A directional sound-emitting folding display screen

Abstract

This invention discloses a directional sound-emitting foldable display screen, comprising a vibrating layer and a non-vibrating layer. The vibrating layer includes a foldable screen and a vibrating substrate layer, which is integrally formed using 3D printing and disposed on the lower end surface of the foldable screen away from the user. The non-vibrating layer includes a non-vibrating substrate layer, an insulating layer, and a micro-patterned layer. The insulating layer is disposed on the upper end surface of the non-vibrating substrate layer near the vibrating layer. The micro-patterned layer consists of multiple insulating bumps formed on the upper end surface of the insulating layer near the vibrating layer, and is integrally formed by using 3D printing, slot coating, or exposure and development processes to form a resin layer internally doped with alumina nanoparticles. This invention achieves full foldability of the directional sound-emitting foldable display screen while improving the overall operational reliability of the product, and has advantages such as significantly shortened development cycle, lower cost, wider applicability, and higher precision and flexibility.

Description

Technical Field

[0001] This invention relates to the field of directional sound technology for screens, and more specifically to a directional sound folding display screen. Background Technology

[0002] With the development of display technology, consumers are not only demanding high-quality and clear images from display devices, but are also increasingly focusing on sound output effects. They tend to prefer display devices that can achieve perfect integration of sound and image, seamlessly blending the displayed image with the played sound.

[0003] Existing technologies for achieving sound and image integration in display devices utilize screen-based sound generation technology. The principle behind this is to use vibrating elements to drive the screen to vibrate and produce sound. For example, a resonant screen-based sound generation solution involves attaching a vibrating device to the bottom of the screen or the frame of the device. When the device operates, it vibrates, ultimately causing the screen to vibrate and produce sound. Another example is a direct-drive screen-based sound generation solution, where the device consists of two parts: one part is directly attached to the screen, and the other part is fixed to the frame. When the device operates, the two parts generate mutual attraction or repulsion, thereby driving the screen to vibrate and produce sound. Compared to the resonant screen-based sound generation solution, this method offers improved conversion efficiency.

[0004] When electronic devices feature foldable displays, the area available for display can be significantly increased, providing users with a better visual experience. Foldable displays are increasingly being used in various types of terminal devices and show great promise.

[0005] In other words, the market demand for foldable screens is becoming increasingly clear. Therefore, how to make directional sound-emitting screens foldable so as to better integrate with foldable displays is a problem that needs to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide a directional sound-emitting folding display screen that combines a folding screen with a directional sound-emitting screen.

[0007] To achieve the above objectives, the present invention proposes a directional sound-emitting folding display screen, comprising:

[0008] The display screen comprises a vibrating layer, a non-vibrating layer, and a micro-patterned layer located between the vibrating layer and the non-vibrating layer. The edges of the vibrating layer and the non-vibrating layer are attached together, and an air gap is formed between them through the micro-patterned layer. The vibrating layer vibrates and emits sound in a direction closer to or farther from the non-vibrating layer under the action of an externally applied ultrasonic signal. The directional sound-emitting folding display screen includes a plurality of functional parts distributed along a first direction and at least one folding part. Each pair of adjacent functional parts is connected by a folding part. The functional parts are folded away from or closer to the client so that the adjacent functional parts are stacked on top of each other in a second direction.

[0009] The vibration layer includes a folding screen and a vibration substrate layer. The vibration substrate layer is integrally formed using 3D printing technology and is disposed on the lower end surface of the folding screen away from the client. The non-vibration layer includes a non-vibration substrate layer, an insulating layer, and the micro-pattern layer. The insulating layer is disposed on the upper end surface of the non-vibration substrate layer near the vibration layer. The micro-pattern layer consists of multiple insulating bumps formed on the upper end surface of the insulating layer near the vibration layer, and it is integrally formed by using 3D printing, slot coating, or exposure and development technology to form a resin layer doped with alumina nanoparticles.

