TWI686091B - Film speaker - Google Patents

Abstract

Present invention relates to film speaker comprising: a film substrate, the film substrate defined a working area; two conductive layer at least covering the upper surface and lower surface of the working area of the film substrate; two annular conductor disposed on two opposite sides of the film substrate and bonded to the edge of the two conductive layers located outside the working area; and two conductive members, the two conductive members, the shape of the two conductive members are corresponding to the two annular conductors and covering the two annular conductors; the two conductive members are connected to the electrodes of a source signal output.

Description

Film speakers

The invention relates to a thin film speaker, in particular to a thin film speaker used on an audio device or an electronic product to output sound signals.

With the advancement of the times and consumer demand for portability, consumer electronic products are gradually developing towards light, thin and miniaturized. Therefore, the various components used in electronic products are also toward the direction of miniaturization and thinning development of.

For electronic products such as mobile phones, portable wearable devices, digital assistants, etc., the speaker is responsible for the function of enabling the electronic product to convert the electronic signal into an audio signal, so it is one of the important components in the electronic product. General speakers can be divided into dynamic, electrostatic, and piezoelectric according to the operating principle. Among them, dynamic speakers are the most widely used types at present, but this type of dynamic coil The structure of the speaker needs to be composed of permanent magnets, coils and speakers, so it is bulky and not easy to be thin, so the application of light and thin mobile electronic devices or wearable electronic devices will cause the volume and thickness of the electronic device to increase. Facing the design trend of miniaturization and thinning of electronic products, moving coil speakers are subject to volume constraints and cannot be further developed.

The function principle of the traditional electrostatic loudspeaker is to hold two conductive electrode plates with open holes and hold a conductive diaphragm to form a capacitor. By supplying the diaphragm DC bias and AC voltage to the audio of the two fixed electrodes, according to Coulomb rule In order to make the conductive diaphragm move forward and backward under the synergy of electrostatic force, and vibrate with the audio signal source, but the electrostatic speaker needs to be driven by high voltage, so it needs to be connected to an amplifier with high unit price and huge volume, which makes it impossible to popularize.

Piezoelectric speakers use the piezoelectric effect of piezoelectric materials. When an electric field is added to the piezoelectric material, the deformation characteristics of the material are used to promote the vibration film to sound. The piezoelectric speaker has a simple structure and does not require an external speaker, so it can be fixed in a limited space, and is the first choice for the development of miniaturized electronic products. However, most of the existing piezoelectric speakers have a diaphragm and a piezoelectric element that are two different elements, and the area of the piezoelectric element relative to the diaphragm is relatively small, so it cannot form a large amplitude, which leads to the efficiency of sound generation Poor, and can only achieve excellent performance in the high-frequency range, poor performance for low-frequency and high distortion.

At the same time, although the existing piezoelectric speaker uses a thin film as a sounding element, it needs to be additionally provided with a conductive structure for connecting the driving circuit and the piezoelectric element, and a fixing frame for supporting the diaphragm, so the structure is still quite Complexity, which leads to the shortcomings of rising manufacturing costs.

Due to the above reasons, various inconveniences in the use of existing piezoelectric thin-film speakers have been caused. Therefore, how to solve the aforementioned problems through structural improvement has become one of the important issues that this business wants to solve.

The main object of the present invention is to provide a thin film speaker, which includes: a thin film substrate, wherein the thin film substrate has opposite upper and lower sides, and the upper and lower sides of the thin film substrate can respectively define a working area ; Two conductive layers, the two conductive layers are respectively disposed on the upper side and the lower side of the film substrate, and at least cover the film substrate is located in the working area of the upper side and the lower side; two ring conductors, The two ring-shaped conductors are respectively disposed on two opposite sides of the film substrate; the two ring-shaped conductors are opposed to each other and respectively surround the edge of the working area, and are respectively attached to the edges of the two conductive layers located at the periphery of the working area ; And two conductive elements, the two conductive elements are respectively disposed on a side of the two ring conductors relative to the film substrate, the two conductive elements are in the form of a ring corresponding to the two ring conductors, and cover contact with the The two ring conductors are opposite to one side of the film substrate; the two conductive elements are respectively connected to the two poles of a sound source signal output, so that the sound source signal output by the sound source signal can be conducted through the two conductive elements and the two ring conductors To the two conductive layers.

A preferred embodiment of the present invention, wherein the film substrate is a polyvinylidene fluoride (PVDF) film.

