TWI399740B - Acoustic device - Google Patents

Description

Sound device

The invention relates to a sounding device, in particular to a sounding device based on the thermoacoustic principle.

As early as the beginning of the twentieth century, HDArnold et al. proposed a thermoacoustic sound generator based on the thermoacoustic effect, see the paper "The thermophone as a precision source of sound", HDArnold, IBCrandall, Phys. Rev. 22-38 (1917) and "On Some Thermal Effects of Electric Currents", William Henry Preece, Proceedings of the Royal Society of London, Vol. 30, pp 408-411 (1879-1881). The thermal sound generator realizes sound generation by introducing an alternating current into a conductor. The conductor must have a small heat capacity, a relatively thin thickness, and can rapidly transfer heat generated inside it to the surrounding gaseous medium. When the alternating current passes through the conductor, the conductor can rapidly rise and fall with the change of the alternating current intensity, and rapidly exchange heat with the surrounding gas medium, and the surrounding gas medium molecules move, and the density of the gas medium also changes, thereby generating sound waves. In the prior art, the most effective conductor was a metal.

HDArnold and IBCrandall describe a simple thermoacoustic burner in the document "The thermophone as a prec ision source of sound", Phys. Rev. 10, pp 22-38 (1917), which uses a platinum sheet as the sounding element. The thickness of the platinum sheet was 0.7 microns. Referring to FIG. 1, the sound emitting element 102 is fixed by a clamp 104. The sounding element 102 and the jig 104 are disposed on a surface of the substrate 108. A current lead 106 is electrically coupled to the sound emitting element 102 for inputting an electrical signal to the sound emitting element 102. Since the sounding frequency of the sounding element 102 is closely related to its heat capacity per unit area. The heat capacity per unit area is large, the sound frequency range is narrow, and the intensity is low; the heat capacity per unit area is small, and the sound frequency range is wide and the intensity is high. In order to obtain sound waves having a wider sounding frequency range and higher intensity, it is required that the heat capacity per unit area of the sounding element 102 is as small as possible. The metal platinum sheet with a smaller heat capacity is limited by the material itself to a thickness of at least 0.7 μm, and the 0.7 μm thick platinum sheet has a heat capacity per unit area of 2 × 10 ^-4 Joules per square centimeter Kelvin. Due to the limitation of the heat capacity per unit area of the material, the sounding frequency of the sounding device using the platinum sheet as the sounding element 102 can be up to 4 kHz and the sound intensity is low. Therefore, the above-mentioned thermal sound generator using the thermoacoustic effect cannot satisfy the daily application.

In view of this, it is necessary to provide a sounding device having a wide range of sounding frequencies, a high sounding intensity, and a good sounding effect.

A sounding device comprising: a sounding module comprising at least one first electrode, at least one second electrode and a thermal sounding film, the first electrode and the second electrode being spaced apart from each other with the thermoacoustic film An electrical connection, wherein the thermoacoustic film comprises a carbon nanotube structure, the sounding device further comprising a first protection structure, a second protection structure and an infrared reflection film, wherein the thermal acoustic film is disposed in the first Between a protective structure and a second protective structure, the infrared reflective film is disposed on a surface of the first protective structure.

A sounding device comprising: at least one first electrode, at least one second electrode, and a thermal sounding film, the first electrode and the second electrode being electrically connected to the thermosonic film at intervals, wherein the thermoacoustic film Including a carbon nanotube structure, the sounding device further includes an infrared reflective film and an infrared transmissive film disposed between the infrared reflective film and the infrared transmissive film.

Compared with the prior art, the sounding device provided by the present invention adopts a carbon nanotube structure as a thermal sounding film, and the carbon nanotube structure has a small heat capacity per unit area, and the sounding device has a wide range of sounding frequencies and sounds. High intensity and good sounding effect.

10,20,30‧‧‧ sounding device

102‧‧‧ Sounding components

104‧‧‧Clamp

106‧‧‧current lead

108‧‧‧ base

110,210,310‧‧‧Sound Module

112,212,312‧‧‧Hot sound film

114,214,314‧‧‧first electrode

116,216,316‧‧‧second electrode

120,220‧‧‧First protection structure

130,230‧‧‧Second protective structure

140,240,340‧‧‧Infrared reflective film

250,350‧‧‧Infrared transmissive film

318‧‧‧Support structure

1 is a schematic view showing the structure of a sounding device using a carbon nanotube film as a thermal sounding film in the prior art.

