WO2002025989A1

WO2002025989A1 - Subminiature bone conduction speaker

Info

Publication number: WO2002025989A1
Application number: PCT/KR2000/001035
Authority: WO
Inventors: Sung-Chan Han
Original assignee: Han Sung Chan
Priority date: 2000-09-21
Filing date: 2000-09-21
Publication date: 2002-03-28
Also published as: AU2000274551A1

Abstract

The present invention relates to a subminiature bone conduction speaker which vibrates bones around human skull directly and stimulates auditory nerves through bone conduction in order to help sound to be heard. Vibrations are transmitted to a part of human head and its resulting vibration power makes sound heard through the bone conduction. The bone conduction speaker of the present invention can be applied to various fields such as mobile phone, wireless phone, earring-type mobile phone, telephone and the like since it can be made a subminiature easily and improves conventional bone conduction speakers. In addition, it keeps communication private by reducing sound discharges toward outside.

Description

SUBMINIATURE BONE CONDUCTION SPEAKER

TECHNICAL FIELD

The present invention relates to a subminiature bone conduction speaker.

More particularly, the present invention relates to a bone conduction speaker which vibrates bones around human skull directly and stimulates auditory nerves through bone conduction in order to help sound to be heard. The bone conduction speaker of the present invention can be applied to various fields such as mobile phone, wireless phone, earring-type mobile phone, telephone and the like since it improves conventional bone conduction speakers and can be subminiaturized easily. In addition, it keeps communication private by reducing sound discharges toward outside.

BACKGROUND ART

Generally, all information existing around us is delivered in a form of waves. For example, sound heard through ears, light entering into eyes, electromagnetic waves received by television and radio are transferred from sources to receivers by use of wave movement, without the movement of material between the two points .

Sound heard through ears is a wave which is made of vibrations in objects and a kinetic energy with a peculiar form which is generated by the movement of atoms in a regular pattern. Various sound equipments available in everyday lives exploit the kinetic energy of electrons when currents flow along the wire. The kinetic energy of electrons is a kind of electric energy and makes sounds in speakers . We can hear the sound of speaker when air vibrates the eardrum through the molecular movement. Sound enters external auditory meatus (EAC) , that is through ear pore, and vibrates the eardrum. Then cells of internal ear inside the eardrum are stimulated and the sound is transmitted to brain so as to be heard. Sound that humans can hear is in the range of 20 ~ 20,000 Hz and sound suitable for human audition is in the range of 125 ~ 8,000 Hz. Conversational sounds suitable for human dialogues are mainly in the frequency range of 500 ~ 2,000 Hz. Normal human beings can hear all the waves in between these frequencies but hearing-impaired people can not hear all the sounds or certain sounds with specific frequencies very well.

Recently, bone conduction telephones have been developed to help hearing-impaired or old people to communicate like normal people. The bone conduction telephone enables hearing-impaired or old people to speak without external auxiliary equipment by using bone conduction as a part of auditory sense. Namely, ordinary telephones transform electric signals into sound signals through receivers consisting of speakers in order to hear it through ears. Meanwhile, the bone conduction telephone exploits an unfamiliar medical concept - bone conduction auditory sense - which enables hearing-impaired person damaged on external ear and middle ear to hear by^' ringing bones around auricula. When the bone conduction auditory sense is used, surrounding noises are removed effectively. Therefore, in noisy environment such as market, construction place and so on, general public can communicate excellently with these telephones as well .

Korean Patent Publication No. 96-7406 have disclosed that the bone conduction waver which enables deafness patient hear through auditory sense by bone conduction and also makes normal human beings hear sound signals through air way. Particularly, the bone conduction waver is equipped to fix a mastoid stimulating cranium directly on the upper end of voice coil and to vibrate a diaphragm by the interaction between fixed magnetic bar and magnetic field formed by the voice coil .

However, the bone conduction waver has some disadvantages as follows. Possibly, the leader line of voice coil is prone to be cut by oscillations. Moreover, in the case of reducing the size of the waver, the ratio that cuts occur increases since the miniaturization is restricted by the interference of leader lines and then the power that the speaker generates is weaken. Besides, the bone conduction waver cannot keep communicational securities when used in correspondence with terminal equipments because it discharges sound to outside on account of structural problems .

DISCLOSURE OF INVENTION

To overcome the foregoing and other disadvantages, the inventors of the present invention have tried to develop new bone conduction speaker.

