WO2021128654A1

WO2021128654A1 - Bone conduction loudspeaker for ultrasonic and electroacoustic system

Info

Publication number: WO2021128654A1
Application number: PCT/CN2020/084207
Authority: WO
Inventors: 吕志伟; 吕通; 郑明华
Original assignee: 深圳市睿德龙科技有限公司
Priority date: 2019-12-24
Filing date: 2020-04-10
Publication date: 2021-07-01

Abstract

The present invention provides a bone conduction loudspeaker for an ultrasonic and electroacoustic system, comprising an acoustic transducer and an acoustic coupler. The acoustic transducer is configured to convert an electric signal into acoustic vibration energy; the acoustic coupler is composed of a kinetic energy output connecting rod 106, a positioning and elastic supporting piece 107, a kinetic energy balancing gasket 108, a coupler damping elastic piece 109, a coupler resonance elastic piece 110, and an acoustic wave loading plate. In the present invention, the transducer and the acoustic coupler are designed separately; the transducer focuses on improving energy efficiency and reducing acoustic wave distortion; the acoustic coupler of the present invention focuses on transmission efficiency and frequency response control. According to the solid-state transmission acoustic coupler of the present invention, the transmission efficiency of a bone conduction earphone and coupling between an acoustic wave solid-solid object and a solid-solid object is greatly improved, and the conversion efficiency can be greatly improved.

Description

Bone conduction speakers for ultrasonic and electroacoustic systems

Technical field

The present invention relates to the field of bone conduction technology, in particular to a bone conduction speaker used in ultrasonic and electroacoustic systems.

Background technique

The prior art bone conduction loudspeaker closely integrates the transducer device and the sound coupler into a whole. Such a design, in the transmission of sound quality and kinetic energy, it is difficult to take into account various technical instructions, and it has the disadvantage of affecting the whole body.

The structure of the existing bone conduction loudspeaker is shown in Figure 1. It includes a housing, a transducer, a sound coupler, a first vibration plate, and a panel; the energy conversion device is arranged in the housing; the energy conversion device passes through the first vibration plate Suspension connection with the shell; the panel is connected with the transducer device and vibrates under the drive of the transducer device. The panel protrudes from the shell, and the edge of the shell is provided with a border. There is a height difference between the border and the panel, and the skin acts on it. The force on the panel reduces the distance between the panel and the surrounding edge. When the pressure between the bone conduction speaker and the user is greater than the force experienced when the first vibration plate is deformed into a height difference, the excess clamping force will pass through Pass the rim to the skin. The process of energy transmission is shown in Figure 2.

technical problem

Due to the integrated structure of the electroacoustic transducer and the acoustic coupler, the transmission efficiency is low, the power consumption is large, and the signal distortion is large. At present, when bone conduction speakers are used in wireless earphone applications, a 1-2W power amplifier is needed to drive the speakers to achieve a user-acceptable volume level. The battery capacity of the wireless headset needs to be increased to maintain sufficient effective working time, which increases the cost and weight of the product. The signal distortion is large, which obviously reduces the user experience and reduces the quality of the product.

Technical solutions

In view of this, the present invention provides a bone conduction speaker for ultrasonic and electroacoustic systems. Aiming at the shortcomings of the prior art, in the electroacoustic transducer and acoustic wave transmission structure, a brand-new acoustic wave transmission design is adopted, and the acoustic wave coupling unit is independent. Complete energy transmission and frequency response control.

The purpose of the present invention is achieved through the following technical solutions:

A bone conduction speaker for ultrasonic and electro-acoustic systems, comprising a sound wave transducer and a sound wave coupler. The sound wave transducer is used to convert electric signals into sound wave vibration energy. The sound wave coupler is connected by a kinetic energy output connecting rod ( 106), positioning and elastic support sheet (107), kinetic energy balance pad (108), coupler damping shrapnel (109), coupler resonant shrapnel (110), sound wave load plate; the kinetic energy output connecting rod (106) is connected to The output end of the acoustic wave transducer transmits the acoustic vibration energy to the coupler resonant shrapnel (110); the positioning and elastic support plate (107), the kinetic energy balance pad (108), the coupler damping shrapnel (109) and A through hole is provided in the middle of the coupler resonant shrapnel (110), and the through hole is used to allow the kinetic energy output connecting rod (106) to pass through;

The coupler resonant shrapnel (110) is fixedly connected with the sound wave load plate; the coupler damping shrapnel (109) is connected with the shell of the bone conduction speaker; the kinetic energy balance gasket (108) is positioned and the elastic support plate (107) and the coupler damping Between the elastic pieces (109), the positioning and elastic support piece (107) is connected with the shell of the bone conduction speaker.

