WO2007073125A1

WO2007073125A1 - Pin-type vibrotactile device

Info

Publication number: WO2007073125A1
Application number: PCT/KR2006/005688
Authority: WO
Inventors: Tae-Jeong Jang
Original assignee: Knu-Industry Cooperation Foundation
Priority date: 2005-12-23
Filing date: 2006-12-22
Publication date: 2007-06-28
Also published as: KR100773061B1; KR20070067448A

Abstract

A pin-type vibrotactile device comprises a coil formed by winding conductive wire in a cylindrical shape where a hole is formed in the center thereof, the coil receiving electric power from an external power supply so as to form a magnetic field within the conductive wire; a vibrotactile module having a body and a pin formed to project outward from an upper portion of the body; a magnet coupled and fixed to the body of the vibrotactile module, the magnet forming a magnetic field so as to vertically move through the interaction with the coil; and a housing for forming the exterior of the device, the housing having a hole formed on a predetermined position of an upper surface thereof, the position corresponding to the pin of the vibrotactile module, and a support for the coupling to the coil, the support being formed on a lower surface of the housing.

Description

Description PIN-TYPE VIBROTACTILE DEVICE

Technical Field

[1] The present invention relates to a pin-type vibrotactile device, which vertically moves a pin by using the interaction between a current flowing in a coil and a magnetic flux produced from a permanent magnet such that vibration stimulus caused by the pin can directly delivered.

[2]

Background Art

[3] In a conventional pin-type vibrotactile device such as a vibrotactile mouse, a vibration generating device or the like, a small-sized motor is used to vibrate the overall body of the device. Although devices for generating vibration by using a pin have been already provided, most of them have been made as subsidiary devices for blind or deaf people.

[4] Further, most of the conventional vibrotactile devices use only a plate-shaped piezo driver, but do not use a pin. In Korean Patent Application No. 10-2002-0023099 disclosed by the present applicant, entitled "Vibrotactile display module and multichannel vibrotactile device", a plate-shaped driver to which two piezo plates are attached and pins which are densely arranged on the plate-shaped driver are used together. In such a vibrotactile device, when a sine wave or similar wave of voltage is applied to both surfaces of two piezo plates, one surface expands and the other surface contracts. Such expansion and contraction are repeated so that the plate-shaped piezo driver is alternately bent in one direction to generate vibrations. The generated vibrations are delivered to the plurality of pins, thereby stimulating a body region.

[5] As for a power source of the conventional vibrotactile device, various equipments are used, such as a piezo driver, EAP (electro active polymer), SMA (shape memory alloy), and a motor. The power sources excluding the motor require a relatively high voltage or need a separate cooling device. Therefore, the power sources have a limit in low power consumption and miniaturization. Further, in a vibrotactile mouse or a mobile phone, a small-sized motor is used to vibrate the overall body thereof, without using pins. Therefore, the range of application is limited.

[6]

Disclosure of Invention Technical Problem

[7] An advantage of the present invention is that it provides a pin-type vibrotactile device which vibrates a pin by using a pushing or pulling force between a current flowing in a coil and a magnet such that vibration stimulus caused by the pin can directly delivered to a body region.

[8]

Technical Solution

[9] According to an aspect of the invention, a pin-type vibrotactile device comprises a coil formed by winding conductive wire in a cylindrical shape where a hole is formed in the center thereof, the coil receiving electric power from an external power supply so as to form a magnetic field within the conductive wire; a vibrotactile module having a body and a pin formed to project outward from an upper portion of the body; a magnet coupled and fixed to the body of the vibrotactile module, the magnet forming a magnetic field so as to vertically move through the interaction with the coil; and a housing for forming the exterior of the device, the housing having a hole formed on a predetermined position of an upper surface thereof, the position corresponding to the pin of the vibrotactile module, and a support for the coupling to the coil, the support being formed on a lower surface of the housing.

