WO2008007666A1

WO2008007666A1 - Bone conduction receiver

Info

Publication number: WO2008007666A1
Application number: PCT/JP2007/063730
Authority: WO
Inventors: Masahiko Fujita; Hideyuki Kawase; Yuji Nitobe; Katsuhiro Oono; Takeshi Tsuji; Takayuki Kanai
Original assignee: Nec Tokin Corporation; Ntt Docomo, Inc.
Priority date: 2006-07-10
Filing date: 2007-07-10
Publication date: 2008-01-17
Also published as: JP4861079B2; JP2008017398A

Abstract

Provided is a bone conduction receiver which can efficiently transmit outputted oscillation from a bone conduction speaker. A bone conduction receiver (1) is provided with a bone conduction speaker (10) for converting sound information to oscillation, and a case (2) for storing the bone conduction speaker (10). The bone conduction speaker (10) is provided with a multilayer columnar piezoelectric element (12) for generating oscillation in accordance with the sound information, and a pad (16), which protrudes from the case (2) for transmitting the oscillation generated by the multilayer columnar piezoelectric element (12) by abutting to the human head.

Description

Specification

Bone conduction receiver

Technical field

[0001] The present invention relates to a bone conduction receiver using a bone conduction speaker.

Background art

Conventionally, a bone conduction receiver has been developed as a hearing aid for bone conduction. In recent years, a bone conduction receiver is connected to an information device such as a mobile phone terminal and is applied as a man-machine interface device used as an input / output device for sound information (see, for example, Patent Document 1). Therefore, bone conduction receivers used as an interface for information devices are required to accurately transmit sound information from information devices such as mobile phones to their users. Furthermore, bone conduction receivers are required to reliably transmit user voices and operation information to information devices, and to be rich in portability as devices to be connected to portable information devices.

[0003] A bone conduction receiver using a bone conduction speaker has been proposed as one that meets these requirements. The bone conduction speaker vibrates the head of the human body and transmits the sound information to the user by transmitting the vibration to the auditory organ. In such a bone conduction receiver, sound information can be accurately transmitted to a person having a disorder in the transmission parts of the outer ear and the inner ear, as compared with an air conduction speaker in which sound information is transmitted by air vibration. Furthermore, since it does not use air conduction speed, it has high secrecy where sound leaks to the surroundings. Furthermore, since the pinna can be used in an open state and external sounds and alarm sounds can be heard, it has the advantage of being easy to obtain safety when used in crowded or noisy environments.

From these features, it is desirable to use a bone conduction speaker for the bone conduction receiver. This bone conduction receiver accurately transmits sound information, has good portability, and can be used well by many users such as healthy people and some people with hearing loss. Therefore, bone conduction receivers utilizing bone conduction spine force are suitable for input / output devices such as voice signals, and are being used by healthy people and people with hearing loss.

[0004] In recent years, everyone can accurately hear sound information from mobile phones etc., and be portable. A bone conduction speaker composed of a piezoelectric ceramic material has been proposed as a bone conduction speaker for a superior bone conduction receiver. A laminated columnar piezoelectric element is used for this bone conduction speaker, and the displacement in the longitudinal direction of the laminated columnar piezoelectric element is enlarged by the displacement amplification mechanism, and transmitted from the vibration output portion to the contacting head. In addition, a sufficiently large mass is placed on the fixed part of the amplification mechanism, and the displacement of the fixed part, which is the fulcrum of the magnifying mechanism, is suppressed as much as possible.

Yes

In particular, by adopting this bone conduction speaker as a bone conduction receiver, a large displacement can be secured in the vibration output part, and at the same time, the vibration of the fixed part can be suppressed small. Therefore, it is possible to further reduce the sound leakage of the bone conduction receiver. In addition, bone conduction speakers made of this piezoelectric ceramic material can be used for a longer time with the same battery consuming less power, and are more portable.

In the case where the laminated columnar piezoelectric element is incorporated into a portable apparatus such as a bone conduction receiver or a handset, the appropriate length of the laminated columnar piezoelectric element is about 10 mm or less because of the restriction on the product size. The standard amount of expansion and contraction of such a stacked columnar piezoelectric element of about 10 mm is about 2 μm to 3 μm, and it is difficult to obtain sufficient expansion and contraction for transmitting sound information.

