An electrostatic ultrasonic transducer

Abstract

This utility model discloses an electrostatic ultrasonic transducer, comprising a vibrating layer, a supporting structure, and a substrate layer. The supporting structure is disposed between the vibrating layer and the substrate layer, creating an air gap between them necessary for the vibrating layer to vibrate vertically. The vibrating layer includes a folded screen, and the substrate layer includes a bottom electrode layer and an insulating layer. The insulating layer is disposed on the upper surface of the bottom electrode layer near the vibrating layer. The supporting structure is disposed between the folded screen and the insulating layer. The folded screen and the substrate layer are fitted together. A driving voltage is applied between the folded screen and the substrate layer. Under the drive of the driving voltage, the vibrating layer emits sound directionally and displays simultaneously. This utility model uses an existing folded screen directly or indirectly as the diaphragm of the electrostatic ultrasonic transducer, facilitating the integration and processing of the folded screen and the electrostatic ultrasonic transducer.

Description

Technical Field

[0001] This utility model relates to the field of screen-oriented sound technology, specifically to an electrostatic ultrasonic transducer. Background Technology

[0002] While pursuing large screens and portability, foldable screen devices pose challenges to audio systems, as traditional speakers occupy a large space and are difficult to integrate into flexible screens. Parametric array speakers utilize the ultrasonic self-demodulation effect to achieve directional sound emission, and their core is a high-efficiency ultrasonic transducer.

[0003] Electrostatic ultrasonic transducers are suitable for use in parametric array loudspeakers due to their characteristics, but the mechanical stress during bending can easily damage the transducer structure. Therefore, how to integrate them with foldable screens and ensure their reliability in the bending area is a current technical challenge.

[0004] Therefore, it is crucial to develop an electrostatic ultrasonic transducer structure that can be integrated with foldable screens and is resistant to bending. Utility Model Content

[0005] The purpose of this invention is to provide an electrostatic ultrasonic transducer that can be combined with a foldable screen.

[0006] To achieve the above objectives, this utility model proposes an electrostatic ultrasonic transducer, comprising a vibrating layer, a supporting structure, and a substrate layer. The supporting structure is disposed between the vibrating layer and the substrate layer, forming an air gap between them necessary for the vibrating layer to vibrate vertically. The vibrating layer includes a folded screen, and the substrate layer includes a bottom electrode layer and an insulating layer. The insulating layer is disposed on the upper surface of the bottom electrode layer near the vibrating layer. The supporting structure is disposed between the folded screen and the insulating layer. The folded screen is in contact with the substrate layer. A driving voltage is applied between the folded screen and the substrate layer. The vibrating layer emits sound directionally and displays simultaneously under the drive of the driving voltage.

[0007] In a preferred embodiment, the foldable screen includes a foldable screen stack and a first conductive base plate, the first conductive base plate being disposed on the lower end surface of the foldable screen stack near the substrate layer, and the first conductive base plate being reused as the top electrode layer of the vibration layer.

[0008] In a preferred embodiment, an adhesive layer is further included between the foldable screen stack and the top electrode layer.

[0009] In a preferred embodiment, the foldable screen stack is an OLED screen, the first conductive substrate is a SUS stainless steel plate, and the adhesive layer is a pressure-sensitive adhesive layer.

[0010] In a preferred embodiment, the vibration layer further includes a top electrode layer disposed on the lower end surface of the foldable screen near the substrate layer; and / or, the foldable screen is an OLED screen.

[0011] In a preferred embodiment, the bottom electrode layer is a second conductive substrate.

[0012] In a preferred embodiment, the substrate layer is divided into multiple functional areas and at least one non-functional area. Each pair of adjacent functional areas is separated by the non-functional area. The multiple functional areas and the at least one non-functional area share the vibration layer. Each functional area and the vibration layer form a directional sound-emitting display area, and each non-functional area and the vibration layer form a bending area.

[0013] In a preferred embodiment, each functional area includes the bottom electrode layer and an insulating layer, and the support structure is provided between the functional area and the vibration layer; each non-functional area does not have the bottom electrode layer and the insulating layer, and the support structure is not provided between the non-functional area and the vibration layer.

[0014] In a preferred embodiment, each of the directional sound-emitting display areas is independently loaded with the driving voltage, and the multiple directional sound-emitting display areas are driven synchronously or independently.