A preferred embodiment of the present invention, wherein the two conductive layers are metal films or metal oxide films.

A preferred embodiment of the present invention, wherein the two ring-shaped conductors are conductive adhesives or metal conductor layers disposed on the surfaces of the two conductive layers by electroplating.

A preferred embodiment of the present invention further includes a frame structure disposed at a position where the film substrate is located at the edge of the working area, so that the film substrate forms a planar state within the working area.

A preferred embodiment of the present invention, wherein the frame structure includes: a lower frame and an upper frame, the upper frame and the lower frame are oppositely disposed on the upper side and the lower side of the edge of the working area of the film substrate, And it is relatively sandwiched between the upper side and the lower side of the film substrate to fix the film substrate.

A preferred embodiment of the present invention, wherein the side of the lower frame facing the film substrate has a top surface, the top surface has a slot in the center, and the side of the upper frame facing the film substrate has a bottom surface, The bottom mask has an engaging flange corresponding to the clamping groove, and when the upper frame body and the lower frame body are relatively clamped, the engaging flange can be engaged in the clamping groove, and the film substrate is aligned The material at the position of the engaging flange and the engaging slot should be pressed into the engaging slot, and the film base material should be formed corresponding to the engaging flange and the material at the engaging slot to form the engaging flange And the concave and convex shape corresponding to the slot.

A preferred embodiment of the present invention, wherein the film substrate can be attached to the surface of a plate body, and the film substrate is formed into a planar state through the plate body.

A preferred embodiment of the present invention, wherein the film substrate is provided with at least one perforation within the working area.

A preferred embodiment of the present invention, wherein the shape of the working area is selected from one of a circle, a rectangle, a triangle, an ellipse, and a polygon, or a combination thereof.

The beneficial effect of the present invention is that it can simplify the structure of the thin-film speaker, and improve its sound generation efficiency, simplify the assembly procedure, and reduce the cost.

In order to further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings are provided for reference and explanation only, and are not intended to limit the present invention.

1‧‧‧film speaker

10‧‧‧ film substrate

101‧‧‧Surface

102‧‧‧Lower surface

11, 11a, 11b ‧‧‧ working area

12‧‧‧Perforation

20‧‧‧conductive layer

30‧‧‧ring conductor

40‧‧‧conductive element

41‧‧‧ Connection

42‧‧‧Contact Department

50‧‧‧Audio source signal output

60‧‧‧Frame structure

61‧‧‧Upper frame

611‧‧‧Snap flange

62‧‧‧Lower frame

621‧‧‧Card slot

70‧‧‧Board

FIG. 1 is a schematic cross-sectional view of a first embodiment of a thin film speaker of the present invention.

2 is a schematic diagram of a three-dimensional structure of a first embodiment of a thin film speaker of the present invention.

3 to 6 are schematic plan views of various embodiments of the film substrate used in the first embodiment of the film speaker of the present invention.

7 is a schematic diagram of a combined cross-sectional structure of a second embodiment of the thin film speaker of the present invention.

FIG. 8 is a schematic view of the top structure of the second embodiment of the thin film speaker of the present invention.

9 is a schematic diagram of a three-dimensional exploded structure of the second embodiment of the thin film speaker of the present invention.

10 is a schematic diagram of a cross-sectional structure of a third embodiment of the thin film speaker of the present invention.

11 is a schematic diagram of a three-dimensional structure of a film substrate used in a fourth embodiment of the film speaker of the present invention.

12 is a schematic diagram of a three-dimensional structure of another modified embodiment of the film substrate used in the fourth embodiment of the film speaker of the present invention.

[First embodiment]

As shown in FIGS. 1 and 2, the present invention provides a thin film speaker 1. The structure of the thin film speaker 1 of the present invention includes: a thin film substrate 10 made of a polymer material to a thin film or sheet , The upper and lower sides of the film substrate 10 have an upper side and a lower side opposite; and two conductive layers 20, the two conductive layers 20 are made of conductive material, and are respectively disposed on the upper side of the film substrate 10 With the lower side on.

The thickness of the film substrate 10 selected for the film speaker 1 of the present invention is preferably less than 0.3 mm. The area of the film substrate 10 used to emit sound is defined as a working area 11. The two conductive layers 20 cover at least the upper and lower sides of the film substrate 10 within the working area 11. The film substrate 10 is preferably made of polyvinylidene fluoride (PVDF) material, or a film or plate made of other polymer materials capable of generating piezoelectric effect.