FIG. 2 is a schematic exploded perspective view of a sound emitting device according to a first embodiment of the present invention.

Fig. 3 is a scanning electron micrograph of a carbon nanotube film used as a thermoacoustic film in the first embodiment of the present invention.

4 is a schematic structural view of a sound emitting module using a plurality of electrodes according to a first embodiment of the present invention.

FIG. 5 is a schematic exploded perspective view of a sound emitting device according to a second embodiment of the present invention.

FIG. 6 is a schematic exploded perspective view of a sound emitting device according to a third embodiment of the present invention.

Hereinafter, a sound emitting device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 2, a first embodiment of the present invention provides a sound emitting device 10, which includes a sound emitting module 110, a first protection structure 120, a second protection structure 130, and an infrared reflection film 140. The first protection structure 120 and the second protection structure 130 are respectively disposed on two sides of the sound emitting module 110. The infrared reflective film 140 is disposed on a surface of the first protective structure 120.

The sound emitting module 110 includes a thermal sounding film 112, at least one first electrode 114, and at least one second electrode 116. The first electrode 114 and the second electrode 116 are electrically connected to the thermal sounding film 112 at intervals from each other. Specifically, the first electrode 114 and the second electrode 116 are spaced apart, and the thermal acoustic film 112 may be disposed between the first electrode 114 and the second electrode 116. The thermoacoustic film 112 can receive sound waves from the signals input by the first electrode 114 and the second electrode 116.

The thermal sounding film 112 is disposed between the first protection structure 120 and the second protection structure 130. The thermal sounding film 112 may include a carbon nanotube structure. The carbon nanotube structure includes a plurality of carbon nanotubes. The carbon nanotube structure is a self-supporting structure. The so-called self-supporting structure, that is, the plurality of carbon nanotubes in the carbon nanotube structure, is attracted to each other by the van der Waals force, so that the carbon nanotube structure has a specific shape, can be suspended, and still maintains its specific shape. In this embodiment, the thermal sounding film 112 is at least partially suspended between the first protection structure 120 and the second protection structure 130. Specifically, the thermal ac acoustic film 112 may be partially suspended between the first protection structure 120 and the second protection structure 130 by the first electrode 114 and the second electrode 116. The carbon nanotube structure is layered and has a large specific surface area. The carbon nanotube structure has a thickness of 0.5 nm to 1 mm. Preferably, the carbon nanotube structure has a thickness of 50 nm. The carbon nanotube structure may have a heat capacity per unit area of less than 2 x 10 ^-4 joules per square centimeter Kelvin. Preferably, the carbon nanotube structure has a heat capacity per unit area of greater than or equal to 1.7 x 10 ^-6 joules per square centimeter Kelvin and less than or equal to 1.7 x 10 ^-5 joules per square centimeter Kelvin. In this embodiment, the carbon nanotube structure has a heat capacity per unit area of 1.7×10 ^-6 joules per square centimeter Kelvin. The carbon nanotubes in the carbon nanotube structure include one or more of a single-walled carbon nanotube, a double-walled carbon nanotube, and a multi-walled carbon nanotube. The single-walled carbon nanotube has a diameter of 0.5 nm to 50 nm, the double-walled carbon nanotube has a diameter of 1.0 nm to 50 nm, and the multi-walled carbon nanotube has a diameter of 1.5. Nano ~ 50 nm.

The carbon nanotube structure may include at least one carbon nanotube film. Specifically, the carbon nanotube structure may include a plurality of carbon nanotube films laid in parallel and without gaps or/and laminated. The carbon nanotube membrane comprises a plurality of uniformly distributed carbon nanotubes, and the carbon nanotubes are tightly bonded by van der Waals force. The carbon nanotubes in the carbon nanotube film may be ordered or disorderly arranged. The so-called ordered arrangement means that the arrangement direction of the carbon nanotubes is regular. The so-called disordered arrangement means that the arrangement direction of the carbon nanotubes is irregular. Specifically, when the carbon nanotube structure includes a disordered arrangement of carbon nanotubes, the carbon nanotubes are intertwined or the carbon nanotube structure is isotropic; when the carbon nanotube structure includes an ordered arrangement of nai In the case of a carbon nanotube, the carbon nanotubes are arranged in a preferred orientation in one direction, or the carbon nanotube structure comprises a plurality of sections, and the carbon nanotubes are arranged in a preferred orientation in one direction in each section, in the adjacent two sections The carbon nanotubes can be arranged in different directions. Specifically, the carbon nanotube film comprises one or more of a carbon nanotube film, a carbon nanotube film, and a carbon nanotube film.