Further, when this laminated columnar piezoelectric element is used as a power source and driven by the displacement amplification structure, an enlarged displacement can be obtained at the output end thereof. As a result, sound information sufficient for the user's perception can be transmitted, but sound information may not be transmitted sufficiently depending on the usage posture. In addition, in the case of a structure that amplifies the displacement of this stacked columnar piezoelectric element, it is not enough to make it smaller or lighter!

[0006] Furthermore, the conventional bone conduction receiver is a method in which the bone conduction speaker output portion is used by being in contact with the user's face. Therefore, in the propagation path of the vibration generated by the laminated columnar piezoelectric element of the bone conduction receiver, a structural loss of the bone conduction speaker and a loss due to the contact between the output part and the face occur. The structural loss of this bone conduction speaker can be reduced by making the mass of the bone conduction speaker fixed part sufficiently large. On the other hand, it is difficult to sufficiently reduce the loss associated with facial contact.

Patent Document 1: Japanese Unexamined Patent Application Publication No. 2006-86581 Disclosure of the invention

Problem that invention tries to solve

As described above, in the conventional bone conduction receiver, the output vibration of the bone conduction speaker can not be efficiently transmitted!

The present invention has been made in view of such problems, and it is an object of the present invention to provide a bone conduction receiver capable of efficiently transmitting the output vibration of the bone conduction speaker. Means to solve the problem

The bone conduction receiver according to the present invention is a bone conduction receiver including a bone conduction speaker for converting sound information into vibration, and a case for housing the bone conduction speaker, wherein the bone conduction speaker is The vibration generating unit generates vibration according to the sound information, and the case projects in a convex shape from the case, and transmits the vibration generated by the vibration generating unit to the human head while in contact with the human head. And a vibration transmission unit. In such a configuration, since the vibration transmitting portion projecting from the case reliably contacts the face, the output vibration of the bone conduction speaker can be efficiently transmitted.

Furthermore, the vibration transfer unit has a U-shaped shape, and the vibration generation unit is disposed in the vicinity of a surface different from the two surfaces facing each other in the vibration transfer unit, Vibration is generated between the two facing surfaces in accordance with the sound information. By this, it is possible to further vibrate the portion far from the vibration center of the vibration transmission unit to be vibrated by the vibration generation unit.

Furthermore, the convex peak portion protruding in the vibration transfer unit is disposed on the side farther from the position of the vibration generation unit than the center of the vibration transfer unit. As a result, since the peak part on the side away from the position of the vibration generating means can be vibrated more, the output vibration can be efficiently transmitted through this peak part.

Furthermore, the end of the vibration transfer unit that vibrates is disposed closer to the end surface than the center of the bone conduction receiver. As a result, the force S can be applied to further vibrate the vibrating end portion, so that the transmission efficiency of the output vibration can be enhanced.

Preferably, the vibration transfer unit includes a U-shaped frame, and a pad disposed on one of two opposing surfaces of the frame, the pad being in contact with the human head. Pat Is exposed in the state of protruding in a convex shape from the case. Thus, since the part in contact with the face is constituted by the pad, the contact with the face can be easily changed.

Preferably, the vibration generating unit is a laminated columnar piezoelectric element.

Preferably, the bone conduction speaker has a frame for housing the vibration generating unit, and a pad protruding in a convex shape from the case is fixed to an outer wall of the frame.

[0015] Preferably, the pad has a peak portion at a position most projecting from the case, and the peak portion is disposed near one end of the pad.

Preferably, the vibration generating unit is disposed near the other end of the pad.

On the other hand, a bone conduction receiver according to the present invention is a bone conduction receiver including a bone conduction speaker for converting sound information into vibration, and a case for housing the bone conduction speaker, wherein the bone conduction speaker is A U-shaped frame and vibration generating means disposed between two opposing faces of the frame and generating vibration between the two opposing faces according to the sound information; And a pad which is disposed on one of the two surfaces and which is exposed in a state where the case force also protrudes. In such a configuration, since the vibration transmitting portion projecting from the case is in contact with the face with certainty, it is possible to transmit the output vibration of the bone conduction speed efficiently.

Effect of the invention

According to the present invention, it is possible to provide a bone conduction receiver capable of efficiently transmitting the output vibration of the bone conduction speaker.