[0010] In a preferred embodiment, the vibrating substrate layer is a SUS steel plate or a carbon fiber plate, and / or the doping concentration of the alumina nanoparticles ranges from 1% to 15%.

[0011] In a preferred embodiment, each insulating bump contains at least one alumina nanoparticle, and the diameter of the alumina nanoparticle is 16µm~20µm or 1µm~10µm.

[0012] In a preferred embodiment, a breathable structure communicating with the outside is provided on the non-vibration layer located in the fold. The breathable structure includes at least one vent penetrating the non-vibration layer to connect the air gap and the outside, and a waterproof and breathable membrane. The waterproof and breathable membrane covers the end of the vent that is away from the vibration layer; and / or, the pore size of the vent is 100um to 500um.

[0013] In a preferred embodiment, the edge of the vibrating substrate layer is bonded to the edge of the insulating layer by a waterproof sealing structure, the waterproof sealing structure comprising a hot-pressed waterproof strip or comprising a hot-pressed waterproof strip and a side-sealing waterproof adhesive; the side-sealing waterproof adhesive is sealed to the outside of the hot-pressed waterproof strip.

[0014] In a preferred embodiment, the foldable screen includes a screen assembly and a protective assembly, the screen assembly being located between the protective assembly and the vibration substrate layer; the screen assembly includes an OLED screen or the screen assembly includes, from top to bottom, a first OCA optical adhesive, a polarizer layer with pressure-sensitive adhesive, an OLED screen, and a second OCA optical adhesive, the upper surface of the screen assembly being bonded to the protective assembly via the first OCA optical adhesive, and the lower surface being bonded to the vibration substrate layer via the second OCA optical adhesive; and / or, the protective assembly includes, from top to bottom, a scratch-resistant layer, a stress buffer layer, and a foldable substrate layer, or the protective assembly includes, from top to bottom, an optical layer, a scratch-resistant layer, a stress buffer layer, and a foldable substrate layer, stacked sequentially; and / or, the scratch-resistant layer is an alumina nanoparticle scratch-resistant layer; and / or, the thickness of the scratch-resistant layer is less than 5 μm.

[0015] In a preferred embodiment, the vibrating substrate layer is integrally formed with multiple openings by 3D printing. The openings are either through holes or blind holes that are recessed from the lower end of the vibrating substrate layer towards its upper end. The openings correspond to the insulating protrusions of the micropatterned layer. After the edges of the vibrating layer and the non-vibrating layer are attached, the insulating protrusions of the micropatterned layer are embedded and fixed into the openings, forming the air gap between them and the top of the openings; and / or, the openings are arranged in a honeycomb pattern.

[0016] In a preferred embodiment, the non-vibration substrate layer is any one of SUS steel plate, carbon fiber plate, CPI layer, PET layer, UTG, and UFG.

[0017] In a preferred embodiment, when the vibrating substrate layer and the non-vibrating substrate layer are the carbon fiber plate, a composite metal layer is further disposed on the surface of the vibrating substrate layer and the non-vibrating substrate layer, the thickness of the composite metal layer is less than 3 μm, and its sheet resistance is not higher than 10 ohms.

[0018] In a preferred embodiment, the end faces of the folded substrate layer, the vibrating substrate layer, and the non-vibrating substrate layer located at the fold and close to the client are thinned to form a folded groove recessed in the direction away from the client; and / or, the opening size of the folded groove is 5um to 8um.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. This invention provides a novel directional sound-emitting screen integrated under an OLED foldable screen, forming a new type of directional sound-emitting foldable display screen combining a directional sound-emitting screen and an OLED foldable screen. Through improvements in the materials, processing technology, and structural design of the vibration substrate layer, as well as innovative designs for the materials and processing technology of the micro-pattern layer, the directional sound-emitting foldable display screen achieves full foldability while improving the overall operational reliability of the product. Furthermore, the innovative use of 3D printing technology significantly shortens the development cycle and offers advantages such as lower cost, wider applicability, and higher precision and flexibility.