[10] According to another aspect of the invention, a pin-type vibrotactile device comprises a coil formed by widing conductive wire in a cylindrical shape where a hole is formed in the center thereof, the coil receiving electric power from an external power supply so as to form a magnetic field within the conductive wire; a vibrotactile module having a body and a pin formed to project outward from an upper portion of the body; a magnet coupled and fixed to the body of the vibrotactile module, the magnet forming a magnetic field so as to vertically move through the interaction with the coil; a support coupled to the coil so as to fix the coil; and a housing for forming the exterior of the device, the housing having a hole formed on a predetermined position of an upper surface thereof, the position corresponding to the pin of the vibrotactile module.

[11] According to a further aspect of the invention, the vibrotactile module further includes a pin guide shaft formed in a lower portion of the body, the pin guide shaft being formed in the center direction of the coil.

[12] According to a still further aspect of the invention, the vibrotactile module has a plate-shaped wing attached thereto, the plate-shaped wing strengthening the coupling between the magnet and the pin and maintaining the relative position between the pin and the magnet at a constant distance.

[13] According to a still further aspect of the invention, the housing has a coil fixing board attached to the lower surface thereof, the coil fixing board fixing both ends of the conductive wire composing the coil such that both ends are connected to an external voltage along wiring lines. [14] According to a still further aspect of the invention, the vibrotactile module has a spring attached thereto, the spring restoring the pin, which performs a vertical movement, to the former state.

Advantageous Effects

[15] According to the present invention, information is delivered by a vibrotactile sensation of the pin, which is directly delivered to a body region, or vibration stimulus or physical therapy effect can be provided. The device can be simply implemented by using the property between the coil and the magnet and can be implemented at a low cost. Further, the shape, amplitude, and frequency of waveform applied to the coil are changed so that various patterns of vibrations can be easily generated.

[16]

Brief Description of the Drawings

[17] Fig. 1 is an exploded perspective view of a pin-type vibrotactile device according to an embodiment of the present invention.

[18] Fig. 2 is a sectional view of the pin-type vibrotactile device.

[19] Fig. 3 is a schematic view illustrating the operation of the pin-type vibrotactile device according to the embodiment of the invention.

[20] Fig. 4 is a diagram for explaining the shape of a coil fixing board which is added to the pin-type vibrotactile device of the invention.

[21] Fig. 5 A to 5C are diagrams showing various waveforms which can be applied to a coil of the pin-type vibrotactile device of the invention.

[22] Fig. 6A to 6C are diagrams showing waveforms of a PWM method for adjusting an amplitude and waveform of the pin-type vibrotactile device of the invention.

[23] Fig. 7 is a sectional view of a vibrotactile module in which a pin guide shaft is omitted.

[24] Fig. 8 is a schematic perspective view for explaining another pin-type vibrotactile device according to the invention.

[25]

Best Mode for Carrying Out the Invention

[26] Hereinafter, a pin-type vibrotactile device according to an embodiment of the invention will be described with reference to the drawings.

[27] Fig. 1 is an exploded perspective view of the pin-type vibrotactile device according to the invention, and Fig. 2 is a sectional view of the pin-type vibrotactile device. As shown in Figs. 1 and 2, the pin-type vibrotactile device of the invention includes a magnet 20, a coil 40, a vibrotactile module 30, and a housing 10. The vibrotactile module 30 has a body 33, a pin 31 formed in the upper portion of the body, and a pin guide shaft 35 formed in the lower portion of the body. The housing 10 has a pin guide hole 11 formed on the upper surface thereof and a support 13 formed on the lower surface thereof.

[28] The body 33 of the vibrotactile module 30 is a portion which is coupled to the magnet 20. A plate-shaped wing 37 may be additionally attached to the vibrotactile module 30 such that, when the pin and the magnet are coupled, the coupling strength therebetween can be increased and the relative position therebetween can be maintained at a constant distance.