Brief description of the drawings

FIG. 1 is a schematic perspective view showing the appearance of a bone conduction receiver according to the present invention.

FIG. 2 is a schematic cross-sectional view of a bone conduction speaker in a bone conduction receiver according to the present invention.

FIG. 3 is a schematic cross-sectional view showing the mounting state of the bone conduction speaker in the bone conduction receiver according to the present invention.

FIG. 4 is a schematic cross-sectional view showing the state of contact between the bone conduction receiver according to the present invention and the head.

FIG. 5 is a schematic view showing an equivalent circuit model of the skin at the contact portion between the bone conduction receiver according to the present invention and the head.

[FIG. 6] The contact pressure component in the state of contact between the pad and the head of the bone conduction receiver according to the present invention It is a figure showing cloth.

FIG. 7A is a schematic view showing a usage posture of a bone conduction receiver according to the present invention and a head.

FIG. 7B is a schematic view showing a usage posture of the bone conduction receiver according to the present invention and the head.

FIG. 7C is a schematic view showing a usage posture of the bone conduction receiver according to the present invention and the head.

FIG. 8 is a schematic view showing a usage posture of the bone conduction receiver according to the present invention.

Explanation of sign

[0020] 1 ... bone conduction resino, 2 ... body case, 2a, 2b, 2c, 2d ... rib, 3 ... flip,

4 · · · connection cable, 4a ... connector, 10 · · · bone conduction speaker, 11 · · · frame,

11a: vibration output portion, lib: elastic portion, 11c: frame fixing portion, lid: vibration transmitting portion, 12: laminated columnar piezoelectric element, 13: base weight, 14: fixing portion, 15a, 15b ... Prepressing screw, 16 ... Pat, 16a ... Convex contact surface, 16b ... Peak, 18 ... Positioning plate,

21 ... call button, 22 ... volume switching switch, 23 --- LED, 24 ... hinge,

25a, 25b ... support member, 31 ... microphone

51 ... skull, 52 ... skin, 52a ... skin viscosity, 52b ... skin elasticity,

52c ... mass of skin

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The bone conduction receiver according to the present embodiment has a structure using a bone conduction speaker that converts sound information such as voice and music into vibration. The bone conduction speaker transmits the vibration obtained by converting the sound information to a part of the human head and transmits the vibration to the auditory organ to recognize the sound information.

Specifically, in the bone conduction receiver according to the present embodiment, the contact state between the bone conduction speaker and the face, the structure and the attachment method of the contact part of the bone conduction speaker, and the like are devised. By this device, a structure is realized in which the vibration generated by the laminated columnar piezoelectric element is more effectively transmitted to the auditory organ through the skin of the user regardless of the contact condition.

First, the overall configuration of the bone conduction receiver according to the present embodiment will be described with reference to FIG. FIG. 1 is a perspective view showing the configuration of the bone conduction receiver according to the present embodiment. As shown in FIG. 1, the bone conduction receiver 1 of the present embodiment includes a bone conduction speaker 10 and a telephone call speaker. It has a tongue 21, a volume change switch 22, an LED 23, a microphone 31, a body case 2, a flip 3, and a connection cable 4.

The bone conduction speaker 10 converts the electrical signal sent from the mobile phone via the connection cable 4 into mechanical vibration. The call button 21 controls the start of the call and the end of the call of the bone conduction receiver 1. The volume switching switch 22 adjusts the volume of the bone conduction speaker 10. The LED 23 reports an incoming call and the like by lighting and the like. The microphone 31 contains the user's sound. The main body case 2 houses the bone conduction speaker 10 of the bone conduction receiver 1, the call button 21, the volume change switch 22, the LED 23, and the like. Further, although not shown, a circuit board or the like for processing an electric signal from a mobile phone (not shown) or an operation signal of the call button 21 is also supported and housed inside the main body case 2. The flip 3 accommodates the microphone 31. The hinge 24 pivotally supports the flip 3 on the main body case 2. The connection cable 4 connects the mobile phone and the bone conduction receiver 1 by connecting the connector 4a to the mobile phone (not shown).