The carbon nanotube film comprises a plurality of carbon nanotubes arranged substantially parallel to each other and substantially parallel to the surface of the carbon nanotube film. Specifically, the carbon nanotube film comprises a plurality of carbon nanotubes connected end to end by van der Waals force and arranged in a preferred orientation along substantially the same direction. The carbon nanotube film can be obtained by directly pulling from the carbon nanotube array, and is a self-supporting structure. The carbon nanotube film may have a thickness of 0.5 nm to 100 μm, and the width is related to the size of the carbon nanotube array for pulling the carbon nanotube film, and the length is not limited. See Figure 3 for a scanning electron micrograph of the carbon nanotube film. Specifically, each carbon nanotube film comprises a plurality of continuous and aligned carbon nanotube segments. The plurality of carbon nanotube segments are connected end to end by Van der Waals force. Each of the carbon nanotube segments includes a plurality of carbon nanotubes that are parallel to each other, and the plurality of mutually parallel carbon nanotubes are tightly coupled by a van der Waals force. It can be understood that the carbon nanotube structures of different areas and thicknesses can be prepared by laying a plurality of carbon nanotube films in parallel and without gaps laying and/or laminating. When the carbon nanotube structure comprises a plurality of stacked carbon nanotube film, the arrangement direction of the carbon nanotubes in the adjacent carbon nanotube film forms an angle α, and α is greater than or equal to 0 degrees. And less than or equal to 90 degrees (0 ° ≦ α ≦ 90 °). The carbon nanotube film which is laminated in a plurality of layers, in particular, the carbon nanotube film which is disposed in a plurality of layers, has a higher strength than the single layer carbon nanotube film, thereby facilitating the improvement of the strength of the heat generating film 112. . For the structure of the carbon nanotube film and the preparation method thereof, please refer to the application filed by the Chinese Patent Publication No. 200833862, published on Feb. 12, 2008 by Fan Shoushan et al.

The carbon nanotube rolled film includes a uniformly distributed carbon nanotube. The carbon nanotube rolled film may be isotropic or comprise a plurality of parts, and the carbon nanotubes are arranged in a preferred orientation in one direction in each part, and the carbon nanotubes in the adjacent two parts may be different Oriented or aligned in the same direction. The carbon nanotubes in the carbon nanotube rolled film overlap each other. The carbon nanotube rolled film can be obtained by rolling an array of carbon nanotubes. The carbon nanotube array is formed on a surface of the substrate, and the carbon nanotubes in the prepared carbon nanotube rolled film form an angle β with the surface of the substrate of the carbon nanotube array, wherein β is greater than or equal to 0 degrees. And less than or equal to 15 degrees (0 ≦ β ≦ 15 °). The carbon nanotube crushing The membrane is a self-supporting structure that can be self-supporting without the need for substrate support. The carbon nanotube rolling film and the preparation method thereof are specifically referred to the patent application "Nano Carbon Tube" of the Republic of China Patent No. 200900348, which was filed on January 29, 2009 by Fan Shoushan et al. Method for preparing a film". The carbon nanotube flocculation membrane comprises carbon nanotubes which are intertwined and uniformly distributed, and the carbon nanotubes may have a length of more than 10 cm. The carbon nanotubes are attracted and entangled by van der Waals forces to form a network structure. The carbon nanotube flocculation membrane is isotropic. The carbon nanotubes in the carbon nanotube flocculation membrane are uniformly distributed and randomly arranged to form a large number of microporous structures, and the pore diameter is from 1 nm to 10 μm. For the specific description of the carbon nanotube film and the preparation method thereof, please refer to the patent application "Nano Carbon Tube" of the Chinese Patent Application No. 200844041, which was filed on May 16, 2007 by Fan Shoushan et al. Method for preparing a film".

The first electrode 114 and the second electrode 116 are formed of a conductive material and may have a shape of a rod or a strip. Specifically, the material of the first electrode 114 and the second electrode 116 may be selected from a metal, a metallic carbon nanotube, or the like. Wherein, the metal comprises stainless steel, tungsten, copper, molybdenum or silver. In the embodiment of the present invention, the first electrode 114 and the second electrode 116 are strip-shaped metal electrodes, and the strip-shaped metal electrodes may have a self-supporting structure. The first electrode 114 and the second electrode 116 can be used to support the thermal acoustic film 112 and input signals to the thermal acoustic film 112. The input signal includes an AC signal or an audio signal. Since the first electrode 114 and the second electrode 116 are spaced apart, the thermoacoustic film 112 can be applied to the sounding device 10 to access a certain resistance value to avoid short circuit phenomenon.