[0021] 2. The invention innovatively adds a scratch-resistant layer to the protective components of the original OLED foldable screen, which can significantly improve the scratch and wear resistance of the final product, thereby improving its operational reliability.

[0022] 3. The present invention ingeniously adds a breathable structure to the folded part of the non-vibration layer to ensure the air pressure balance inside and outside the screen, avoiding the problems of easy deformation of the vibration layer, detachment of the adhesive layer of the micro-pattern layer, resulting in changes in the frequency capacitance of the finished product and reduced reliability.

[0023] 4. This invention replaces the existing inner ring adhesive method with a hot-pressed waterproof adhesive strip for frame fixing. It is suitable for narrow bezel areas of existing displays with a thickness of less than 1mm. It will not cause adhesive overflow and can also ensure the bonding stability between the vibrating layer and the non-vibrating layer, thereby ensuring the reliability of the product. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a directional sound-emitting folding display screen (with blind holes and the vibrating layer and non-vibrating layer not attached) in one embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of a directional sound-emitting folding display screen (with through holes and the vibrating layer and non-vibrating layer not attached) in another embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the structure of a directional sound-emitting folding display screen (with through holes and the vibrating layer and non-vibrating layer bonded together) in another embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the honeycomb structure of the present invention;

[0028] Figure 5 This is a schematic flowchart illustrating the manufacturing process of the directional sound-emitting foldable display screen of the present invention.

[0029] The attached figures are labeled as follows:

[0030] 1. Vibration layer; 11. Foldable screen; 111. Protective component; 1111. Foldable substrate layer; 1112. Stress buffer layer; 1113. Scratch-resistant layer; 1114. Optical layer; 112. Screen assembly; 1121. OLED screen; 1122. First OCA optical adhesive; 1123. Polarizing film layer; 1124. Second OCA optical adhesive; 12. Vibration substrate layer; 121. Opening; 2. Non-vibration layer; 21. Non-vibration substrate layer; 22. Insulating layer; 3. Micro-pattern layer; 4. Air gap; 5. First folding groove; 6. Second folding groove; 7. Third folding groove; 8. Breathable structure; 81. Breathing hole; 82. Waterproof and breathable membrane; 9. Waterproof sealing structure; 91. Hot-pressed waterproof strip; 92. Side sealing waterproof adhesive; 10. Functional part; 20. Folding part; 30. Flexible circuit board. Detailed Implementation

[0031] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0032] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprising" shall be understood to include the stated elements or components without excluding other elements or other components.

[0033] Combination Figures 1-3 As shown, the present invention discloses a directional sound-emitting foldable display screen, comprising a vibrating layer 1, a non-vibrating layer 2, and a micro-patterned layer 3 located between the vibrating layer 1 and the non-vibrating layer 2. The edges of the vibrating layer 1 and the non-vibrating layer 2 are attached together, and an air gap 4 is formed between them through the micro-patterned layer 3. Under the action of an externally applied ultrasonic signal, the vibrating layer 1 vibrates in a direction closer to or farther from the non-vibrating layer 2 to generate sound. Furthermore, the above-mentioned directional sound-emitting foldable display screen is foldable, and it is divided into sections along a first direction (e.g., ...). Figure 1 A plurality of functional parts 10 and at least one folding part 20 are distributed in a horizontal direction, wherein each pair of adjacent functional parts 10 is connected by a folding part 20, and the functional parts 10 are folded away from or towards the client to the adjacent functional parts 10 in a second direction (e.g., in the horizontal direction). Figure 1 (Center and rear directions) Layered settings.

[0034] Specifically, in this embodiment, the vibration layer 1 includes a folding screen 11 and a vibration substrate layer 12, wherein the vibration substrate layer 12 is disposed on the lower end surface of the folding screen 11 away from the client, that is, the directional sound-generating structure of the present invention is located under the screen (i.e., the folding screen 11). In a specific embodiment, the folding screen 11 specifically includes a protective component 111 and a screen assembly 112, wherein the protective component 111 is located on the outer side of the screen assembly 112 near the client, and is used to protect the screen assembly 112.