Subsequently, the structure of the bone conduction speaker 10 of the bone conduction receiver 1 of the present embodiment will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view showing the bone conduction speaker 10. As shown in FIG. 2, the bone conduction speaker 10 is assembled around a plate-like frame 11 having a U-shaped cross section. The frame 11 has a frame structure formed by three parts of a vibration output portion 11 b as a front surface, an elastic portion 1 lb as a side surface, and a frame fixing portion 11 c as a rear surface. In addition, the frame 11 is formed into a structure having a front surface, a side surface, and a back surface by pressing a metal plate member or the like. In the frame 11, a laminated columnar piezoelectric element 12 described later is accommodated.

In detail, the vibration output unit 11a for outputting the vibration is disposed on one side of the U-shaped frame 11, and the mass thereof is reduced as much as possible. At both side ends of the vibration output portion 11a, ribs for improving the rigidity of the vibration output portion 11a are provided downward. The flat elastic portion l ib supports the vibration output portion 11 a and the lower portion thereof is supported by the frame fixing portion 11 c. The frame fixing portion 11 c is disposed on the other side of the U-shaped frame 11 facing the vibration output portion 11 a. Both side ends of this frame fixing portion 11c On the other hand, a rib l lcc for improving the rigidity of the frame fixing portion 11 c is provided downward.

The laminated columnar piezoelectric element 12 has a characteristic of being displaced in the longitudinal direction, and is disposed between two opposing surfaces of the vibration output part 11a and the frame fixing part 11c. The upper end of the laminated columnar piezoelectric element 12 is in contact with the vibration output portion 11 a of the frame 11 and fixed so as not to be displaced by an adhesive (not shown). This adhesive (not shown) is made of a material having a lower modulus than that of the frame 11 and the laminated columnar piezoelectric element 12 and a lower modulus of Young's modulus !.

The lower end of the laminated columnar piezoelectric element 12 is in contact with the end face of the pressurizing screw 15b, and the pressurizing screw 15b is screwed into a screw hole provided in the frame fixing portion 11c. The four side surfaces of the lower end of the laminated columnar piezoelectric element 12 are regulated by the holes of the positioning plate 18, and are fixed by an adhesive (not shown) after pressurization. In addition, the input line of the laminated columnar piezoelectric element 12 passes through the lower part of the elastic portion l ib and is connected to a drive circuit board (not shown) housed in the main body case of the bone conduction receiver 1! .

The base weight 13 is provided in the inner space of the U-shaped frame 11 structure. Base weight

The reference numeral 13 sandwiches the positioning plate 18 with the frame fixing portion 11c, and in this state, the positioning plate 18 is fixed to the frame fixing portion 11c by a screw 15a. The fixing portion 14 is configured by the frame fixing portion l lc, the positioning plate 18, the base weight 13 and the screw 15 a. The total mass of the fixed portion 14 may be set at least twice or more, ideally 10 times or more as compared with the total mass of the vibration output portion 1 1 a and the pad 16. Also, the base weight 13 and the positioning plate 18 may be integrated into one part! / ,.

In the above-described basic structure, the pad 16 is provided on the vibration output unit 11a. The vibration output unit 11 a and the pad 16 constitute a vibration transmission unit l id that transmits the vibration generated by the laminated columnar piezoelectric element 12. The vibration output unit 11a and the pad 16 should ideally be a structure having a small mass and high rigidity as much as possible. The vibration output part 1 la and the pad 16 turn and vibrate on the basis of the rotation center of the vibration output part 11 a generated near the intersection of the vibration output part 11 a and the inertia part l ib. Therefore, the elastic portion l ib has a function of a hinge that rotatably supports the vibration output portion 11a. Furthermore, the elastic portion l ib has a function of generating a force for applying a pressure to the stacked columnar piezoelectric element 12, and in addition to these functions, it is possible to vibrate. It functions as a body spring. In addition, the frame fixing portion 11c can suppress the vibration of the fixing portion 14 by obtaining a larger mass as the entire fixing support portion together with the base weight 13 and the positioning plate 18 and the like.