It is an object of the present invention to provide a subminiature bone conduction speaker which vibrates bones around human skull directly and stimulates audition nerves through the bone conduction in order to help sound heard.

It is another object of the present invention to provide a bone conduction speaker which has disparable features from conventional bone conduction oscillators. Concretely, the present invention provides the bone conduction speaker which has a structure that a voice coil is fixed on a base plate; a magnetic circuit oscillating upward and downward is installed; and a mastoid for transmitting sound vibrations to outside is set on the upper end of the magnetic circuit. Therefore, the bone conduction speaker of the present invention can be made to a subminiature and thus applied to various fields usefully. In addition, it can keep the communication security effectively since it seldom discharges sound to outside.

Further objects and advantages of the present invention will appear hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which;

FIG. 1 depicts a plane figure of the subminiature bone conduction speaker described in Preferred Embodiment of the present invention; and

FIG. 2 depicts a sectional view of FIG. 1 described across the line II - II.

***** Explanation of symbols in the figures *****

10: bone conduction speaker 11: electrode terminal plate 12 : frame

1 : base plate

16: mastoid

18: bushing 20: damper

22: yoke

24 : magnetic bar

26: overhead plate

28: adaptor 30: voice coil

32: eyelet S : inner space G: space

BEST MODE FOR CARRYING OUT THE INVENTION

In order to accomplish the objects of the present invention, the present invention provide a bone conduction speaker which comprises as follows: a frame which limits a certain space and is composed of an overhead layer, a side layer, a bottom layer and a shoulder forming stairs in a radiational type between said overhead layer and said side layer; a vibration contact part which is installed in a central aperture part, protruded to upside against said overhead layer and touches a part of human head directly; a bushing which is arranged vertically on the inner surface of said shoulder and on the overhead surface of said bottom layer and inserted to the interior part of said side layer; a damper which is arranged between the inner surface of said shoulder and the overhead surface of said bushing with its radiated ends, supported with said bushing, and reduces oscillations or sound amplitude to be vibrated stably; a yoke which is arranged within said space, composed of a body part inserted into an assembling aperture formed in the center of said damper and one body with said body part, equipped with an extension part elongated downward, supports the other end of said damper through said shoulder formed in said body part and concentrates magnetic flux; a magnetic bar which is arranged at the inside of said radiated region in said extension part and has a close contact between its overhead surface and the bottom surface of said body part; an overhead plate which is arranged at the inside of said extension part, composed of a magnetic circuit with said yoke and said magnetic bar and has a close contact between its overhead surface and the bottom surface of said magnetic bar; a voice coil which is arranged in a space constructed with said overhead plate, both ends of said magnetic bar and the inner surface of said extension part and fixes its lower end on said bottom layer; and an adaptor which is arranged in between the uppest surface of said yoke and the inner surface of said vibration contact part and supports said vibration contact part for the fixation.

As demonstrated above, the bone conduction speaker of the present invention is composed of several components. Concretely, the bone conduction speaker fixes the voice coil onto the bottom layer of the frame, makes the magnetic circuit vibrating upward and downward among the yoke, the magnetic bar and the overhead plate and is installed with the vibration contact part on the upper end of the magnetic circuit for transmitting sound oscillations to outside. Hence, it can vibrate bones around human skull directly, stimulate audition nerves through the bone conduction and finally makes sound heard. Hereinafter, the subminiature bone conduction speaker of the present invention will be more clearly described referring to accompanying drawings .

FIG. 1 depicts a plane figure of subminiature bone conduction speaker described in Preferred Embodiment of the present invention; and FIG. 2 depicts a sectional view of FIG. 1 illustrated across the line II - II. As shown in FIG. 1 and FIG. 2, the subminiature bone conduction speaker (10) of the present invention has a cylinder shape preferably as depicted in

Preferred Embodiment. It contains the frame (12) which forms the side layer and the overhead layer of the bone conduction speaker (10) and is fixed up with the circular base plate (14) on its open inner bottom side

(12) . On the contrary, the bottom layer of the frame

(12) can be made of the base plate (14) . Thus, the frame (12) and the base plate (14) limit a certain space.

On the outside of the bottom surface in the base plate (14) , the electrode terminal plate (11) is installed in order to receive licensed currents from the external providers of electric power (not depicted) .