[0035] In implementation, the protective component 111 includes a folded substrate layer 1111, a stress buffer layer 1112, and a scratch-resistant layer 1113 stacked sequentially from bottom to top; or the protective component 111 includes a folded substrate layer 1111, a stress buffer layer 1112, a scratch-resistant layer 1113, and an optical layer 1114 stacked sequentially from bottom to top. Preferably, the folded substrate layer 1111 is made of UFG (uneven thickness flexible glass) material, and the portion located at the folded portion 20 is thinned to form a first folding groove 5 recessed in a direction away from the client (i.e., downward). Alternatively, if the folding is in a direction away from the client, the first folding groove 5 is formed in a direction closer to the client (i.e., downward). In implementation, the overall thickness of the folded substrate layer 1111 can be 30µm to 100µm, with different thicknesses selected depending on the design of the folded radius (R-angle). For example, when the thickness of the folded substrate layer 1111 is 30µm, the R-angle can be 1mm; when the thickness is 100µm, the R-angle can be 4mm. The depth of the first folding groove 5 is preferably 30µm to 70µm, and the opening size is 5µm to 8µm, again with different depths and opening sizes selected based on the design of the folded radius (R-angle). During processing, the folded substrate layer 1111 can be formed from UFG raw material after thinning, edge grinding, and strengthening of the folded portion. In other alternative embodiments, the folded substrate layer 1111 can also be made of UTG (ultra-thin flexible glass) material.

[0036] The stress buffer layer 1112 is used to prevent the folded substrate layer 1111 from cracking. Its thickness is preferably less than 20 μm, with a minimum of 2 μm to 4 μm and a maximum of 10 to 20 μm. It can be processed onto the upper surface of the folded substrate layer 1111 by 3D printing or slot coating, and can be cured by UV curing, thermosetting, or UV + thermosetting dual curing after processing. The specific material can be selected from the existing buffer layer material on OLED screens.

[0037] The scratch-resistant layer 1113 is a protective layer added to this invention and is one of its innovative features. The surface hardness of the existing integrally 3D-molded stress buffer layer 1112 can reach 750g / 3H, but its abrasion resistance is insufficient. Therefore, in one solution, a nano-scale alumina coating is innovatively added to the surface of the stress buffer layer 1112, i.e., the scratch-resistant layer 1113 is an alumina nanoparticle scratch-resistant layer with a thickness of less than 5µm, preferably 3µm to 5µm, with different thicknesses depending on the processing technology. The high hardness (Mohs hardness 9) of the nano-alumina significantly improves the scratch and wear resistance of the stress buffer layer 1112. During processing, the nano-alumina can be formed on the upper surface of the stress buffer layer 1112 using 3D printing or slot coating technology.

[0038] The optical layer 1114 is located on the outermost layer and its thickness is generally 1µm to 2µm. In practice, it can be one or a combination of two or more of the following: anti-glare (AG), anti-reflective (AR), and anti-fingerprint (AF). Of course, this layer can be included or omitted depending on actual needs. During processing, the optical layer 1114 can be formed on the upper surface of the aforementioned scratch-resistant layer 1113 using 3D printing or slot coating technology.

[0039] Furthermore, the aforementioned protective component 111 is preferably processed at a low temperature of less than 280°C to prevent the UFG glass from cracking due to uneven stress in a high-temperature environment.