When the bone conduction receiver 1 is used, the vibration output unit 11a contacts the face in the vicinity of the pinna and has a function of vibrating the contacting face by its vibration operation. Therefore, the vibration output part 11 a needs good contact with the face with respect to the feature of the elastic part l ib. Therefore, a pad 16 is provided on the upper surface of the vibration output portion 11a, and the pad 16 is made of a material having a low thermal conductivity, a small specific gravity, and a high rigidity. The pad 16 is fixed in a highly rigid state after positioning by the engagement of a hole for positioning and a boss. When the fixation between the vibration output unit 11a and the pad 16 is weak, a secondary vibration occurs between the two, and it is possible to transmit offensive sound information having a secondary vibration to the user. Here, the reason for using a material with a low thermal conductivity for the pad 16 is to reduce the “coldness” when the metal portion of the vibration output portion 11 a cools down and hits the face directly, such as in the early morning of winter. . The reason for using a material with a low specific gravity and high rigidity is to increase the amplitude by reducing the mass of the vibrating part, and to prevent the occurrence of secondary vibration in the vibration output part 11a by the high rigidity. is there.

Subsequently, the attachment state of the bone conduction speaker 10 to the bone conduction receiver 1 will be described with reference to FIG. FIG. 3 is a cross-sectional view schematically showing the bone conduction speaker 10 in an attached state. As shown in FIG. 3, the bone conduction speaker 10 is provided with ribs 2a, 2b, 2c, It is held by 2d. The support members 25a and 25b are made of a visco-elastic material and have a function of absorbing the vibration of the fixed portion 14. Specifically, when a vibration is generated by the bone conduction speaker 10, the vibration is transmitted from the vibration output unit 11a to the head of the user via the pad 16 and transmitted. The fixing portion 14 vibrates due to a reaction force against the vibration (working force) transmitted to the head, and the support members 25a and 25b absorb the vibration. Here, the viscoelastic material is a member having both viscosity and elasticity, and indicates, for example, a silicon rubber member having a hardness of 5 degrees or less, a gel-like material having silicon as a base material, and the like. A pad 16 is attached to the vibration output unit 11 a (front surface) of the bone conduction speaker 10. The putt 16 is very important as an interface for transmitting vibration to the user. In the bone conduction receiver 1, the pad 16 of the bone conduction speaker 10 is in direct contact with the skin of the user's head, and transmits the vibration of the vibration output part 1 la to the user's auditory organ through the skin of the contact part. The pad 16 is made of a material having a low thermal conductivity and a low specific gravity and a high rigidity. On the other hand, the head has a structure in which the soft skin 52 covers the top of the skull 51. As shown in FIG. 4, in the contact structure of the pad 16 and the head, a hard pad 16, a soft skin 52 and a hard skull 51 form a sandwich structure. The notch 16 is a projecting member from the case 2. The pad 16 has a peak at a position most projecting from the case 2. The peak portion is disposed near one end of the putt 16. The stacked columnar piezoelectric element 12 is disposed near the other end of the pad 16.

[0031] In this sandwich structure, the skin 52 shows a soft part existing between the epidermis and the skull 51 and has softness and its mass. The softness of the skin 52 is physically viscous and can be broken into viscosity and elasticity. A circuit model equivalent to this sandwich structure is shown in FIG.

As shown in FIG. 5, in the signal (vibration) transmission system from the pad 16 to the skull 51, the contact point a corresponds to the notch 16 and is a contact point to which a signal is input. The transmission system elements of the skin 52 connected to this contact point a are the viscosity 52a of the skin, the elasticity 52b of the skin, and the mass 52c of the skin. The contact point b is a contact point corresponding to the skull 51 and serving as a signal output. Also to this contact point b, skin viscosity 52a, skin elasticity 52b, and skin mass 52c are connected. In this equivalent circuit model, in order to transmit the signal vibration more largely, that is, to transmit it without attenuation, it is necessary to reduce the impedance of the transmission system. Specifically, the viscosity 52a and the mass 52c are reduced, and the elasticity 52b is increased.

The reduction of the impedance in this equivalent circuit model will be specifically described using the bone conduction receiver 1 in contact with the head with reference to FIG. As shown in FIG. 4, when the pad 16 comes in contact with the skin 52, the pad 16 forms a convex surface so that the contact surface 16a of the pad 16 bites into the skin 52 with which it abuts. At the time of use, the user applies the bone conduction receiver 1 to the face skin 52 in the vicinity of the pinnae 16 of the bone conduction receiver 1. Then, the convex formed by the putt 16 The contact surface 16a is slightly pushed into the skin 52 of the user's face, and the user's skin 52 forms a recess along the surface of the convex pad 16. By this series of operations, the convex contact surface 16 a of the pad 16 and the concave portion of the skin 52 closely fit.