The two conductive layers 20 are disposed on the upper and lower sides of the film substrate 10 in a patterned manner, and at least cover the upper surface 101 and the lower surface 102 of the film substrate 10 within the working area 11, and the film substrate The upper and lower surfaces 101 and 102 of the material 10 are closely attached. The two conductive layers 20 of the present invention can be selected from metal materials, such as: copper (Cu), silver (Ag), chromium (Cr), nickel (Ni), titanium (Ti) and other metal materials, or metals with conductivity Metal oxide films, such as titanium nitride (TiN) and indium tin oxide (ITO) films. The two conductive layers 20 can be provided on the surface of the film substrate 10 by vapor deposition, sputtering, electroplating, or coating.

The film substrate 10 is further provided with two ring conductors 30 on the upper and lower sides of the edge of the working area 11. The two ring conductors 30 are opposite to each other and surround the edge of the working area 11 respectively, and are electrically conductive with the two The layer 20 is connected at the edge of the periphery of the working area 11. In the present invention, the two ring-shaped conductors 30 can be selected as conductive glue, or can be made of metal conductors provided on the surface of the conductive layer 20 by electroplating or coating.

Two conductive elements 40 are further provided on the outer sides of the two ring-shaped conductors 30. The bodies of the two conductive elements 40 are ring-shaped bodies corresponding to the two ring-shaped conductors 30. The width of the ring-shaped portion of the body of the two conductive elements 40 is greater than or equal to two The width of the ring-shaped conductor 30 can therefore cover one side of the two ring-shaped conductors 30 that is in contact with the film substrate 10. And the two conductive elements 40 are respectively connected to the two output electrodes of a sound source signal output 50, so that the sound source signal of the sound source signal output 50 can be conducted to the two ring conductors 30 through the two conductive elements 40, and further through the two The ring-shaped conductor is conducted to the two conductive layers 20.

As shown in FIG. 2, in this embodiment, the two conductive elements 40 can be a flexible circuit board, or a conductor made of a polymer polymer plated with a conductor on the surface, for example, a pair of metal plates plated on the surface Ethylene phthalate (PET). And the two leads At least one side of the annular body of the electrical component 40 further extends a connecting portion 41, and a contact portion 42 is provided at the end of the connecting portion 41 for connecting with the output electrode of the audio signal output device.

In the present invention, since the film substrate 10 is made of a polymer material capable of generating piezoelectric effect, and the two conductive layers 20 cover the two surfaces of the working area 11 of the film substrate 10, therefore, when the voltage of the audio signal is transmitted After reaching the two conductive layers 20, the two conductive layers 20 can generate an electric field, which in turn causes the film substrate 10 to generate an inverse piezoelectric effect, thus causing the working area of the film substrate 10 to vibrate, thereby converting the sound source signal into sound output. And because the conductive layer 20 is tightly bonded to the surface of the film substrate 10, when the film substrate 10 vibrates, the two conductive layers 20 will also vibrate together with the film substrate 10.

As shown in FIGS. 3 to 6, it is a variety of implementations of the thin film speaker 1 according to the first embodiment of the present invention. With the thin-film speaker 1 made by the technology of the present invention, the working area 11 on the film substrate 10 can be planned into various geometric shapes, and the conductive layer 20 and the ring-shaped conductor 30 can also be changed according to the shape change of the working area 11. As shown in FIGS. 3 and 4, circular and rectangular working regions 11 are respectively planned on the film substrate 10, and the conductive layer 20 and the ring-shaped conductor 30 are also circular and rectangular according to the shape of the working region 11. Also in the embodiment shown in FIG. 5, two working regions 11a and 11b with different shapes are planned on the film substrate 10, and the conductive layer 20 and the ring are provided on the surface and periphery of the working region 11a and the working region 11b, respectively状 conductor30. As also shown in the embodiment shown in FIG. 6, the working area 11 provided on the surface of the film substrate 10 presents a composite shape area composed of a plurality of rectangles, and the conductive layer 20 and the ring conductor 30 are also designed to work with the working area 11 matching shapes.

Of course, the shape of the working area 11 provided on the film substrate 10 of the present invention is not limited to those disclosed in the above embodiments, and the shape of the working area 11 may be selected from one of a circle, a rectangle, a triangle, an ellipse, and a polygon , Or a composite shape composed of various geometric shapes.