[0040] The screen assembly 112 is located between the protective assembly 111 and the vibration substrate layer 12. In one specific embodiment, it specifically includes an OLED screen 1121, with its upper surface bonded to the folded substrate layer 1111 and its lower surface bonded to the vibration substrate layer 12. Alternatively, in another specific embodiment, the screen assembly 112 includes, from top to bottom, a first OCA optical adhesive 1122, a polarizer layer (PSA+POL) 1123 with pressure-sensitive adhesive, an OLED screen 1121, and a second OCA optical adhesive 1124. The upper surface of the screen assembly 112 is bonded to the folded substrate layer 1111 of the protective assembly 111 via the first OCA optical adhesive 1122, and the lower surface is bonded to the vibration substrate layer 12 via the second OCA optical adhesive 1124. In implementation, the thickness of the OLED screen 1121 is less than 50 μm, the thickness of the polarizing layer 1123 is less than 80 μm, and the thicknesses of the first OCA optical adhesive 1122 and the second OCA optical adhesive 1124 are both less than 25 μm. Of course, in other alternative embodiments, the screen assembly 112 can also be other OLED screen assembly structures, i.e., not limited to the OLED screen structure defined herein. During processing, the OLED screen 1121 is first bonded to the second OCA optical adhesive 1124, and after bonding, a degassing treatment is preferably performed to form component A; the roll of raw material with pressure-sensitive adhesive polarizing film layer 1123 is cut into sheets and the first OCA optical adhesive 1122 is bonded to its surface to form component B; component A and component B are bonded together (specifically, the upper end of the OLED screen 1121 of component A is bonded to the lower end of the polarizing film layer 1123 with pressure-sensitive adhesive of component B), and after bonding, it is bonded to the folded substrate layer 1111 of the above-mentioned protective component 111, and after bonding, a degassing treatment is preferably performed.

[0041] Unlike existing directional sound-emitting screens where the vibration substrate layer 12 is made of materials such as CPI (transparent polyimide) or PET (polyethylene terephthalate), the vibration substrate layer 12 of this invention is preferably made of SUS steel plate or carbon fiber plate. These materials possess extremely high tensile strength and rigidity, are not prone to plastic deformation during repeated folding, and can maintain structural stability over a long period. Furthermore, they also exhibit high-temperature resistance (typically exceeding 300°C), surface hardness, scratch resistance, and long-term reliability. In addition to the different materials, the processing technology of the vibration substrate layer 12 of this invention also differs. In practice, it can be integrally formed using 3D printing, slot coating, or exposure and development processes. 3D printing is preferred, with a Z-direction accuracy of ±2µm. Preferably, in one specific embodiment, the vibration substrate layer 12 is integrally formed with multiple openings 121 by 3D printing, with a positional accuracy of ±10µm and an XY repeatability accuracy of ±10µm. In implementation, these openings 121 are through holes, meaning they penetrate both the upper and lower surfaces of the vibrating substrate layer 12, or they can be blind holes, meaning they do not penetrate the vibrating substrate layer 12 but are formed by recesses from the lower end of the vibrating substrate layer 12 towards its upper end surface. Through holes are preferred. These openings are used for embedding and fixing the micropatterned layer 3 described below. In implementation, the overall thickness of the vibrating substrate layer 12 is less than 25 μm. If the openings 121 on the vibrating substrate layer 12 are through holes, the depth of the through holes is the same as the thickness of the vibrating substrate layer 12, i.e., less than 25 μm; if the openings 121 are blind holes, the overall thickness of the vibrating substrate layer 12 is less than 25 μm, and the depth of the blind holes is less than 10 μm. Additionally, to increase structural strength, such as... Figure 4 As shown, the arrangement of the openings 121 is preferably honeycomb-shaped, that is, each opening 121 is hexagonal, and multiple hexagonal openings 121 are arranged in combination. Furthermore, corresponding to the folded substrate layer 1111, the end face of the vibrating substrate layer 12 located in the folded portion 20 and close to the client is also thinned to form a second folded groove 6 recessed in the direction away from the client. In practice, the depth of the second folded groove 6 on the vibrating substrate layer 12 is preferably less than 15 μm, and the opening size is preferably 5 μm to 8 μm. Additionally, since the vibrating substrate layer 12 located in the folded portion 20 has been thinned, the openings 121 on the vibrating substrate layer 12 located in the folded portion 20 are preferably through holes.

[0042] After the upper surface of the vibrating substrate layer 12 is bonded to the folding screen 11, it is preferably subjected to a degassing treatment to form the vibrating layer 1. In practice, the overall thickness of the vibrating layer 1 is preferably between 250um ± 10um and 320um ± 10um, that is, its minimum thickness is 240um, 250um or 260um, and its maximum thickness is 310um, 320um or 330um.