[0033] FIG. 6 shows the pressure distribution between the mated pad 16 and the skin 52. In the pad 16, the peak 16b of the convex contact surface 16a is pushed most into the skin 52, and the contact pressure is the highest (pressure center). In the high pressure part (center of pressure) due to the contact, the contact pressure causes the soft skin 52 to spread laterally, and a part of it moves spatially to the periphery. At the same time, the portion with low peripheral contact force moves the skin to a lower pressure non-contact portion by the contact force. As a result, the skin 52 receives the highest contact pressure in the portion (center of pressure) where the convex abutment surface 16a of the pad 16 is most invading, and the contact pressure decreases toward the periphery of the most intruded portion Do.

The contact portion between the pad 16 and the skin 52 will be described in more detail in the equivalent circuit model shown in FIG.

The skin 52 in the high pressure portion is pressed and compressed most in the direction of the skull 51 in the portion (center of pressure) corresponding to the peak 16 b of the convex abutment surface 16 a in the pad 16. With this compression, the pressure-centered skin tissue receives a higher pressure than the surrounding area, and the soft skin tissue spreads laterally. At the same time, the fluid (body fluid) in the skin tissue moves to the periphery. This results in the largest reduction in skin tissue volume.

Physically, the ratio of the liquid etc. is reduced, so the mass and viscosity are reduced, and the skin tissue becomes hard, so the elasticity becomes large. In the equivalent circuit model shown in Fig. 5, the impedance of the transfer system is reduced and the transferability is improved. That is, in the portion where the contact pressure is increased by the contact between the pad 16 and the skin 52, the vibration is more effectively transmitted, and the vibration is most effectively transmitted near the pressure center.

The area around the pressure center is lower in contact pressure than the pressure center, so there is less mass and less increase in elasticity, but in this area it is sufficient compared to the non-contact area. Large changes occur and vibrations are transmitted. From the above-mentioned characteristics of the skin, in order to effectively transmit the vibration to the perception part of the user by contact, it is desirable to adopt a contact structure that raises the contact pressure in the range where the user does not feel uncomfortable. In the bone conduction speaker 10 of the bone conduction receiver 1 according to the present embodiment, as shown in FIG. 2, the laminated columnar piezoelectric element 12 is inserted into a frame formed in a U-shape to form a laminated columnar piezoelectric element. It has a structure in which the displacement of element 12 is expanded by applying the “lever principle”. The displacement of the laminated columnar piezoelectric element 12 causes the vibration output portion 11a to rotate and vibrate with respect to the rotation center of the vibration output portion 11a generated near the intersection of the vibration output portion 11a and the elastic portion l ib.

The amplification degree of the displacement of the vibration output unit 11a is increased on the vibration output unit 11a as it deviates from the reference of the rotation. On the other hand, the displacement of the vibration output part 11a becomes larger than the displacement of the laminated columnar piezoelectric element 12 alone at a position distant from the laminated columnar piezoelectric element 12, and the vibration output part 11a most distant from the rotation center Maximum at the tip of the

As described above, in the bone conduction speaker 10 according to the present embodiment, the peak 16 b of the convex contact surface 16 a serving as the pressure center of the pad 16 is from the central portion in the longitudinal direction of the pad 16 as viewed from the rotation center. , Is located on the tip 16c side. By adopting this structure, a large displacement can be secured at the peak 16 b of the convex contact surface 16 a of the notch 16. At the same time, the effect of the convex shape of the notch 16 can be utilized, so that the vibration of the laminated columnar piezoelectric element 12 can be effectively transmitted to the user's perception part.

Furthermore, in the bone conduction speaker 10 of the bone conduction receiver 1 according to the present embodiment, as shown in FIG. 3, the rotation center of the vibration output unit 11 a is disposed on the center side of the bone conduction receiver 1. At the same time, the tip of the vibration output part 1 la that is displaced (swinged) by a greater amount than during operation of the vibration output part 11 a is disposed on the tip 20 side of the main body case 2 of the bone conduction receiver 1. Therefore, the vibration in the bone conduction speaker 10 can be more effectively transmitted to the user's perception part.

The usage posture of the bone conduction receiver 1 according to the present embodiment will be described with reference to FIGS. 7A to 7C.

