42 which is made of synthetic resin and has a rectangular column shape which is approximately the same length as the fixing piece 41 and is thinner than the fixing piece 41 and which faces the fixing piece 41 in parallel.
The four connecting pieces 43 connected in a step form a rectangular frame shape.

A guide groove 44 is provided in the center of the side surface of the fixed piece 41 on the side of the support piece 42, and a guide groove 44 for guiding the vertical movement of an inertial portion 50, which will be described later, is provided. Holes 45, 45 for inserting the supported support shafts 22, 22 are provided so as to vertically pass therethrough. The center of the lower portion of the fixed piece 41 is cut out to form a space for accommodating the drive circuit 30, and support shafts 46 and 46 are provided upright on both ends of the upper surface of the support piece 42. Each connecting piece 43 is a thin leaf spring 43 whose middle part is covered with synthetic resin.
The fixed piece 41 and the support piece 4 are formed by a.
The connecting portion with 2 can be bent and deformed in the vertical direction by the elasticity of the leaf spring 43a.

The elastic support member 40 is supported by the support shafts 22, 22 inserted into the holes 45, 45 of the fixed piece 41 such that both ends of the lower surface of the fixed piece 41 are in close contact with the upper surface of the substrate 21. Due to the elasticity of the leaf spring 43a of each connecting piece 43, the supporting piece 42 side can be moved up and down substantially parallel to the fixed piece 41 side. The tip ends of the support shafts 22 and 22 are fixed so that the support member 40 does not come off from the substrate 21 by being spread by heat on the upper surface side of the fixing piece 41 of the support member 40.

An inertial member 50 composed of an outer yoke 51, a permanent magnet 57 and an inner yoke 58 is supported on the support piece 42. The outer yoke 51 has a mounting portion 52 formed in a substantially T shape, a disc portion 53 having a peripheral edge continuous to the tip of the central piece 52a of the mounting portion 52, and a concentric projection from the lower surface of the disc portion 53. And the formed cylindrical portion 54.

Elastic support members 40 are provided at both ends of the mounting portion 52.
Holes 55, 55 through which the support shafts 46, 46 projecting from the upper surface of the support piece 42 are inserted, and the tips of the support shafts 46, 46, through which the holes 55, 55 are inserted, are spread by heat to expand the outer yoke. 51 is fixed to the support piece 42.

The disc portion 53 is located inside the elastic support member 40 with a gap, and the guide projection 56 is loosely fitted in the guide groove 44 of the fixed piece 41 on the peripheral edge of the fixed piece 41 side. Is projected on.

A columnar permanent magnet 57 is fixed to the inside of the cylindrical portion 54 so that one magnetic pole surface thereof is closely attached. An inner yoke 58 having the same diameter as that of the permanent magnet 57 is fixed to the other magnetic pole surface of the permanent magnet 57, and has a ring shape between the inner circumference of the cylindrical portion 54 of the outer yoke 51 and the outer circumference of the inner yoke 58. The magnetic gap 59 is formed. The drive coil 26 of the coil block 24 and the upper portion of the detection coil 27 enter the magnetic gap 59 in a non-contact state.

The cover 60 is made of metal and is formed in a box shape whose lower surface is open. The substrate 21 is locked by the stoppers 23, 23.
Fixed to

On the other hand, the drive circuit 30 is composed of first and second resistors 33 and 34 and a transistor 35 which are connected in series between the power supply terminals 31 and 32 as shown in FIG. That is, the base of the transistor 35 has the first and second bases.
Is connected to the connection point of the resistors 33 and 34 of the power supply terminal 3 through the detection coil 27, and the collector is connected through the drive coil 26
1 and the emitter is connected to the power supply terminal 32.

In the drive circuit 30, when the transistor 35 is turned on and a current flows through the drive coil 26 so that the inertial portion 50 moves in a direction away from the substrate 21, for example, the detection coil 27 moves as the inertial portion moves. With the counter electromotive force generated at both ends of the current, the current flowing from the connection point of the first and second resistors 33 and 34 to the base of the transistor 35 is cut off.
The above operation is repeated to intermittently supply a current to the drive coil 26.

The capacitor 36 connected between the connection point of the first and second resistors 33 and 34 and the base of the transistor 35 is electromagnetically coupled between the drive coil 26 and the detection coil 27 and between the windings. This is to prevent the generation of high frequency oscillation due to the electrostatic capacity of the.