[0015] In a preferred embodiment, a driving voltage is applied between the upper and lower electrodes of each of the directional sound-emitting display areas.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. This utility model uses the existing folding screen directly as the diaphragm of the electrostatic ultrasonic transducer, or adds an electrode layer to the existing folding screen. This facilitates the integration and processing of the folding screen and the electrostatic ultrasonic transducer, significantly saves internal space, makes it possible to achieve parametric array directional sound generation on the folding screen device, and provides a brand-new experience such as private listening while folding the display.

[0018] 2. This utility model effectively solves the problem of stress concentration during bending by using special designs such as partitioning the substrate layer and not setting up support structures in the bending area, thereby improving the reliability and durability of the product. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of an electrostatic ultrasonic transducer according to one embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of an electrostatic ultrasonic transducer according to another alternative embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the electrostatic ultrasonic transducer of the present invention, which uses an existing OLED screen as the vibration layer;

[0022] Figure 4 This is a schematic diagram of the stacked structure of the electrostatic ultrasonic transducer of this utility model, which is divided into multiple directional sound-emitting display areas and bending areas.

[0023] Figure 5 This is a schematic diagram of the electrostatic ultrasonic transducer of this utility model, which is divided into multiple directional sound emission and display areas and bending areas.

[0024] The attached figures are labeled as follows:

[0025] 1. Vibration layer; 10. Folding screen; 11. Folding screen stack; 12. First conductive base plate; 13. Adhesive layer; 14. Top electrode layer; 2. Support structure; 3. Substrate layer; 31. Bottom electrode layer; 32. Insulating layer; 4. Air gap; 5. Directional sound display area; 6. Bending area; 7. Functional area; 8. Non-functional area. Detailed Implementation

[0026] The specific embodiments of this utility model are described in detail below, but it should be understood that the protection scope of this utility model is not limited to the specific embodiments.

[0027] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0028] This invention aims to provide an innovative electrostatic ultrasonic transducer structure to solve the integration challenge of acoustic modules with foldable screen devices. This structure can be integrated seamlessly with a foldable screen, simplifying design and saving space by utilizing the screen's structural features, while ensuring mechanical reliability under repeated bending, achieving efficient and stable ultrasonic radiation.

[0029] Combination Figure 1 and Figure 2 As shown, the electrostatic ultrasonic transducer disclosed in this utility model includes a vibration layer 1, a support structure 2, and a substrate layer 3. The vibration layer 1 is directly implemented using an existing folding screen, or a conductive layer is added to an existing folding screen to serve as the vibration layer 1.

[0030] Specifically, such as Figure 1As shown, in one embodiment, the vibration layer 1 includes a foldable screen 10, which includes a foldable screen stack 11 and a first conductive base plate 12. The first conductive base plate 12 is disposed on the lower end surface of the foldable screen stack 11 near the substrate layer 3, and the first conductive base plate 12 is reused as the top electrode layer 14 of the vibration layer 1. In implementation, the foldable screen 10 can be directly implemented using a commercially available, relatively mature OLED screen. Combined with... Figure 3 As shown, in one specific embodiment, the OLED screen includes, from top to bottom, a first PET (polyethylene terephthalate) layer, a first OCA (optical transparent adhesive) layer, a UTG (ultra-thin flexible glass) layer, a second OCA layer, an OLED display panel, a first PSA (pressure-sensitive adhesive) layer, a second PET layer, a second PSA layer, a PI (polyimide) layer, a third PSA layer, and a first SUS (stainless steel plate) layer. The structure above the third PSA layer serves as the aforementioned foldable screen stack 11, the first SUS layer serves as the aforementioned first conductive substrate 12, and the third PSA layer between the foldable screen stack 11 and the first SUS layer 12 serves as the adhesive layer 13 between the foldable screen stack 11 and the first conductive substrate 12. This embodiment directly uses the existing foldable screen 10 as the vibration layer 1 of the electrostatic ultrasonic transducer. Of course, in other alternative embodiments, the foldable screen 10 is not limited to the structure defined in this specific embodiment; it can also be implemented using other commercially available OLED screen or other display screen structures (such as LED screens).