It can be understood that the sounding device 10 can further include a plurality of first electrodes 114 and a plurality of second electrodes 116. Referring to FIG. 4, the plurality of first electrodes 114 and the plurality of second electrodes 116 are alternately spaced apart, that is, there is a second electrode 116 between any two adjacent first electrodes 114, and any two adjacent There is a first electrode 114 between the second electrodes 116. Preferably, the distance between the plurality of first electrodes 114 and the plurality of second electrodes 116 is equal. Further, the plurality of first electrodes 114 may be electrically connected, and the plurality of second electrodes 116 may be electrically connected. Specifically, the plurality of first electrics The pole 114 can be electrically connected through a wire as a signal input terminal, and the plurality of second electrodes 116 can be electrically connected through a wire as another signal input terminal. In use, an electrical signal can be input to the thermal acoustic film 112 through the two signal input terminals. The above connection method can realize the parallel connection of the thermal acoustic film 112 between adjacent electrodes. The electric resistance of the thermal acoustic film 112 after the parallel connection is smaller than the electric resistance of the thermal acoustic film 112 before the parallel connection, and the operating voltage can be lowered.

In this embodiment, the carbon nanotube structure as the thermal sounding film 112 comprises a layer of carbon nanotube film. The carbon nanotubes are arranged in a preferred orientation in the same direction in the carbon nanotube structure. The sounding device 10 includes a first electrode 114 and a second electrode 116. The carbon nanotubes are arranged in a preferred orientation along the direction of the first electrode 114 to the second electrode 116. The carbon nanotube structure has a thickness of 50 nm. Since the carbon nanotube has a very large specific surface area, the carbon nanotube structure itself has good adhesion under the action of the van der Waals force, so when the carbon nanotube structure is used as the thermal sounding film 112, The first electrode 114 and the second electrode 116 and the thermoacoustic film 112 can be directly adhered and fixed, and form a good electrical contact.

The first protection structure 120 and the second protection structure 130 can be used to protect the sounding module 110. The first protection structure 120 and the second protection structure 130 may be in a layer shape or a plate shape. They are respectively disposed on two sides of the sound emitting module 110, wherein the first protection structure 120 is disposed on a side of the sounding device 10 facing the user. The materials of the first protection structure 120 and the second protection structure 130 are not limited, and only need to satisfy the better heat resistance. Preferably, the first protection structure 120 and the second protection structure 130 have a high sound transmittance. The shapes of the first protection structure 120 and the second protection structure 130 are not limited, and may be a plane or a curved surface. The materials of the first protection structure 120 and the second protection structure 130 may be selected from a conductive material such as a metal or an insulating material such as plastic or plastic. The metal includes one or more of stainless steel, carbon steel, copper, nickel, titanium, zinc, and aluminum. The first protection structure 120 and the second protection structure 130 may be a porous structure, such as a grid, or a non-porous structure, such as a glass plate, a quartz plate, or the like. When the glass plate or When the quartz plate is used as the second protective structure 130, the glass plate or the quartz plate should have good infrared transmission properties. In addition, when the glass plate or the quartz plate is used as the second protection structure 130, the first electrode 114 and the second electrode 116 may be directly formed on the surface of the second protection structure 130, at this time, the thermal acoustic film 112 may be suspended between the first electrode 114 and the second electrode 116.

In the embodiment of the present invention, the first protection structure 120 and the second protection structure 130 are both a porous structure. Specifically, the first protection structure 120 and the second protection structure 130 are both a plastic grid, and the plastic grid has a plurality of through holes. The total area of the through holes of the first protection structure 120 and the second protection structure 130 respectively may be greater than 0% and less than 100% of the area of the first protection structure 120 and the second protection structure 130, respectively. The total area of the through holes in the first protection structure 120 and the second protection structure 130 is between 20% and 99% of the area of the first protection structure 120 and the second protection structure 130, respectively. The distribution and shape of the plurality of through holes are not limited.