[0043] The non-vibration layer 2 specifically includes a non-vibration substrate layer 21, an insulating layer 22, and the aforementioned micro-patterned layer 3. The non-vibration substrate layer 21 is located at the bottom and has a thickness of less than 30 μm. Corresponding to the aforementioned folded substrate layer 1111 and vibrating substrate layer 12, its end face near the client side of the folded portion 20 is also thinned to form a third folded groove 7 recessed away from the client. The opening size of the third folded groove 7 is also 5 μm to 8 μm. In practice, the non-vibration substrate layer 21 can be made of opaque SUS steel plate or carbon fiber plate, or transparent CPI, PET, UTG, or UFG, etc., preferably SUS steel plate or carbon fiber plate. If it is SUS steel plate or carbon fiber plate, it is the same as the vibrating substrate layer 12, preferably integrally formed using 3D printing, slot coating, or exposure and development processes, with 3D printing being the most preferred method.

[0044] An insulating layer 22 is disposed on the upper surface of the non-vibrating substrate layer 21 near the vibrating layer 1. During processing, it can be formed on the non-vibrating substrate layer 21 by printing, screen printing or coating, and its thickness is 6um~12um.

[0045] A micropatterned layer 3 is formed on the upper surface of the insulating layer 22 near the vibrating layer 1. Specifically, it consists of multiple insulating bumps or multiple insulating bumps arranged in an array, dividing the functional unit 10 into multiple vibrating units arranged in an array. The shape, position, and number of the insulating bumps correspond to the shape, position, and number of openings on the vibrating substrate layer 12. Generally, one insulating bump corresponds to one opening 121. The height of the insulating bump is less than the depth of the opening 121, so that after the insulating bump is embedded and fixed into the opening 121, an air gap 4 can be formed between its top and the top of the opening 121. In practice, the height of the insulating bump is 1µm to 10µm or 16µm to 20µm.

[0046] Preferably, unlike existing micropatterned layer 3 materials, the micropatterned layer 3 of this invention is made of resin internally doped with alumina nanoparticles. In practice, the diameter of the alumina nanoparticles varies depending on the design, preferably 16µm~20µm or 1µm~10µm; and the doping amount of the alumina nanoparticles needs to be determined according to the type of resin used to encapsulate them, ensuring that each insulating bump contains at least one alumina nanoparticle, with a doping concentration preferably between 1% and 15%. Compared to existing doped silica particles and / or plastic spheres, the alumina particles doped in this invention have a Mohs hardness between 9 and 10, while silica has a hardness between 6 and 7, making silica softer; and the Shore hardness of alumina is between D90 and D100, while silica is around A70. This high hardness doping helps the micropatterned layer 3 maintain its original height, improving its reliability, thereby ensuring that the frequency and capacitance of the directional sound-emitting folding display screen are within the design range, thus ensuring sound pressure stability. In addition, since the existing doped silicon dioxide will cause the micropattern layer 3 to have a certain polarization, the polarization will generate an additional reverse electric field in the micropattern layer 3, which will reduce the effective voltage between the electrodes of the directional sound-emitting folding display and thus reduce the sound pressure.

[0047] Furthermore, the micropatterned layer 3 can be fabricated using 3D printing, slot coating, or exposure and development processes, with 3D printing being the preferred method. Specifically, the processing method of the resin encapsulating the alumina nanoparticles and the micropatterned layer 3 can vary depending on the material of the non-vibrating substrate layer 21. Specifically, if the non-vibrating substrate layer 21 is made of opaque SUS steel plate or carbon fiber plate, the resin is preferably a low-viscosity resin (e.g., viscosity below 10 cps), and the micropatterned layer 3 is preferably fabricated by photopolymerization after 3D printing. This resin has a certain degree of adhesion, ensuring that the insulating protrusions are embedded and fixed into the opening 121, thus firmly locking the non-vibrating layer 2 and the vibrating layer 1 together. If the non-vibrating substrate layer 21 is made of transparent CPI, PET, UTG, or UFG, the resin is preferably a high-viscosity resin (e.g., viscosity between 10 cps and 400 cps) with low pressure sensitivity (generally less than 6000g), and the micropatterned layer 3 is preferably fabricated using slot coating or exposure and development processes.