One end of the coil (13) is fixed on the electrode terminal plate (11) by brazing, the coil (13) is extended to the inside of the bone conduction speaker

(10) through the base plate (14) and the other end of the coil (13) extended above is connected with the lower end of the voice coil (30) which is fixed and stood on the base plate (14) within the bone conduction speaker (10) . Once currents are licensed from external providers of electric power to the electrode terminal plate (11) and provided from the electrode terminal plate (11) to the voice coil (30) through the coil (13) , the voice coil (30) induces changes of magnetic system by using electric energy of voice signals.

On the circular aperture part (not noted symbols of figure) formed in the center of the overhead layer (12a) of the frame (12) , the mastoid (16) , a vibration contact part keeping contact directly with a part of human head, is fixed and installed. The mastoid (16) is protruded upward against the overhead layer (12a) of the frame (12) and makes a smoothly curved shape with certain curvature, considering the contact with the part of human head.

In the border line of the overhead layer (12a) of the frame (12) and the side layer (12c) , the shoulder (12b) is arranged to form stairs in a radiational style and on the inner surface of the shoulder (12b) and the overhead surface of the base plate (14) within the bone conduction speaker (10) , the bushing (18) is installed vertically and the damper (20) horizontally. The bushing (18) is a thin cylinder which is inserted to the inner surface of the side layer (12c) and sustains oscillations of the damper (20) stably when the bone conduction speaker (10) works. The outer surface of the bushing (18) has a close contact with the inner surface of the side layer (12c) of the frame. The bushing (18) supports radiational ends of the damper (20) which is arranged toward a cross direction within the bone conduction speaker (10) . The damper (20) reduces the amplitude of oscillations and sounds by scattering energies and the other end of the damper (20) is supported by the shoulder (22b) of the yoke (22) situated in the center of the bone conduction speaker (10) . The yoke (22) is a case that can concentrate magnetic flux in the bone conduction speaker (10) and made of cast iron and cast steel. The yoke (22) is arranged in the inner space (S) which is determined by the base plate (14) , the bushing (18) and the damper (20) . In the inner space (S) , the yoke (22) is composed of a body part (22a) inserted into the assembling aperture (not noted a symbpl of figure) formed in the center of damper (20) and one body with the body part (22a) and has the extension part (22d) elongated downward.

On the inside of the radiation in the extension part (22d) of the yoke (22) , the circular magnetic bar

(24) and the overhead plate (26) are placed. The magnetic bar (24) and the overhead plate (26) comprise a magnetic circuit with the yoke (22) . The overhead surface of the magnetic, bar (24) has a close contact with the bottom surface of the body part (22a) in the yoke (22) and the bottom surface of the magnetic bar (24) has a close contact with the overhead surface of the overhead plate (26) . In the space (G) formed with among the overhead plate (26) , both ends of the magnetic bar (24) and the inside of the extension part in the yoke (22), the voice coil (30) is placed as illustrated above.

On the other hand, the adapter (28) is installed in between the uppest surface (22c) of the yoke (22) and the inside of the mastoid (16) in order to fix and support the mastoid (16) . In the bone conduction speaker (10), the adaptor (28), the yoke (22), the magnetic bar (24) and the overhead plate (26) are arranged vertically and orderly and crossing their centers, the assembling apertures (not noted symbols of figure) are perforated. Then the eyelet (32) with a tube shape is inserted as an iron decoration, joined by pushing both ends of the eyelet (32) and then fixed to one body.

PREFERRED EMBODIMENT

Practical and presently preferred embodiments of the present invention are illustrated as shown in the following Preferred Embodiment.

However, it will be appreciated that those skilled in the art, in consideration of this disclosure, may make modifications and improvements within the scope of the present invention.

Hereinafter, the present invention will describe the subminiature bone conduction speaker (10) in detail at the viewpoint of operations.

Once currents are licensed from external providers of electric power to the electrode terminal plate (11) and provided along the coil (13) from the electrode terminal plate (11) to the voice coil (30) , the voice coil (30) induces changes of magnetic system by using electric energy of voice signals. That is, if currents are licensed toward the voice coil (30) , magnetic field is generated between the magnetic bar (24) and the voice coil (30) which is arranged in the space (G) of magnetic circuit consisting of the overhead plate (26) , the magnetic bar (24) and the yoke (22) . As a result, Fleming's left hand principle comes into existence. In that case, the voice coil (30) is fixed and the magnetic field which is built up cooperatively among the voice coil (30) , the overhead plate (26) , the magnetic bar (24) and the yoke (22) works for attractive force and repulsive force. Then, the magnetic circuit which is composed of the overhead plate (26) , the magnetic bar (24) and the yoke (22) and jointed to one body vibrates upward and downward. At this point, the damper (20) installed in the upper end of yoke (22) prevents free oscillations of the magnetic circuit, which makes the oscillations sustained constantly. This vibration is transmitted through the mastoid (16) to a part of human head touched with the mastoid (16) . As a result, the vibration power is obtained to help sound heard through the bone conduction.