As shown in FIG. 7A, the ideal usage posture of the bone conduction receiver 1 of the present embodiment is a case where it is disposed substantially parallel to the face 52a. It is assumed that the usage posture of the bone conduction receiver 1, particularly the contact angle with respect to the face, varies greatly depending on the user while the force. Specifically, first, there is an ideal abutment state in which the bone conduction receiver 1 and the face 52a shown in FIG. 7A are in contact with each other substantially in parallel. From this state, as shown in FIG. It is assumed that the conductive receiver 1 abuts with a slight inclination. Furthermore, as shown in FIG. 7C, it is assumed that the face 52a and the bone conduction receiver 1 abut against each other with a large inclination.

As described above, there are various contact states that differ depending on the user. In the bone conduction receiver 1 according to the present embodiment, the peak 16b of the convex contact surface 16a of the pad 16 is disposed on the tip 20 side of the bone conduction receiver 1 from the central portion of the pad portion 16. As a result, stable contact between the peak 16b of the convex contact surface 16a of the pad 16 and the user's face can be secured, and the vibration can be reliably transmitted to the user's perception unit.

Finally, use of the bone conduction receiver 1 according to the present embodiment will be described with reference to FIG. FIG. 8 is a schematic view showing a utilization state of the bone conduction receiver 1 according to the present embodiment. Here, description will be made with reference to FIG. 1 as appropriate.

As shown in FIG. 8, when using the bone conduction receiver 1, it is convenient to connect the connection cable 4 to a portable telephone (not shown) in advance. In this state, for example, when the mobile phone receives a call from another phone, the user opens the flip 3 and presses the call button 21. Then, an electrical signal of sound information such as a call voice is transmitted from the mobile phone (not shown) connected to the bone conduction receiver 1 to the circuit board in the body case 2 of the bone conduction receiver 1 via the connection cable 4. . This electric signal is applied as an alternating current signal from the circuit board to the laminated columnar piezoelectric element 12 shown in FIG. 2 through an input line. The stacked columnar piezoelectric element 12 performs expansion / contraction fluctuation (displacement) corresponding to the signal in the longitudinal axis direction by the electric signal.

The vibration output unit 11 a and the frame fixing unit 11 c of the frame 11 continue displacement with each other due to the bending deformation of the elastic portion l ib due to the expansion / contraction fluctuation of the laminated columnar piezoelectric element 12. As shown in FIG. 2, the bone conduction speaker 10 according to the present embodiment incorporates a structure utilizing the principle of leverage. Therefore, even if the amount of expansion and contraction of the laminated columnar piezoelectric element 12 alone is about 2 m to 3 m, the displacement of the pad 16 attached to the vibration output part 11a is expanded by the designed predetermined value. As a result, sufficient vibration is transmitted to the user's perception unit, and it is recognized as sound information.

Also, at this time, as shown in FIG. 7C, the user's power S, the bone conduction receiver 1 is placed on the head of the user. It is assumed that contact is made in a state of being greatly inclined. Also in this case, the contact surface 16a of the pad 16 fixed to the vibration output part 11a of the bone conduction receiver 1 is a convex surface having a peak 16b on the tip side which rotates with respect to the rotation center of the pad 16 Form a shape. Therefore, even if the bone conduction receiver 1 abuts on the head of the user with a large inclination, the vibration is effectively transmitted to the user.

When the bone conduction speaker 10 of the bone conduction receiver 1 according to the present embodiment operates, the vibration output unit 11a and the frame fixing unit 11c mutually perform displacement vibration movement in the direction in which the tip end side opens and closes. At this time, the mass of the vibration output portion 11a and the pad 16 is sufficiently smaller than the total mass of the fixing portion 14 in which the positioning plate 18, the base weight 13, the frame fixing portion 11c, the screw 15 and the like are integrated. Therefore, the expansion and contraction displacement generated in the stacked columnar piezoelectric element 12 mainly displaces the vibration output portion 11a. In other words, the vibration generated in the laminated columnar piezoelectric element 12 can drive the vibration output unit 11a in a concentrated manner to transmit a signal to the user.