Further, the fixed connection between the coupler resonant shrapnel (110) and the sonic load board includes welding, glue connection or 3D printing as a whole.

Further, there is at least one layer of the acoustic wave load board.

Further, the acoustic wave load board has two layers, and the material of each layer is different.

Further, the coupler damping shrapnel (109) and the coupler resonant shrapnel (110) are respectively composed of at least one comb-shaped shrapnel.

Further, the number of the comb-shaped elastic pieces is between 1 and 100.

Further, the geometric shape of the coupler resonant shrapnel (110) includes but is not limited to the following shapes: square, circle, triangle, single array, single shrapnel, single dish or polygonal array.

Further, the material of the coupler resonant shrapnel (110) is a conductor material of acoustic waves.

Further, the material thickness of the coupler resonant shrapnel (110) is between 0.01-5 mm.

Further, the length of the non-cylindrical coupler resonant shrapnel (110) is between 1mm and 1000mm, and the width is between 0.1mm and 100mm; the diameter of the cylindrical coupler resonant shrapnel (110) is between 0.01 and 10mm , The length is between 0.1-1000mm.

Beneficial effect

The beneficial effects of the present invention are:

In the present invention, the transducer and the acoustic wave coupler are designed separately, and the transducer is focused on improving energy efficiency and reducing acoustic wave distortion. Acoustic wave couplers focus on transmission efficiency and frequency response control. The solid-state transmission acoustic wave coupler of the present invention will greatly improve the transmission efficiency of the coupling between the bone conduction earphone and the acoustic wave solid object and the solid object, which can greatly improve the conversion efficiency and minimize the waveform distortion. In terms of frequency response, bass has been greatly improved.

Description of the drawings

Fig. 1 is a schematic diagram of the structure of a bone conduction speaker in the prior art;

Figure 2 is a schematic diagram of the energy transmission process of a bone conduction speaker in the prior art;

Figure 3 is a schematic diagram of the structure of the acoustic wave transducer of the present invention;

4 is a schematic diagram of the cross-sectional structure of the bone conduction speaker of the present invention;

Figure 5 is a schematic diagram of the energy transmission process of the bone conduction speaker of the present invention;

Figure 6 shows the audio frequency spectrum with a fundamental frequency of 500 Hz;

Figures 7-1 to 7-7 are schematic diagrams of the resonant shrapnel of the coupler of various shapes according to the present invention;

Figure 8-1 is a graph showing the output power of a bone conduction speaker in the prior art;

Figure 8-2 is a graph of the output power of the bone conduction speaker of the present invention.

The reference signs are explained as follows:

101: shell and external magnetic circuit body, 102: magnet, 103: coil, 104: coil bracket, 105: elastic wave, 106: kinetic energy output connecting rod, 107: positioning and elastic support sheet, 108: kinetic energy balance pad , 109: Coupler damping shrapnel, 110: Coupler resonant shrapnel, 111: Acoustic wave load plate A layer, 112: Acoustic wave load plate B layer.

The best mode of the present invention

The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

The following describes the implementation of the present disclosure through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that, in the case of no conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present disclosure.

实施例一Example one

In order to better understand the present invention, the technical terms appearing in the present invention are explained as follows:

Sound waves: The present invention refers to all sound waves that cover ultrasound, infrasound, and human ears.

Acoustic wave transducer: The present invention refers to an electro-acoustic transducer device for ultrasound, infrasound, and all sound waves visible to the human ear.

Solid-state transmission acoustic wave coupler: The solid-state refers to the small change in the volume and shape of the solid when subjected to a small external force. The present invention refers to a form containing flexible and rigid substances. The full name refers to a device that couples acoustic vibration signals from one solid substance to another solid substance.