[0031] In another alternative embodiment, such as Figure 2 As shown, the vibration layer 1 includes a folded screen 10 and a top electrode layer 14, wherein the top electrode layer 14 is disposed on the lower end surface of the folded screen 10 near the substrate layer 3. In this embodiment, the folded screen 10 can also be implemented using the existing OLED screen described above, and the specific structure is described above and will not be repeated here. Unlike the above embodiment, this embodiment adds a top electrode layer 14 below the existing folded screen 10 to serve as the vibration layer 1 of the electrostatic ultrasonic transducer. In practice, the material of the top electrode layer 14 can be, for example, ITO (indium tin oxide), graphene, silver nanowires, metal mesh, conductive polymers (such as PEDOT:PSS, a conductive polymer composite material composed of poly(3,4-ethylenedioxythiophene) / poly(p-phenylene sulfonic acid)), etc. In addition, the thickness and structure of each layer of the folded screen 10 and the thickness of the added top electrode layer 14 can be achieved according to actual acoustic requirements and are not limited here.

[0032] The substrate layer 3 specifically includes a bottom electrode layer 31 and an insulating layer 32, wherein the insulating layer 32 is disposed on the upper surface of the bottom electrode layer 31 near the vibrating layer 1. In practice, the bottom electrode layer 31 can also be implemented using a second conductive substrate, such as a stainless steel plate (SUS). The insulating layer 32 can be made of OC (photoresist), printing ink, or SiN. x It can be achieved using silicon nitride, SiOx (silicon oxide), PTFE (polytetrafluoroethylene), PVDF (polyvinylidene fluoride), PI (polyimide) or Parylene (poly(p-xylene)).

[0033] The support structure 2 is disposed between the vibrating layer 1 and the substrate layer 3, creating an air gap 4 between them necessary for the vibrating layer 1 to vibrate vertically. In practice, the support structure 2 can be formed on the vibrating layer 1 or on the substrate layer 3, preferably on the substrate layer 3, specifically on the upper surface of the insulating layer 32 near the vibrating layer 1. The support structure 2 can be implemented as an array of support points / columns of a certain thickness, and its material can be selected from OC adhesive, printing ink, or SiN. x SiO x Materials include PTFE, PVDF, PI, or SU-8 photoresist. Furthermore, the height of the support structure 2 and the spacing between adjacent support structures 2 can be determined according to actual acoustic requirements and are not limited here.

[0034] During operation, a driving voltage is applied between the top electrode layer 14 of the vibration layer 1 and the bottom electrode layer 31 of the substrate layer 3. The driving voltage can be an AC voltage Vac or a combination of a DC bias voltage Vdc and an AC voltage Vac. The changing electrostatic force drives the vibration layer 1 to generate high-frequency vibration. The radiated ultrasonic waves are nonlinearly demodulated in the air to form audible directional sound.

[0035] Preferably, according to the folding requirements, the above-mentioned electrostatic ultrasonic transducer can be partitioned, into multiple directional sound emission and display areas 5 and bending areas 6. Combined with... Figure 4 and Figure 5As shown, in a specific embodiment, the substrate layer 3 is preferably partitioned, specifically into multiple functional areas 7 and at least one non-functional area 8. Each pair of adjacent functional areas 7 is separated by a non-functional area 8. The multiple functional areas 7 and at least one non-functional area 8 share a vibration layer 1, and each functional area 7 and the vibration layer 1 form the aforementioned directional sound-emitting display area 5. Each non-functional area 8 and the vibration layer 1 form the aforementioned bending area 6. Specifically, the bottom electrode layer 31 and the insulating layer 32 of the substrate layer 3 are physically cut at the bending area 6, dividing them into multiple independent parts, which can release mechanical stress. In a specific embodiment, the functional areas 7 of the substrate layer 3 normally form the aforementioned functional structure, i.e., including the aforementioned bottom electrode layer 31 and insulating layer 32, and the aforementioned support structure 2 is also provided between the functional areas 7 and the vibration layer 1. However, the non-functional areas 8 of the substrate layer 3 do not have the aforementioned functional structure; that is, each non-functional area 8 does not have the aforementioned bottom electrode layer 31 and insulating layer 32, and the aforementioned support structure 2 is not provided between the non-functional areas 8 and the vibration layer 1. By omitting these functional structures (including the bottom electrode layer 31, insulating layer 32, and support structure 2) in the bending region 6, damage to the device due to stress concentration during folding can be avoided. The directional sound-emitting display region 5 has the support structure 2 normally arranged to maintain the air gap 4. Specifically, during the fabrication of the substrate layer 3, the bottom electrode layer 31 is cut and separated at the bending region 6. Then, an insulating layer 32 is formed on the separated bottom electrode layer 31, and a support pillar array is fabricated, but no support pillars are provided in the bending region 6. Afterwards, the vibrating layer 1, which includes the OLED, PSA, and top electrode layer, is aligned and bonded to the substrate layer 3 (specifically, the frame is bonded). When folded, because the bottom electrode layer 31 in the bending region is disconnected and there are no support pillars, this structure can smoothly bend with the screen, effectively releasing stress and ensuring device reliability.