[29] The vibrotactile module 30 has the pin 31 formed on the upper end portion of the body, the pin 31 projecting at right angle or at a substantially right angle. The pin 31 should be constructed to have such a length that, even when the vibrotactile module 30 moves to the downmost position so as to be located on the bottom, the pin 31 does not completely come off from the pin guide hole 11 of the housing. The pin may be formed of plastic or metal. However, considering a characteristic of the pin which directly stimulates a skin, it is preferable to use a harmless material.

[30] In order to enhance a restoring force of the pin 31 performing a vertical movement, a spring can be attached to the upper or lower portion of the pin 31. Such a structure restores the pin to the former position by using a restoring force of the spring, when a unipolar waveform of current is applied to the coil such that the pin can move only in one direction.

[31] The spring can be designed in a circular shape, a plate shape, or a leaf shape. When the force of the spring is excessively strong, the projecting force of the pin is weakened. On the contrary, when the force of the spring is excessively weak, a natural frequency is reduced so that a frequency is also reduced at which the vibration can be performed. Therefore, the force of the spring should be adjusted in consideration of the above-described characteristic. However, the spring is not necessarily needed. In this case, when a method of changing the direction of current flowing in the coil is used, the vertical movement of the pin can be effectively implemented without the spring.

[32] The lower end portion of the body of the vibrotactile module serves to prevent the vibrotactile module from losing its balance when the combined structure of the magnet 20 and the vibrotactile module 30 performs a vertical movement. The vibrotactile module has the pin guide shaft 35 formed in the center direction of the coil. The pin guide shaft is positioned in a hole formed in the center of the support 13 on the lower surface of the housing, the support 13 fixing the coil. In this case, the pin guide shaft 35 is not necessarily needed. As shown in Fig. 7, when the distance between the magnet 20 and the housing 10 is set properly, the pin guide shaft and the hole of the support 13 do not need to be provided. Fig. 7 is a sectional view of a vibrotactile module in which the pin guide shaft is omitted. As shown in Fig. 7, the vibrotactile module can be composed of only the body 31 and the pin 33 formed on the upper surface of the body 33. However, when balancing is performed in the lower portion of the vibrotactile module, it is advantageous for a stable operation.

[33] The coil 40 is constructed by winding conductive wire in a cylindrical shape in which a hole is formed in the center thereof. Further, the coil 40 is fixed through the coupling to the support 13 formed on the lower surface of the housing.

[34] When the conductive wire is wound, the thickness of conductive wire and the size and outer shape of the coil may be considered. Under such a consideration, the conductive wire can be properly wound so as to achieve the desired DC resistance. Further, when electric power is applied through an external power supply, a current flows in the coil. The power consumption is determined by a voltage to be applied. When electric power is used which can drive one vibration motor mounted in a mobile phone, the electric power can apply a proper level of vibration stimulus to a human skin. In consideration of a characteristic of the invention where the pin is protruded so as to directly deliver stimulus and a characteristic where the sensitivity to the vibration stimulus is different depending on each body region, the power consumption should be adjusted in accordance with the use.

[35] The magnet 20 forms a magnetic field. The vertical movement is performed by an interaction between a magnetic flux formed inside the magnet and a current flowing in the coil 40, that is, a pulling or pushing force between the magnet and the coil. As a result, the pin of the vibrotactile module 30, which is coupled to the magnet so as to compose one structure, can move vertically. As for the magnet, such a material as neodymium having a large magnetic force per unit volume is preferably used.

[36] The housing 10 forms the exterior of the pin-type vibrotactile device according to the invention. The housing 10 has the pin guide hole 11 formed in a position on the upper surface thereof, the position corresponding to the pin 31 of the vibrotactile module. The upper surface should be formed to have such a depth that the vertical movement of the pin can be accelerated.

[37] Inside the housing, a space should be secured in which the structure composed of the magnet 20 and the vibrotactile module 30 can move vertically. The space should be formed to have such a height that the pin projecting outside the device through the pin guide hole 11 of the housing stimulates a skin but does not cause damage on the skin, even when the pin of the vibrotactile module is pushed at the maximum height.