From the embodiments disclosed in FIGS. 3 to 6, the thin film speaker 1 of the present invention can be understood It is possible to plan and set a working area 11 of any shape on the film substrate 10 through patterning technology, and the number of working areas 11 is not limited to one. Therefore, the present invention has many possibilities of different application modes, for example: in the same film The substrate 10 is provided with a plurality of working regions 11 that accept input from different sound sources, or a working region capable of producing different audio characteristics is planned on the film substrate 10 (for example, high-frequency audio and The low-frequency working area 11), thus making the thin film speaker 1 of the present invention more flexible in operation and making it easier to adjust for better sound quality.

[Second Embodiment]

As shown in FIGS. 7 to 9, the second embodiment of the present invention further includes a frame structure 60 for supporting the film substrate 10 so that the film substrate 10 at least within the working area 11 forms a planar state. In this embodiment, the frame structure 60 is disposed at the edge of the working area 11 of the film substrate 10. The frame structure 60 includes: a lower frame 62 and an upper frame 61, the upper frame 61 and the lower The frame body 62 is relatively disposed on the upper side and the lower side of the edge position of the working area 11 of the film substrate 10, and is relatively sandwiched on both sides of the film substrate 10. The upper frame 61 and the lower frame 62 are also clamped to the outer sides of the ring conductor 30 and the two conductive elements 40, respectively, for pressing the ring conductor 30 and the two conductive elements 40 into contact with the two conductive layers 20 outer side to improve the stability of signal transmission.

In this embodiment, the lower frame of the frame structure 60 has a top surface on the side facing the film substrate, and a ring-shaped slot 621 is formed in the center of the top surface, and the upper frame 61 faces the film substrate One side of 10 has a bottom surface, the bottom mask has an engaging flange 611 corresponding to the engaging groove 621 of the lower frame body, when the upper frame body 61 and the lower frame body 62 are relatively clamped, the engaging convex The edge 611 can be engaged in the engaging groove 621, and the film substrate 10 is pressed into the engaging groove 621 by pressing the material corresponding to the engaging flange 611 and the engaging groove 621.

As shown in FIGS. 7 and 9, since the groove 621 and the engaging flange 611 are perpendicular to the surface of the film substrate 10 respectively, when the material at the edge of the film substrate 10 is affected When the engaging flange 611 is driven to be engaged in the engaging groove 621, the film substrate 10 will be formed corresponding to the engaging flange 611 and the material at the position of the engaging groove 621 and the engaging flange 611 and The concave-convex shape corresponding to the slot 621, and the material driving the film substrate 10 at the edge of the working area 11 is subjected to vertical tension, so that the material of the film substrate 10 within the working area 11 produces horizontal strain, In addition, the material of the film substrate 10 generates tensile stress.

The second embodiment of the present invention can make the film substrate 10 form a planar structure through the above structure, so that the film substrate 10 can be easily installed and fixed on other electronic products. At the same time, the material of the film substrate 10 located at the edge of the working area 11 can be deformed through the engaging flange 611 and the locking groove 621, and at the same time, a tensile force is generated on the film substrate 10 within the working area 11 As a result, the film base material 10 in the working area 11 generates tensile stress to form a tight state.

In the second embodiment of the present invention, the shape of the engaging flange 611 and the engaging groove 621 of the frame structure 60 can be further changed to cause the film substrate 10 to generate different degrees of strain, so as to adjust or change the film substrate 10 to work. The material in the area of the area 11 bears the magnitude of the tensile stress to achieve the purpose of adjusting the sound quality.

[Third Embodiment]

As shown in FIG. 10, the third embodiment of the present invention is to further attach the film substrate 10 to a plate body 70, through which the film substrate 10 is formed into a flat state. In this embodiment, the thin-film speaker 1 of the present invention can be formed into a flat-plate-shaped structure through the plate body 70, and thus it can be easily mounted and fixed on other electronic products.

[Fourth Embodiment]

As shown in FIGS. 11 and 12, the film speaker 1 according to the fourth embodiment of the present invention is further provided with a through hole 12 in the working area 11 of the film substrate 10. In this embodiment, the size and shape of the perforations 12 can be changed according to actual needs. For example, as shown in FIG. 11, the perforations 12 are circular, while in the embodiment shown in FIG. 12, the perforations 12 are rectangular.

The purpose of the fourth embodiment is to provide perforations 12 on the film substrate 10, which can be used to change the audio or sound quality produced by the film speaker, or the perforations 12 can be designed to accommodate Space for other electronic components.