The present invention adopts a brand-new sound wave transmission design, and the sound wave transducer adopts the kinetic energy unit of a traditional moving coil speaker, as shown in the dashed box in FIG. 3. Except for the paper cone used to push the air, it retains all the functions of the traditional dynamic speaker, but in the device design, the transducer is designed to generate kinetic energy with the lowest energy loss to improve efficiency, and the signal distortion is serious. Technical innovation design for signal distortion. Such a design scheme is based on the relatively mature dynamic speaker transducer unit, low cost, and easy quality control.

A bone conduction speaker for ultrasonic and electroacoustic systems, including a sound wave transducer and a sound wave coupler, as shown in Figure 4.

The acoustic wave transducer of the present invention is composed of a shell and an outer magnetic circuit body 101, a coil 107, a magnet 102, and an elastic wave 105, and the main function is to convert electrical signals into acoustic vibration energy. The acoustic wave transducer can be a moving coil type, a moving iron type, or a piezoelectric ceramic or PVDF membrane electroacoustic transducer device. Its working principle is the same as that of a general speaker. It is a public technology and is not described as a technical focus.

The acoustic wave coupler of the present invention is composed of a kinetic energy output connecting rod 106, a positioning and elastic support piece 107, a kinetic energy balance pad 108, a coupler damping elastic piece 109, a coupler resonant elastic piece 110, and a sound wave load plate.

The sound wave output by the acoustic wave transducer is transmitted by the kinetic energy output connecting rod 106 to the coupler resonant shrapnel 110. The coupler resonant shrapnel 110 is composed of at least one comb-shaped shrapnel. Each shrapnel can be of different geometric shapes or different geometric sizes to determine itself The resonant frequency of the sonic wave is connected to the sonic load board to synthesize the required sonic frequency response characteristics on the load board.

The combination of the positioning and elastic support sheet and the elastic wave 105 is used to limit the axial movement of the coil without deviating to the surrounding.

The connection between the 110 and the sonic load board can be welding, glue, or 3D printing into a whole. The acoustic wave load board A layer 111, the acoustic wave load board B layer 112, and the coupler resonant shrapnel 110 determine the output frequency response curve. 111 and 112 are composed of different materials, and the purpose is to generate the required frequency response curve. The sonic load board can also be a single-layer material or a multi-layer material. The sound wave load board is responsible for receiving and synthesizing sound waves and transmitting the sound waves to the sound wave receptors.

The coupler damping elastic piece 109 is connected to the shell and outer magnetic circuit body 101, and the shell and outer magnetic circuit body 101 is also the shell of the bone conduction speaker of the present invention. It is used to alleviate the stress effect of external pressure on the electro-acoustic transducer, and at the same time improve the response speed in terms of improving the transient response.

The coupler damping shrapnel 109 is composed of comb-shaped shrapnel. Each shrapnel is a sound wave transmitter with a specific natural frequency. N shrapnels form the coupler damping shrapnel 109 with N frequency points, which are used to produce different sound waves at different frequencies. Damping effect. From this, we can understand that in the acoustic frequency domain, different materials, materials, and specific geometric dimensions can form damping shrapnel 109 with different frequency bandwidths. Figure 6 shows the audio frequency spectrum with a fundamental frequency of 500 Hz.

The coupler resonant shrapnel 110 is composed of comb-shaped shrapnel. Each shrapnel is a sound wave transmitter with a specific natural frequency. N shrapnels form a coupler resonant shrapnel 110 group at N frequency points to increase the bandwidth of the coupler. Therefore, we can understand that in the acoustic frequency domain, different materials, materials, and specific geometric dimensions can form the coupler resonant shrapnel 110 with different frequency bandwidths. The value of N is between 1-100.

The transmission frequency of the coupler resonant shrapnel 110 is determined by its material and geometric dimensions.