The infrared reflective film 140 is spaced apart from the thermal sounding film 112. The infrared reflective film 140 may be disposed on an outer surface or an inner surface of the first protective structure 120. The infrared reflective film 140 has better infrared reflection performance and can change the direction of propagation of infrared rays radiated from the thermal sounding film 112. The infrared reflective film 140 can be used to reflect infrared rays (including near infrared rays and far infrared rays) radiated from the thermal sounding film 112 to the user side to the other side of the thermal sounding film 140 (ie, the side facing away from the user). Preferably, the infrared reflective film 140 also has a better heat insulating effect. The material of the infrared reflective film 140 is not limited, and only needs to satisfy a high infrared reflectance. The infrared reflectance of the infrared reflective film 140 may be 20% or more and 100% or less. Preferably, the infrared reflective film 140 has an infrared reflectance of 70% or more and 99% or less. In this embodiment, the infrared reflection film 140 has an infrared reflectance of 95%. The infrared reflective film 140 may include a substrate and a reflective film disposed on the surface of the substrate. The reflective film is a metal reflective film. The metal includes materials such as gold, silver or copper which have better infrared reflection properties. The substrate comprises a polymer or a fabric. The polymer includes a polyester film or the like. The metal reflective film can be sputtered on the surface of the substrate A metal material with a high infrared reflectance is prepared. In addition, at least one dielectric film may be further disposed on the surface of the metal reflective film away from the substrate, and the material of the dielectric film may include ruthenium oxide, magnesium fluoride, ruthenium dioxide or aluminum oxide. The dielectric film can be used to protect the metal reflective film. The infrared reflective film 140 may be composed of a transparent material or an opaque material. Preferably, the infrared reflective film 140 is composed of a transparent material. In this embodiment, the infrared reflective film 140 is provided with a silver film on the surface of the transparent polyester film, and the infrared reflective film 140 is disposed on the outer surface of the first protective structure 120. When the first protective structure 120 is a non-porous structure, the infrared reflective film 140 may include only one metal reflective film, and the metal reflective film may also be directly formed on the surface of the first protective structure 120.

The distance between the infrared reflective film 140 and the thermal sounding film 112 is not limited. Preferably, the infrared reflective film 140 preferably does not affect the heat exchange between the thermal acoustic film 112 and the surrounding medium, and can effectively reflect infrared rays to the rear side of the sounding device 10. In this embodiment, the distance between the infrared reflective film 140 and the thermal sounding film 112 is about 10 mm.

When the sound generating device 10 is in use, since the carbon nanotube structure is composed of a uniformly distributed carbon nanotube, and the carbon nanotube structure is layered and has a large specific surface area, the carbon nanotube structure has The smaller unit area heat capacity and larger heat dissipation surface, after inputting the signal, the carbon nanotube structure can rapidly rise and fall, generate periodic temperature changes, and quickly exchange heat with the surrounding medium to make the density of the surrounding medium. Changes occur periodically, which in turn makes a sound. The principle of sound emission of the thermal sounding film 112 is "electric-thermal-acoustic" conversion. When the sounding device 10 is in use, the thermal sounding film 112 thermally radiates to the surroundings in an electromagnetic wave and rapidly exchanges heat with the surrounding medium. The present invention controls the propagation direction of the infrared rays radiated from the thermal sounding film 112 by providing an infrared reflecting film 140 on the surface of the first protective structure 120 facing the user side of the sound emitting device 10, and the thermal sounding film 112 is directed to The infrared rays radiated from the user side are reflected to the other side of the thermal sounding film 112, so that the user on the side of the infrared reflecting film 140 does not feel the heat.

The sound pressure level of the sounding device 10 provided by the embodiment of the present invention is greater than 50 decibels per watt sound pressure level, and the sounding frequency ranges from 1 Hz to 100,000 Hz (ie, 1 Hz to 100 kHz). The sounding device may have a distortion of less than 3% in a frequency range of 500 Hz to 40,000 Hz. When a single-layer carbon nanotube film of A4 paper size is used as the thermal sounding film 112, a microphone is set at a position 5 cm away from the thermal sounding film, and the input sound voltage is 50 volts, and the sound generating device is measured. The sounding frequency of 10 is greater than or equal to 100 Hz and less than or equal to 100,000 Hz, and the vocal intensity is greater than 50 dB per watt sound pressure level. The sounding device 10 has a wide range of sounding frequencies, a large intensity, and a good sounding effect.