[Benefits of invention]

The beneficial effects of the film speaker of the present invention are as follows:

1. The main body of the thin film speaker 1 of the present invention is a sandwich structure composed of a thin film substrate 10 and two conductive layers 20, so its structure is simple, and the thin film substrate 10 located in the working area 11 are all vibrating diaphragms , Thus improving the efficiency of its sound output.

2. The thin-film speaker 1 of the present invention uses a ring conductor 30 and a ring-shaped conductive element 40 as the conductor structure for transmitting the audio signal to the two conductive layers 20, so that the voltage of the audio signal can be stably transmitted to the entire conductive layer 20 and assembled It is only necessary to bond the ring conductor 30 and the ring-shaped conductive element 40 on the surface of the conductive layer 20 by bonding or crimping. Therefore, the manufacturing and assembly process becomes quite simple.

The above are only the preferred and feasible embodiments of the present invention, and do not limit the patent scope of the present invention. Therefore, equivalent technical changes made by using the description and drawings of the present invention are included in the protection scope of the present invention. .

1‧‧‧film speaker

10‧‧‧ film substrate

101‧‧‧Surface

102‧‧‧Lower surface

11‧‧‧Working area

20‧‧‧conductive layer

30‧‧‧ring conductor

40‧‧‧conductive element

50‧‧‧Audio source signal output

Claims (8)

A film speaker, including: a film substrate, wherein the film substrate has opposite upper and lower sides, the film substrate is a polyvinylidene fluoride (PVDF) film, and the upper side of the film substrate is The lower side can respectively define a working area; two conductive layers, the two conductive layers are metal films or metal oxide films, the two conductive layers are arranged in a pattern on the opposite upper and lower sides of the film substrate, the The two conductive layers are closely attached to the upper side and the lower side of the film substrate, respectively, and at least cover the upper side and the lower side of the film substrate in the working area; two ring conductors, the two rings The conductors are respectively disposed on two opposite sides of the film substrate; the two ring-shaped conductors are opposed to each other and respectively surround the edge of the working area, and are respectively attached to the edges of the two conductive layers located at the periphery of the working area; and the two conductive Element, the two conductive elements are respectively disposed on one side of the two ring-shaped conductors relative to the film substrate, the two conductive elements are ring-shaped bodies corresponding to the two ring-shaped conductors, and cover and contact the two ring-shaped conductors Opposite to a side of the film substrate; the two conductive elements are respectively connected to the two poles of a sound source signal output, so that the sound source signal output by the sound source signal can be conducted to the two conductions through the two conductive elements and the two ring conductors Layer, so that the film substrate vibrates due to the inverse piezoelectric effect to emit sound, and the two conductive layers also vibrate together with the film substrate. The thin film speaker according to claim 1, wherein the two ring-shaped conductors are conductive adhesives or metal conductor layers disposed on the surfaces of the two conductive layers by electroplating. The film speaker according to claim 2, further comprising a frame structure, the frame structure is disposed at a position where the film substrate is located at the edge of the working area, so that It can be obtained that the film substrate forms a planar state within the working area. The thin film speaker according to claim 3, wherein the frame structure includes: a lower frame and an upper frame, the upper frame and the lower frame are disposed on the upper side of the edge of the working area of the film substrate opposite to the lower frame The lower side, and relatively sandwiched between the two ring-shaped conductors and the two conductive elements with respect to a side of the film substrate, for pressing the ring-shaped conductor and the two conductive elements into contact with the two conductive layers Outside. The thin film speaker according to claim 4, wherein the side of the lower frame facing the film substrate has a top surface, a slot is provided in the center of the top surface, and the side of the upper frame facing the film substrate has A bottom surface, the bottom mask has an engaging flange corresponding to the clamping slot, when the upper frame body and the lower frame body are relatively clamped, the clamping flange can be engaged in the clamping groove, and the film The base material corresponds to the material of the engaging flange and the position of the engaging groove and is pressed into the engaging groove, and the film base material is formed corresponding to the material of the engaging flange and the position of the engaging groove and the card Close the concave and convex shapes corresponding to the flange and the slot. The thin film speaker according to claim 2, wherein the thin film substrate can be attached to a surface of a plate body, and the thin film substrate is formed into a planar state through the plate body. The film speaker according to claim 2, wherein the film substrate is provided with at least one perforation within the working area. The thin film speaker according to claim 1, wherein the shape of the working area is selected from one of a circle, a rectangle, a triangle, an ellipse, and a polygon, or a combination thereof.

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