Further, the resistance value of the first resistor 33 is set to a resistance value capable of supplying a base current necessary for supplying a sufficient current to the drive coil 26 when the transistor 35 is in an ON state, Here, the first and second resistors 3
3, 34 are set to the same resistance value.

Here, for example, the voltage Vc of the power source is 3V,
The first and second resistors 33 and 34 are both 120 ohms, the DC resistance of the detection coil 27 is 140 ohms, and the base-emitter voltage Vbe of the transistor 35 is 0.7V.
The base current Ib when the electromotive force of the detection coil 27 is zero is 2.75 mA.

Further, the DC resistance value of the drive coil 26 is set to 15
If it is ohmic, the maximum current that can be passed from the power supply to this drive coil is 200 mA, and this current value can be achieved by using a transistor with a current amplification factor of about 73 (= 200 / 2.75) or more. You can Since a normal transistor has a current amplification factor higher than this, a sufficient current can be passed through the drive coil 26 by the above base current.

Further, the maximum value of the voltage at the connection point of the first and second resistors 33 and 34 is 1 / th of that when the power supply voltage is 3V.
2 is 1.5 V, and when the electromotive force generated in the detection coil 27 is lower than −0.8 V with reference to the connection point of the first and second resistors 33 and 34, the base current does not flow in the transistor 35. The transistor 35 is turned off.

The drive circuit 30 is supplied with power from a battery 37 via a switch circuit 38. The switch circuit 38 is turned on by a control circuit (not shown) when a call is required.

Next, the operation of the vibration generator 20 will be described with reference to FIG. In the following description, it is assumed that the constants of the drive circuit are equal to those described above.

As shown in FIG. 7A, when power is externally supplied to the power supply terminals 31 and 32 of the vibration generator 20 at t ₀ , the connection points of the first and second resistors 34 and 34 are connected. The voltage Va of the detection coil 27 is, as shown in FIG.
Due to the transient response when the power is turned on, the voltage temporarily rises from zero volt to 1/2 of the power supply voltage Vc.

As the transient response of the detection coil converges, a base current Ib flows through the transistor 35 through the detection coil 27 as shown in FIG.
Depending on b, as shown in FIG.
The collector-emitter of is turned on and the current flows to the drive coil 26.

This current is applied to the magnetic gap 5 of the inertia section 50.
Since it is orthogonal to the magnetic flux crossing 9, the strong force is generated between the drive coil 26 and the inertial portion 50 according to Fleming's law, for example, in the direction in which the drive coil 26 exits from the magnetic gap 59. Therefore, the inertial portion 50 supported by the elastic support member 40 moves in the direction away from the substrate 21, that is, in the direction in which the magnetic flux intersecting the detection coil decreases, as shown in FIG. Therefore, as shown in (e) of FIG. 7, an electromotive force E is generated at both ends of the detection coil 27 in a direction to prevent the decrease of the magnetic flux.

This electromotive force E is generated by the first and second resistors 33, 3
When the electromotive force increases in the negative direction with respect to the connection point side of 4 as a reference, that is, in the direction of decreasing the base current of the transistor 35, and becomes less than −0.8 V described above at time t ₁ , the base current of the transistor 35 increases. Ib stops flowing and the transistor 35 is turned off.

When the transistor 35 is turned off, as shown in FIG. 8 (b), the inertial portion 50 has the elastic supporting member 4
The elastic return force of 0 moves in the direction of approaching the substrate 21.

Therefore, the electromotive force E of the detection coil 27 rises and exceeds -0.8 V at t ₂ . Therefore, the base current flows through the transistor 35 again, and the transistor 3
5 is turned on.

Thereafter, this operation is repeated until the inertia part 50
Oscillates continuously with respect to the substrate 21 at the natural frequency of the oscillating system consisting of the inertia part 50 and the elastic support part, and the wearer feels this vibration and knows that they call each other.

When the elastic supporting member 40 having the parallel four-bar link structure is used as in the vibration generator 20, the inertia part 50 including the outer yoke 51, the permanent magnet 57 and the inner yoke 58 is vertically moved substantially in parallel. Since it moves, even if the magnetic gap 59 is narrowed, the drive coil 2 of the coil block 24 is moved.
There is no need to worry about contacting 6 and the detection coil 27. Therefore, the magnetic flux can be concentrated in the narrow magnetic gap 59, a large vibration amplitude can be obtained with a small amount of electrical energy, and extremely efficient vibration can be obtained.