[0048] Furthermore, existing methods involve adding a separate adhesive layer to the micropatterned layer 3 to fix the vibrating layer 1 and the non-vibrating layer 2. However, because the adhesive layer is thin, its adhesion decreases under high temperature and humidity, causing the vibrating layer 1 to separate from the non-vibrating layer 2, resulting in poor reliability. Therefore, compared to this existing fixing method, the present invention achieves high-strength structural support, high shear strength, and high adhesion of the micropatterned layer 3 by integrally processing a resin layer internally doped with alumina nanoparticles, thereby improving the overall operational reliability of the product. Additionally, the present invention preferably uses 3D printing to process the micropatterned layer 3. Compared to exposure and development processes, 3D printing eliminates the need for multi-step exposure and development processes (such as chemical copper plating and etching), significantly shortening the development cycle and offering advantages such as lower cost, wider applicability, and higher precision and flexibility.

[0049] Furthermore, when the aforementioned vibrating substrate layer 12 and non-vibrating substrate layer 21 are SUS steel plates or carbon fiber plates, if it is an SUS steel plate, since SUS steel plates are conductive, no treatment is required. If it is a carbon fiber plate, since most carbon fiber plates are composite materials, most are non-conductive, and even those that are conductive have insufficient conductivity. Therefore, when the aforementioned vibrating substrate layer 12 and non-vibrating substrate layer 21 are carbon fiber plates, a composite metal layer (such as graphene-doped carbon nanotubes, not shown in the figure) is also provided on the surface of the vibrating substrate layer 12 and non-vibrating substrate layer 21. In practice, the composite metal layer can be formed by 3D printing on the surface of the vibrating substrate layer 12 and non-vibrating substrate layer 21, and its thickness is preferably less than 3 μm. The lower the sheet resistance, the lower the load power of the sound-generating screen will be, preferably not higher than 10 ohms. When the vibrating substrate layer 12 and the non-vibrating substrate layer 21 are the aforementioned CPI layer, PET layer, UTG or UFG, a transparent conductive layer (not shown) is also disposed on the surface of the vibrating substrate layer 12 and the non-vibrating substrate layer 21. In practice, the transparent conductive layer is an indium tin oxide layer, a graphene layer, a silver nanowire layer or a metal mesh, the thickness of the transparent conductive layer is less than 3 μm, and its sheet resistance is not higher than 10 ohms.

[0050] Furthermore, in traditional directional sound-emitting screens, the non-vibrating layer 2 is completely sealed after being bonded to the frame of the vibrating layer 1, i.e., it adopts a sealed air design. In high temperature and humidity or high and low pressure environments, the pressure difference between the inside and outside cannot be balanced, which can easily lead to deformation of the vibrating layer 1 and detachment of the adhesive layer of the micro-pattern layer 3, causing changes in the frequency capacitance of the finished product and reducing reliability. Preferably, the present invention provides a breathable structure 8 on the non-vibrating layer 2 located in the folded part 20, which communicates with the outside to ensure the balance of air pressure inside and outside the screen. In a specific embodiment, the breathable structure 8 specifically includes at least one vent 81 and at least one waterproof and breathable membrane 82, wherein the vent 81 penetrates the non-vibrating layer 2 (i.e., penetrates the non-vibrating substrate layer 21 and the insulating layer 22) to connect the air gap 4 inside the screen with the outside, and the waterproof and breathable membrane 82 covers the end of the vent 81 away from the vibrating layer 1. In practice, the pore diameter of the vent 81 is preferably 100um~500um. To ensure that the waterproof and breathable membrane 82 does not fall off the position for a long time, the length of the waterproof and breathable membrane 82 is preferably greater than the pore diameter of the vent 81, and preferably greater than 1mm in width.