Referring to FIG. 5, a second embodiment of the present invention provides a sound emitting device 20, which includes a sound emitting module 210, a first protection structure 220, a second protection structure 230, an infrared reflection film 240, and an infrared Transmissive film 250. The sound emitting module 210 includes a thermal sounding film 212, at least one first electrode 214, and at least one second electrode 216. The first protection structure 220 and the second protection structure 230 are respectively disposed on two sides of the sound emitting module 210. The infrared reflective film 240 is disposed on a surface of the first protective structure 220. The infrared transmitting film 250 is disposed on the surface of the second protective structure 230.

The sounding device 20 provided by the second embodiment of the present invention has substantially the same structure as the sounding device 10 of the first embodiment. The difference is that the sound emitting device 20 provided by the second embodiment of the present invention further includes an infrared transmitting film 250 disposed on the surface of the second protective structure 230. The infrared transmitting film 250 is advantageous for increasing the infrared transmittance of the sound emitting device 20 on the side of the second protective structure 230. In addition, when the second protection structure 230 adopts a porous structure such as a grid, the infrared transmission film 250 can further function to protect the thermal acoustic film 212. The material of the infrared transmissive film 250 may be a material having a high infrared transmittance. The infrared transmission film 250 may have an infrared transmittance of 10% or more and 99% or less. Preferably, the infrared transmission film 250 may have an infrared transmittance of 60% or more and 99% or less. In the embodiment, the infrared transmission film 250 has an infrared transmittance of 90%. The material of the infrared transmission film 250 includes zinc sulfide, zinc selenide, diamond, diamond-like carbon, etc., which has high infrared absorption in the infrared band. Over-rate material.

Referring to FIG. 6 , a third embodiment of the present invention provides a sound emitting device 30 . The sound emitting device 30 includes a sound emitting module 310 , an infrared reflecting film 340 , and an infrared transmitting film 350 . The infrared reflecting film 340 and the infrared transmitting film 350 are respectively disposed on two sides of the sound emitting module 210 and are fixed to the sound emitting module 310. The sound emitting module 310 includes a thermal sounding film 312, a first electrode 314, a second electrode 316, and a supporting structure 318. The thermal ac acoustic film 312 is disposed between the infrared reflective film 340 and the infrared transmissive film 350.

The sounding device 30 provided in the third embodiment is basically the same in structure as the sounding device 10 of the first embodiment. The difference is that the sounding device 30 provided by the third embodiment of the present invention includes only one sound emitting module 310, an infrared reflecting film 340 and an infrared transmitting film 350, and the sounding module 310 further includes a supporting structure 318. The sounding device 30 does not include the first protection structure and the second protection structure. The infrared reflective film 340 and the infrared transmissive film 350 may further function to protect the thermal acoustic film 312. The support structure 318 is made of an insulating material, which may be glass, ceramic, resin, wood material, quartz or plastic. The support structure 318 can include four side panels (not labeled) connected end to end, that is, a first side panel, a second side panel, a third side panel, and a fourth side panel. The first side panel, the second side panel, the third side panel, and the fourth side panel may be integrally formed. The first side plates are opposite to and spaced apart from the third side plates, and the second side plates are disposed opposite to and parallel to the fourth side plates. The first side panel, the second side panel, the third side panel and the fourth side panel together form a space, and the thermal sounding film 312 is disposed in the space through the first electrode 314 and the second electrode 316. Both ends of the first electrode 314 and the second electrode 316 are supported by two side plates of the support structure 318 which are arranged in parallel with each other. The infrared reflective film 340 and the infrared transmissive film 350 preferably have a self-supporting structure. The size of the infrared reflective film 340 and the infrared transmissive film 350 may be the same as the size of the support structure 318. The infrared reflecting film 340 and the infrared transmitting film 350 may be fixedly disposed on the side plates of the supporting structure 318 by means of a bonding agent or the like. In this embodiment, the infrared reflective film 340 and infrared The transmissive film 350 is fixedly disposed on the four side plates of the support structure 318 by an adhesive. It can be understood that the infrared transmission film 350 in this embodiment is an optional structure.