INDUSTRIAL APPLICABILITY

As demonstrated above, the subminiature bone conduction speaker of the present invention has distinct features from conventional bone conduction oscillators as described preferably in Preferred

Embodiment. It fixes the voice coil (30) onto the base plate (14) , makes a magnetic circuit vibrating upward and downward among the yoke (22) , the magnetic bar

(24) and the overhead plate (26) and is installed with the mastoid (16) on the upper end of the magnetic circuit for transmitting sound oscillations to outside. Thus, the subminiature bone conduction speaker can vibrate bones around human skull directly and stimulates auditory nerves through bone conduction in order to help sound heard for hearing-impaired people as well as normal human beings. In addition, the bone conduction speaker of the present invention can be applied to various fields such as mobile phone, wireless phone, earring-type mobile phone, telephone and the like since it can be made a subminiature easily and keeps communication private by reducing sound discharges toward outside. Those skilled in the art will appreciate that the conceptions and specific embodiments disclosed in the foregoing description ay be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. Those skilled in the art will also appreciate that such equivalent embodiments do not depart from the scope of the invention as set forth in the appended claims.

Claims

What is claimed is:

1. A bone conduction speaker which comprises: a frame which is composed of an overhead layer, a side layer, a bottom layer and a shoulder forming stairs in a radiational type between said overhead layer and said side layer and limits a certain space; a vibration contact part which is installed in a central aperture part, protruded to upside against said overhead layer and touches a part of human head directly; a bushing which is arranged vertically on the inner surface of said shoulder and the overhead surface of said bottom layer and inserted to the inner surface of said side layer; a damper which is arranged between the inner surface of said shoulder and the overhead surface of said bushing with its radiated ends, is supported with said bushing, vibrates stably and reduces oscillations or sound amplitude; a yoke which is arranged within said space, makes one body with a body part inserted into an assembling aperture formed in the center of said damper, is equipped with an extension part elongated downward, supports the other end of said damper through said shoulder formed in said body part and concentrates magnetic flux; a magnetic bar which is arranged inside of radiated region in said extension part and has a close contact between its overhead surface and the bottom surface of said body part; an overhead plate which is arranged inside of said extension part, composed of a magnetic circuit with said yoke and said magnetic bar and has a close contact between its overhead surface and the bottom surface of said magnetic bar; and a voice coil which is arranged in a space constructed with said overhead plate and both ends of said magnetic bar and the inner surface of said extension part and fixes its lower end on said bottom layer.

2. The bone conduction speaker according to claim 1, including an adaptor which is arranged in between the uppest surface of said yoke and the inner surface of said vibration contact part and supports said vibration contact part for the fixation.

3. The bone conduction speaker according to claim 2, in which an electrode terminal is made onto the outer bottom surface of said bottom layer in order to receive currents from external providers of electric power, one end of coil is brazed in said electrode terminal, said coil is extended to inside of said bone conduction speaker across said bottom layer, and the other end of said coil is connected to the lower end of said voice coil.

4. The bone conduction speaker according to claim 3, in which: said adaptor, said yoke, said magnetic bar and said overhead plate are arranged vertically and orderly, assembling apertures are perforated crossing their centers respectively, and an eyelet with a tube shape is inserted as an iron decoration and joined by pushing both ends of said eyelet to be fixed to one body;

Once currents are licensed from external providers of electric power to said electrode terminal and provided along the coil (13) to said voice coil, in the fixed state of said voice coil, magnetic field built up cooperatively among said voice coil, said overhead plate, said magnetic bar and said yoke works as an attractive force and a repulsive force, said magnetic circuit vibrates upward and downward and said damper represses free oscillations of said magnetic circuit to sustain them consistently; and said oscillations are transmitted to a part of human head touched with said vibration contact part through said vibration contact part.