[0036] In addition, preferably, each directional sound-emitting display area 5 (specifically between the top electrode layer of the vibration layer 1 and the bottom electrode layer 31 of the substrate layer 3) is independently loaded with the above-mentioned driving voltage, and multiple directional sound-emitting display areas 5 can be driven synchronously or independently, which facilitates synchronous or independent sound field control.

[0037] The advantages of this utility model are as follows: 1. This utility model uses an existing folding screen directly as the diaphragm of an electrostatic ultrasonic transducer, or adds an electrode layer to an existing folding screen, which facilitates the integration and processing of the folding screen and the electrostatic ultrasonic transducer, significantly saving internal space and making it possible to achieve parametric array directional sound generation on a folding screen device. It also provides a new experience such as private listening while displaying the device. 2. This utility model effectively solves the stress concentration problem during bending through special designs such as partitioning the substrate layer and not setting support structures in the bending area, thus improving the reliability and durability of the product.

[0038] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the present invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the present invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the present invention, as well as various different choices and variations. The scope of the present invention is intended to be defined by the claims and their equivalents.

Claims

1. An electrostatic ultrasonic transducer, characterized in that, The device includes a vibrating layer, a supporting structure, and a substrate layer. The supporting structure is disposed between the vibrating layer and the substrate layer, creating an air gap between them necessary for the vibrating layer to vibrate vertically. The vibrating layer includes a foldable screen. The substrate layer includes a bottom electrode layer and an insulating layer. The insulating layer is disposed on the upper surface of the bottom electrode layer near the vibrating layer. The supporting structure is disposed between the foldable screen and the insulating layer. The foldable screen is in contact with the substrate layer. A driving voltage is applied between the foldable screen and the substrate layer. The vibrating layer emits sound directionally and displays simultaneously under the drive of the driving voltage.

2. The electrostatic ultrasonic transducer as described in claim 1, characterized in that, The foldable screen includes a foldable screen stack and a first conductive base plate. The first conductive base plate is disposed on the lower end surface of the foldable screen stack near the substrate layer, and the first conductive base plate is reused as the top electrode layer of the vibration layer.

3. The electrostatic ultrasonic transducer as described in claim 2, characterized in that, An adhesive layer is also included between the foldable screen stack and the top electrode layer.

4. The electrostatic ultrasonic transducer as described in claim 3, characterized in that, The foldable screen is an OLED screen, the first conductive substrate is a SUS stainless steel plate, and the adhesive layer is a pressure-sensitive adhesive layer.

5. An electrostatic ultrasonic transducer as described in claim 1, characterized in that, The vibration layer further includes a top electrode layer, which is disposed on the lower end surface of the foldable screen near the substrate layer; and / or, the foldable screen is an OLED screen.

6. An electrostatic ultrasonic transducer as described in any one of claims 1 to 5, characterized in that, The bottom electrode layer is a second conductive substrate.

7. An electrostatic ultrasonic transducer as described in claim 1, characterized in that, The substrate layer is divided into multiple functional areas and at least one non-functional area. Each pair of adjacent functional areas is separated by the non-functional area. The multiple functional areas and the at least one non-functional area share the vibration layer. Each functional area and the vibration layer form a directional sound display area, and each non-functional area and the vibration layer form a bending area.

8. An electrostatic ultrasonic transducer as described in claim 7, characterized in that, Each functional area includes the bottom electrode layer and the insulating layer, and the supporting structure is provided between the functional area and the vibration layer; each non-functional area does not have the bottom electrode layer and the insulating layer, and the supporting structure is not provided between the non-functional area and the vibration layer.

9. An electrostatic ultrasonic transducer as described in claim 8, characterized in that, Each of the directional sound-emitting display areas is independently loaded with the driving voltage, and the multiple directional sound-emitting display areas are driven synchronously or independently.

10. An electrostatic ultrasonic transducer as described in claim 9, characterized in that, A driving voltage is applied between the upper and lower electrodes of each of the directional sound-emitting display areas.

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