[38] On the lower surface of the housing, the support 13 is formed so that the coil 40 can be easily fixed. The support has a hole formed in the center thereof. When the pin guide shaft 35 formed in the lower portion of the vibrotactile module 30 moves vertically, the hole prevents the pin guide shaft 35 from losing its balance. The hole should be formed to have such a length that the pin guide shaft 13 does not come off from the support 13 when the vibrotactile module is pushed at the maximum height. However, when the vibrotactile module is composed of only the pin 31 and the body 33, the hole of the support 13 may be omitted.

[39] The bottom surface of the housing serves to fix both ends of the conductive wire wrapping the coil. As shown in Fig. 4, a printed board may be additionally installed on the bottom surface of the housing such that both ends of the conductive wire are soldered so as to be easily attached thereto.

[40] Fig. 4 is a diagram showing the shape of a coil fixing board which can be added to the pin-type vibrotactile device. Both ends A and B of the conductive wire wrapping the coil are connected and fixed to portions A' and B' of the coil fixing board, respectively. Further, both ends A and B are connected to an external voltage along wiring lines of the printed board.

[41] Fig. 8 is a diagram illustrating another pin-type vibrotactile device according to a modification of the invention. More specifically, a housing 50 forms the exterior of the device and has a pin guide hole 51 formed in a predetermined position on the upper surface thereof, the position corresponding to a pin 61 of a vibrotactile module 60. The exterior of the housing can be formed in various shapes, in addition to a square-pillar shape shown in Fig. 8. The vibrotactile module 60 and the coil 40 are the same components as those of the above-described embodiment, and thus the descriptions thereof will be omitted.

[42] As shown in Fig. 8, a support 70 can be constructed as a separate structure between the coil 40 and the magnet 80, while the support is formed on the lower surface of the housing in the embodiment. The support 70 has the same function as that of the support of the embodiment. The support 70 is coupled to the coil 40 so as to fix the coil 40. Further, the support 70 has a hole 71 formed in the center thereof so as to support a pin guide shaft 63 of the vibrotactile module 60 such that the vibrotactile module 60 stably performs a vertical movement.

[43] The coil fixing board 90 is formed between the coil 40 and the lower surface of the housing 50 such that both ends A and B of the conductive wire forming the coil 40 are attached to the coil fixing board 90 and are connected to an external voltage through wiring lines. As for the coil fixing board 90, a printed board or the like can be used. In this case, a small-sized driver IC for driving the coil may be attached to the rear surface of the printed board.

[44] The pin-type vibrotactile device according to the inveniotn has the above-described construction. Hereinafter, the operation of the pin-type vibrotactile device will be described with reference to the accompanying drawings.

[45] Fig. 3 is a schematic view illustrating the operation of the pin-type vibrotactile device according to the embodiment of the invention.

[46] When a current is applied to the coil through an external power supply, a magnetic field is produced within the coil. Between this magnetic field and a magnetic field caused by the magnet, a force acts in a direction based on the Fleming's left hand rule. That is, the direction of the magnetic field produced within the coil changes in accordance with the direction of current flowing in the coil. Accordingly, a pulling or pushing force is generated between the coil and the magnet. The structure composed of the magnet and the vibrotactile module is moved vertically by the pulling or pushing force such that the pin formed in the upper portion of the body is vertically moved.

[47] More specifically, when a current (+ , -) is applied to the coil 40 through an external power supply as shown in Fig. 3, a magnetic field (N or S) is produced. Accordingly, a pushing force acts between the coil 40 and the magnet 20, as shown in Fig. 3A. Then, the magnet 20 is vertically pushed up, as shown in Fig. 3A'.

[48] As the magnet is vertically pushed up, the pin 31 of the vibrotactile module, which is coupled to the magnet so as to form one structure, is protruded outside the device through the pin guide hole 11 of the housing 10. The protruded pin directly stimulates a human skin.