Further, since the mass of the fixing portion 14 which is the side supported by the main body case 2 is large, the vibration generated in the laminated columnar piezoelectric element 12 is mainly emitted from the vibration output portion 11a, and hence the fixing is performed. Vibration of part 14 is small. Furthermore, a support member 25 made of a visco-elastic material is provided between the frame fixing portion 11 c and the case 2. Therefore, the vibration generated in the laminated columnar piezoelectric element 12 and transmitted to the frame fixing portion 11 c is attenuated by the support member 25 and then transmitted to the main body case 2. Therefore, the vibration transmitted to the main body case 2 can reduce the sound volume leaking from the small main body case 2 to the outside air, particularly to the surrounding air, to a very small level S which does not matter. This can prevent sound leakage. Also, this sound leakage reduction effect corresponds to the total mass of the fixed part 14 and is set in consideration of the size and weight as a force product that has the effect as the mass is larger.

As described above, according to the bone conduction receiver 1 according to the present embodiment, even if the stacked columnar piezoelectric element 12 with a small amount of displacement is used, the generated vibration is concentrated to the vibration output unit 1 a. That ability S can. As a result, the vibration of the laminated columnar piezoelectric element 12 can be efficiently transmitted to the head of the user, and the necessary volume can be sufficiently secured.

Furthermore, the amount of vibration transmission to the case that causes increased sound leakage has a relatively simple structure. Therefore, it can be reduced and the necessary level of sound leakage reduction effect can be obtained without adopting a special sound leakage containment structure. Also, by disposing the tip of the vibration output unit 11a on the tip 20 side of the bone conduction receiver 1, it is possible to reduce the influence of the user's usage posture.

As described above, according to the present embodiment, it is possible to improve the loss caused by contact with the face, and rationalize the output vibration of the bone conduction speaker having the displacement amplification structure to the user's hearing. It can be transmitted. Therefore, in the bone conduction receiver 1 according to the present invention, as compared to other bone conduction speakers using the same laminated type columnar piezoelectric element, a larger vibration can be transmitted to the user's auditory organ, which is easier to use. Conducted receivers can be realized. Industrial applicability

The present invention is applicable to a bone conduction receiver using a bone conduction speaker.

Claims

The scope of the claims

[1] a bone conduction speaker that converts sound information into vibration;

A bone conduction receiver including the case for housing the bone conduction speaker, wherein the bone conduction speaker is

A vibration generating unit that generates a vibration according to the sound information;

A bone conduction receiver comprising: a vibration transmitting portion projecting in a convex shape from the case and transmitting vibration generated by the vibration generating portion to the human head in a state of being in contact with the human head.

[2] The vibration transfer unit has a U-like shape,

The vibration generating unit is disposed between two opposing surfaces of the vibration transmitting unit, and is disposed near a surface different from the two surfaces, and vibrates between the two opposing surfaces according to the sound information. The bone conduction receiver according to claim 1, characterized in that

[3] The convex peak portion which protrudes in the vibration transmitting portion is disposed on the side farther from the position of the vibration generating portion than the center of the vibration transmitting portion. Bone conduction receiver as described.

[4] The bone conduction receiver according to any one of claims 1 to 3, wherein the vibration generating unit is disposed closer to the end face than the center of the bone conduction receiver.

[5] The vibration transmission unit is

U-shaped frame,

And a pad disposed on one of two opposing surfaces of the frame and abutting on the human head;

The bone conduction receiver according to any one of claims 1 to 4, wherein the pad is exposed in a state of protruding in a convex shape from the case.

[6] The bone conduction receiver according to any one of claims 1 to 5, wherein an end portion of the vibration transmitting portion that vibrates is a laminated columnar piezoelectric element.

[7] The bone conduction speaker has a frame for housing the vibration generating unit,

The bone conduction receiver according to claim 1, wherein a pad protruding in a convex shape from the case is fixed to an outer wall of the frame.

[8] The putt has a peak portion located at the most projecting position from the case, The bone conduction receiver according to claim 1, wherein the peak portion is provided near one end of the pat.

[9] The bone conduction receiver according to claim 8, wherein the vibration generating unit is disposed near the other end of the pat.

[10] a bone conduction speaker that converts sound information into vibration;

U-shaped frame,

A vibration generating unit disposed between two facing surfaces of the frame and generating a vibration between the two facing surfaces according to the sound information;

A bone conduction receiver comprising: a pad disposed on one of two opposing faces of the frame and exposed in a projecting state from the case.