Further, as described above, the structure of the drive circuit 30 itself is very simple and can be formed on the substrate 21 or in a small space in the vibrating device, so that the entire device can be downsized.

[0040]

Other Embodiments In the above embodiment, the inertial portion has a substantially circular shape, and the drive coil and the detection coil have a cylindrical shape corresponding to the magnetic gap, but this limits the present invention. Instead, for example, the entire inertial portion may be formed into an elliptical shape or a rectangular shape, and the shapes of the drive coil and the detection coil may be matched with the shape of the magnetic gap.

Further, in the above embodiment, one end of the inertial portion is supported by the elastic support member of the four-bar link structure, but a structure may be adopted in which the outer periphery of the inertial portion is supported by a plurality of independent elastic support members. .

In the drive circuit of the above embodiment, the NP
Although the N-type transistor is used, a PNP-type transistor may be used. Further, not only one element inside but a transistor in which two elements are Darlington-connected inside may be used.

[0043]

As described above, according to the vibration generator of the present invention, the inertia portion composed of the outer yoke, the permanent magnet and the inner yoke can be moved toward and away from the substrate by the elastic supporting member made of the elastic material. And the drive coil and the detection coil are concentrically arranged on the substrate so that a part of them enters the magnetic gap of the inertial material to form a mechanical section, and between one of the power supply and one end of the detection coil. Connected to the first resistor, a second resistor connected between one end of the detection coil and the other of the power source, the base of the other end of the detection coil, and the collector of the other end of the drive coil. A drive circuit is configured with a transistor that is connected and has an emitter connected to the other side of the power supply, and the current flowing from the connection point of the first and second resistors to the base of the transistor via the detection coil is transferred to the movement of the inertia part. When It is to be intermittently blocked by the electromotive force generated across the detecting coil, so as to maintain the vibration of the inertial unit.

Therefore, a large vibration can be obtained with a small amount of energy, and not only the structure of the mechanical section but also the structure of the drive circuit itself is very simple, and the entire apparatus can be made compact and inexpensive.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of an embodiment of the present invention.

FIG. 2 is a plan view of one embodiment.

FIG. 3 is a side view of one embodiment.

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is an exploded perspective view of one embodiment

FIG. 6 is a circuit diagram of a drive circuit

FIG. 7 is an operation explanatory diagram of a drive circuit.

FIG. 8 is an explanatory diagram of the operation of the mechanism section.

FIG. 9 is a diagram showing a configuration of a conventional drive circuit.

[Explanation of symbols]

 20 vibration generator 21 substrate 24 coil block 26 drive coil 27 detection coil 30 drive circuit 33 first resistance 34 second resistance 35 transistor 40 elastic support member 50 inertia part 51 outer yoke 57 permanent magnet 58 outer yoke 59 magnetic gap

Claims (1)

[Claims] 1. A substrate, a cylindrical outer yoke whose one end face is closed, a permanent magnet having one pole face fixed to the center of one end face of the outer yoke, and the other pole face of the permanent magnet. An inertia part that is fixed and that includes an inner yoke that forms a magnetic gap with the inner peripheral wall of the outer yoke; and an inertia part that is made of an elastic material and that has the inner yoke facing one surface side of the substrate. An elastic supporting portion that supports the substrate so that the substrate can be moved toward and away from the substrate, and the elastic supporting portion is wound in an air-core tube shape and is fixed to the one surface side of the substrate with a part of the elastic core portion entering the magnetic gap of the inertial portion. Drive coil, a detection coil wound concentrically with the drive coil so that a part of the drive coil enters the magnetic gap of the inertia part, and one end of which is intermittent with respect to the drive coil connected to one of the power sources. Current is applied to move the inertial part to the substrate. A drive circuit for vibrating, the drive circuit comprising: a first resistor connected between one of the power sources and one end of the detection coil; and a first resistor connected between one end of the detection coil and the other power source. A second resistor connected to the detection coil, a base connected to the other end of the detection coil, a collector connected to the other end of the drive coil, and an emitter connected to the other end of the power supply; A current flowing from the connection point of the first and second resistors to the base of the transistor via the detection coil is intermittently interrupted by an electromotive force generated at both ends of the detection coil as the inertial portion moves. And a vibration generator configured to maintain the vibration of the inertial portion.