[49] In this state, when the direction of current flowing in the coil is changed, the direction of the magnetic field flowing in the coil is also changed into the reverse direction (Fig. 3B). Then, a pulling force acts between the coil 40 and the magnet 20. Accordingly, the magnet 20 is vertically moved downward, and the pin 11 which has been stimulating the skin is also moved downward so as to return to the original position.

[50] As such, when the pulling force and the pushing force repeatedly act at high frequency of several Hz to several hundreds Hz, the vibrations of the pin are generated. As shown in Fig. 5, various waveforms such as a sine wave (Fig. 5A), a chopping wave (Fig. 5B), and a square wave (Fig. 5C), which have a polarity (+ or -), are applied so as to generate various types of vibrations.

[51] The adjustment of amplitude and waveform can be easily performed by using a

PWM (pulse width modulation) method. Fig. 6 is a diagram showing waveforms of the PWM method. The PWM method is where the width of active state pulse within a predetermined period is changed so as to change an on/off duty rate within the period or an output signal is filtered and converted into a corresponding direct current level so as to perform DC voltage control.

[52] When a basic frequency of PWM waveform to be applied is set to be sufficiently larger than a natural frequency of the module composed of the magnet and the pin or a band width in consideration of frequency response characteristic, a low-frequency filter function is performed, thereby obtaining the same effect when an average voltage is applied. In the pin-type vibrotactile device, a duty rate of waveform is changed by the PWM method such that a desired average- voltage waveform can be obtained. [53] As for a method of flowing a bipolar current into a coil, an H-bridge driver can be used, which is frequently used for controlling a DC motor. When the H-bridge driver is used, the direction of a voltage applied to the coil can be easily changed even by a single power supply. Particularly, when a small-sized (for example, 2mm x 2mm x 0.5mm) H-bridge driver is used, a driver chip itself can be soldered on the rear surface of the coil fixing board together with a circuit.

Claims

[1] A pin-type vibrotactile device comprising: a coil formed by winding conductive wire in a cylindrical shape where a hole is formed in the center thereof, the coil receiving electric power from an external power supply so as to form a magnetic field within the conductive wire; a vibrotactile module having a body and a pin formed to project outward from an upper portion of the body; a magnet coupled and fixed to the body of the vibrotactile module, the magnet forming a magnetic field so as to vertically move through the interaction with the coil; and a housing for forming the exterior of the device, the housing having a hole formed on a predetermined position of an upper surface thereof, the position corresponding to the pin of the vibrotactile module, and a support for the coupling to the coil, the support being formed on a lower surface of the housing.

[2] A pin-type vibrotactile device comprising: a coil formed by widing conductive wire in a cylindrical shape where a hole is formed in the center thereof, the coil receiving electric power from an external power supply so as to form a magnetic field within the conductive wire; a vibrotactile module having a body and a pin formed to project outward from an upper portion of the body; a magnet coupled and fixed to the body of the vibrotactile module, the magnet forming a magnetic field so as to vertically move through the interaction with the coil; a support coupled to the coil so as to fix the coil; and a housing for forming the exterior of the device, the housing having a hole formed on a predetermined position of an upper surface thereof, the position corresponding to the pin of the vibrotactile module.

[3] The pin-type vibrotactile device according to claim 1 or 2, wherein the vibrotactile module further includes a pin guide shaft formed in a lower portion of the body, the pin guide shaft being formed in the center direction of the coil.

[4] The pin-type vibrotactile device according to claim 3, wherein the vibrotactile module has a plate-shaped wing attached thereto, the plate-shaped wing strengthening the coupling between the magnet and the pin and maintaining the relative position between the pin and the magnet at a constant distance.

[5] The pin-type vibrotactile device according to claim 4, wherein the housing has a coil fixing board attached to the lower surface thereof, the coil fixing board fixing both ends of the conductive wire composing the coil such that both ends are connected to an external voltage along wiring lines. [6] The pin-type vibrotactile device according to claim 4 or 5, wherein the vibrotactile module has a spring attached thereto, the spring restoring the pin, which performs a vertical movement, to the former state.