The sounding device provided by the invention has the following advantages: First, the carbon nanotube structure is used as a thermal sounding film, the carbon nanotube structure has a small heat capacity per unit area, and the sounding frequency of the sounding device is wide. The vocal intensity is high and the vocalization effect is good. Secondly, the sounding device provided by the present invention further reflects infrared rays emitted from the side of the infrared ray-sounding film to the other side of the heat-sounding film by providing an infrared reflecting film on the side of the sound-emitting module, thereby further positioning The user on one side of the infrared reflective film does not feel the heat. Secondly, the sounding device may be composed of a layered protective structure and a thermal sounding film, and a thermal sounding film is disposed between the two layered protective structures, and the layered protective structure can protect the thermal sounding film to make the heat sounding The film is not easily damaged by external force. Thirdly, the sounding device may only include a sounding module, an infrared reflecting film and an infrared transmitting film, and the infrared reflecting film and the infrared transmitting film may further protect the hot sounding film, thereby enabling the The structure of the sounding device is relatively simple.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by those skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10‧‧‧ Sounding device

110‧‧‧ Sound Module

112‧‧‧Hot sound film

114‧‧‧First electrode

116‧‧‧Second electrode

120‧‧‧First protection structure

130‧‧‧Second protective structure

140‧‧‧Infrared reflective film

Claims (22)

A sounding device comprising: a sounding module comprising at least one first electrode, at least one second electrode and a thermal sounding film, the first electrode and the second electrode being spaced apart from each other with the thermoacoustic film The electrical connection is improved in that the thermal acoustic film comprises a carbon nanotube structure, and the sounding device further comprises a first protective structure, a second protective structure and an infrared reflective film, wherein the thermal acoustic film is disposed at The infrared reflective film is disposed on the surface of the first protective structure between the first protective structure and the second protective structure. The sounding device of claim 1, wherein the infrared reflective film is spaced apart from the thermal sounding film. The sounding device according to Item 1, wherein the infrared reflective film has an infrared reflectance of 20% or more and 100% or less. The sounding device of claim 1, wherein the infrared reflective film comprises a substrate and a reflective film disposed on the surface of the substrate. The sounding device of claim 4, wherein the substrate comprises a polymer film or fabric. The sounding device of claim 4, wherein the reflective film is a metal reflective film, and the metal is gold, silver or copper. The sounding device of claim 4, wherein the infrared reflective film further comprises at least one dielectric film disposed on a surface of the reflective film away from the substrate. The sounding device according to Item 7, wherein the material of the dielectric film is cerium oxide, magnesium fluoride, cerium oxide or aluminum oxide. The sounding device of claim 1, wherein the sounding device further comprises an infrared transmitting film disposed on a surface of the second protective structure. The sounding device of claim 9, wherein the material of the infrared transmission film is zinc sulfide , zinc selenide, diamond or diamond-like carbon. The sounding device according to claim 9, wherein the infrared transmission film has an infrared transmittance of 10% or more and 100% or less. The sounding device of claim 1, wherein the first protection structure and the second protection structure have a plurality of through holes. The sounding device of claim 12, wherein the total area of the plurality of through holes of the first protection structure and the second protection structure respectively accounts for 20% of the area of the first protection structure and the second protection structure. Between % and 99%. The sounding device of claim 1, wherein the carbon nanotube structure comprises at least one carbon nanotube film. The sounding device according to claim 14, wherein the carbon nanotube film comprises a plurality of carbon nanotubes connected end to end and arranged in a preferred orientation in the same direction, and the vanadium force is passed between the carbon nanotubes. Connected to each other. The sounding device of claim 15, wherein the carbon nanotube structure comprises a plurality of carbon nanotube film laminate arrangements. The sounding device according to claim 1, wherein the heat generating film has a heat capacity per unit area of less than 2 × 10 ^-4 joules per square centimeter Kelvin. The sounding device of claim 1, wherein the thermal sounding film is at least partially suspended between the first protective structure and the second protective structure. The sounding device of claim 18, wherein the thermoacoustic film is disposed between the first protective structure and the second protective structure by at least partially floating at least two electrodes. A sounding device comprising: at least one first electrode, at least one second electrode, and a thermal sounding film, the first electrode and the second electrode being electrically connected to the thermosonic film at intervals, the improvement being that the heat The sounding film includes a carbon nanotube structure, and the sounding device further includes an infrared reflecting film and an infrared transmitting film, and the heat generating film is disposed on the infrared reflecting film and the infrared Between the transmissive films. The sounding device of claim 20, further comprising a support structure, wherein the at least one first electrode and the at least one second electrode are supported by the support structure. The sound emitting device according to claim 21, wherein the infrared reflective film and the infrared transmitting film are fixedly disposed on the support structure and spaced apart from the thermal sounding film.