Based on the above principle, the appearance of the coupler resonant elastic piece 110 of the present invention can be any geometric shape. As long as the principle is consistent with the present invention, we can understand the same principle. The geometric shape can be square, circle, triangle, single array, single shrapnel, polygonal array. It can also be a single disk-shaped elastomer. As shown in FIGS. 7-1 to 7-6, any shape that is changed according to the principle of acoustics can be regarded as the same as the present invention. The composition of the coupler resonant shrapnel 110 can be any shape, which does not affect the acoustic engineer's understanding of the principle of this project. For example, replace the shrapnel with cylindrical material. We can understand the same principle.

The material of the coupler resonant shrapnel 110 can be any sound wave conductor, and can be any geometrically shaped material body, the thickness of the material is between 0.01-5 mm, and the length of the shrapnel is between 1 mm and 1000 mm. The width can be between 0.1mm-100mm. The cylindrical shrapnel can be 0.01-10mm in diameter and 0.1-1000mm in length.

It can also be a polygonal section of a three-solution interface body and any freely transformable section body, which can be understood as the same.

As shown in Figs. 7-7, the circular coupler resonant shrapnel is taken as an example for illustration. When the radius R is between R=1 and 1000 mm, the length L of the coupler resonant shrapnel 110; the width W can be any value of R. After the acoustic engineer understands the principle of this project, we can understand any changes in the shape and size of the coupler resonant shrapnel 110 within the R value range, and we can understand it as the same.

The number of the coupler resonant shrapnel 110 can be between 1 and 100. After the acoustic engineer understands the principle of this project, change the number of the coupler resonant shrapnel 110 between 1 and 100 and any shape and size within the R value range. We can understand the change in quantity as the same.

In the range of the R value of the coupler resonant shrapnel 110, the bending angles a1 and a2 can be between 1 and 360 degrees.

The value of the height H1 of the coupler resonant shrapnel 110 from the housing can be between 0.1 and 1000 mm.

As shown in the front view, the width W1 and height H of the damping shrapnel 109 can be any value of R value. After the acoustic engineer understands the principle of this project, he can change any shape and size change within the range of R value, and Any change in the contact position of the shell can be understood as the same.

The cross section of the coupler resonant shrapnel 110 and the damper shrapnel 109 can be strip-shaped, or cylindrical, triangular, or polygonal. After the acoustic engineer understands the principle of this project, change the coupler resonant shrapnel arbitrarily 110. The material of the damper shrapnel 109 and the cross-sectional shape of the shrapnel can be understood as the same.

The coupler resonant shrapnel 110 and the damper shrapnel 109 can be any sound-conducting material. When the acoustic engineer understands the principle of this project, we can understand the material change as the same.

The 111 and 112 connected to the resonant shrapnel group 110 of the combiner are sound wave load plates, which bear the function of receiving and transmitting sound waves. They can be a single layer of the same material, two layers or a multi-layer composite board. It can be square, circle, triangle, polygonal array, etc. The load plate is also part of the acoustic wave coupler. Different materials make up different frequency combinations. It can be a single material or a composite surface made of multiple materials. It can also be a special composite shape of 3D printing. The shape can be understood as a flat body of any shape or a shape made of a special shape, such as a spherical concave-convex surface, as long as it does not violate the principle of this project, we can understand it as the same.

The length and width direction of the polygonal coupler resonant shrapnel 110 may be 0.1-1000 mm, and the thickness may be 0.1-10 mm. It may also be an equilateral polygon or an irregular polygon. The diameter of the circle can be 1-1000mm.

Embodiments of the present invention

实施例一Example one

The combination of the positioning and elastic support sheet and the elastic wave 105 is used to limit the axial movement of the coil without deviating to the surroundings.

The 111 and 112 connected to the resonant shrapnel group 110 of the combiner are sound wave load plates, which bear the function of receiving and transmitting sound waves. They can be a single layer of the same material, two layers or a multi-layer composite board. It can be square, circle, triangle, polygonal array, etc. The load plate is also part of the acoustic wave coupler. Different materials make up different frequency combinations. It can be a single material or a composite surface made of multiple materials. It can also be a special composite shape of 3D printing. The shape can be understood as a flat body of any shape or a shape made of a special shape, such as a spherical concave and convex surface. As long as it does not violate the principle of this project, we can understand it as the same.

Industrial applicability

The electroacoustic transducer and the acoustic wave coupler of the present invention complete their work independently. There is better compatibility in energy conversion efficiency, sound quality and transmission efficiency.

Since the invention adopts the electroacoustic energy conversion system of the traditional loudspeaker and the earphone horn, the advantages are that the production cost is reduced and the production process is mature.

Due to the improvement of transmission efficiency, compared with the application of bone conduction earphone products, the current popular products on the market, the driving power of bone conduction speakers is 1-2W, after replacing the product of the present invention, only 0.3W driving power is required.

In terms of frequency response, the bass has been greatly improved. See Figure 8-1 and Figure 8-2. Under the same driving power, when the output power is 250Hz, the output sound pressure level of the existing product is increased from 62dBSPL to 92dBSPL.

In terms of audio distortion, it has increased by 1--10%.

Sequence Listing Free Content

The above is only to illustrate the embodiments of the present invention and not to limit the present invention. For those skilled in the art, all modifications, equivalent substitutions, and improvements made without creative work are within the spirit and principle of the present invention. Etc., should be included in the protection scope of the present invention.

Claims

A bone conduction speaker for ultrasonic and electro-acoustic systems, comprising a sound wave transducer and a sound wave coupler. The sound wave transducer is used to convert an electric signal into sound wave vibration energy. It is characterized in that: the sound wave coupler is composed of kinetic energy. The output connecting rod (106), the positioning and elastic support piece (107), the kinetic energy balance pad (108), the coupler damping shrapnel (109), the coupler resonant shrapnel (110), and the sound wave load plate are composed; the kinetic energy output connecting rod ( 106) Connect to the output end of the acoustic wave transducer, and transmit the acoustic vibration energy to the coupler resonant shrapnel (110); the positioning and elastic support piece (107), the kinetic energy balance gasket (108), and the coupler damping shrapnel A through hole is provided between (109) and the coupler resonant shrapnel (110), and the through hole is used to allow the kinetic energy output connecting rod (106) to pass through;

The coupler resonant shrapnel (110) is fixedly connected with the sound wave load plate; the coupler damping shrapnel (109) is connected with the shell of the bone conduction speaker; the kinetic energy balance gasket (108) is positioned and the elastic support plate (107) and the coupler damping Between the elastic pieces (109), the positioning and elastic support piece (107) is connected with the shell of the bone conduction speaker.
The bone conduction speaker for ultrasonic and electro-acoustic systems according to claim 1, characterized in that: the fixed connection of the coupler resonant shrapnel (110) and the sound wave load board includes welding, glue connection or 3D printing. One.
The bone conduction speaker for ultrasonic and electro-acoustic systems according to claim 1, characterized in that: the acoustic wave load board is at least one layer.
The bone conduction loudspeaker for ultrasonic and electroacoustic systems according to claim 3, wherein the acoustic wave load board has two layers, and the material of each layer is different.
The bone conduction speaker for ultrasonic and electroacoustic systems according to claim 1, characterized in that: the coupler damping shrapnel (109) and the coupler resonant shrapnel (110) are respectively composed of at least one comb-shaped shrapnel .
The bone conduction speaker for ultrasonic and electro-acoustic systems according to claim 5, wherein the number of the comb-shaped shrapnel is between 1 and 100.
The bone conduction speaker for ultrasonic and electroacoustic systems according to claim 5, characterized in that: the geometric shape of the coupler resonant shrapnel (110) includes but is not limited to the following shapes: square, circle, triangle, Single array, single shrapnel, single dish or polygonal array.
The bone conduction speaker for ultrasonic and electroacoustic systems according to claim 7, characterized in that: the material of the coupler resonant shrapnel (110) is a conductor material of sound waves.
The bone conduction speaker for ultrasonic and electroacoustic systems according to claim 8, characterized in that the material thickness of the coupler resonant shrapnel (110) is between 0.01-5 mm.
The bone conduction speaker for ultrasonic and electroacoustic systems according to claim 9, characterized in that: the length of the non-cylindrical coupler resonant shrapnel (110) is between 1mm and 1000mm, and the width is between 0.1mm and 100mm. The diameter of the cylindrical coupler resonant shrapnel (110) is between 0.01-10mm and the length is between 0.1-1000mm.