[0051] The edge of the vibrating substrate layer 12 is bonded to the edge of the insulating layer 22 via a waterproof sealing structure 9. It should be noted that existing non-vibrating layer 2 is bonded to the frame of vibrating layer 1 using an inner-circle dispensing method. However, due to the increasing prevalence of narrow bezels (less than 1mm) in existing displays, dispensing leads to a certain yield loss and adhesive overflow. Furthermore, to ensure waterproofness, the adhesive needs to be thick and dense. However, since the height of the micro-patterned layer 3 is limited to below 35µm, excessive adhesive thickness can cause an edge difference between the screen edge and the screen interior. This edge difference results in uneven and reduced sound pressure in the directional sound-emitting screen, presenting a contradiction. Another disadvantage is that traditional frame adhesives require UV adhesives to ensure shear strength during the deformation of vibrating layer 1. For under-display OLED products, if the non-vibrating substrate layer 21 is made of SUS silicon steel or carbon fiber, the entire non-vibrating substrate layer 21 cannot transmit light during dispensing. If UV adhesive is still used, it will not cure. Therefore, preferably, the waterproof sealing structure 9 of this invention uses a hot-pressed waterproof adhesive strip 91. In practical implementation, the waterproof sealing joint 9 includes a hot-pressed waterproof strip 91 or a hot-pressed waterproof strip 91 and a side-sealing waterproof adhesive 92. The hot-pressed waterproof strip 91 has a pressing temperature below 70°C, a pressure below 3 kgf / cm², and a shear force reaching 8 MPa. The side-sealing waterproof adhesive 92 seals the outside of the hot-pressed waterproof strip 91 for secondary reinforcement.

[0052] In one embodiment, the total thickness of the vibration layer 1 is 300 μm, the height of the micropattern layer 3 is 5 μm to 7 μm, the height of the blind holes embedded in the vibration layer 1 is 10 μm, or the height of the through holes is 15 μm, and the spacing between two adjacent vibration units is 6 mm. In another alternative embodiment, the total thickness of the vibration layer 1 is 250 μm, the height of the micropattern layer 3 is 8 μm to 10 μm, the height of the blind holes embedded in the vibration layer 1 is 10 μm, or the height of the through holes is 15 μm, and the spacing between two adjacent vibration units is 6 mm. Furthermore, the spacing between two adjacent vibration units is preferably between 1 mm and 10 mm.

[0053] like Figure 5 As shown, the manufacturing process of a directional sound-emitting folding display screen disclosed in this invention mainly includes the following steps:

[0054] S1, Preparing the vibration layer 1 includes: providing a foldable screen 11 and a vibration substrate layer 12 integrally formed by 3D printing process, and attaching the lower end face of the foldable screen 11 away from the client to the vibration substrate layer 12 to form the vibration layer 1.

[0055] Specifically, the fabrication process of the foldable screen 11 includes:

[0056] S11, Prepare protective component 111, including:

[0057] S111, the end face of the folded substrate layer 1111 located in the folded part 20 and close to the client is thinned to form a first folded groove 5 that is recessed in the direction away from the client;

[0058] S112, a stress buffer layer 1112 is formed on the upper surface of the folded substrate layer 1111 near the client.

[0059] S113, an anti-scratch layer 1113 is formed on the upper surface of the stress buffer layer 1112 near the client.

[0060] Alternatively, in another alternative embodiment, the process of preparing the protective component 111 includes, in addition to S111-S113 described above, the following:

[0061] S114, an optical layer 1114 is formed on the upper surface of the anti-scratch layer 1113 near the client.

[0062] S12, fabricating screen assembly 112, including:

[0063] S121, the lower end of the OLED screen 1121 away from the client is bonded to the second OCA optical adhesive 1124;

[0064] S122, the polarizer layer 1123 with pressure-sensitive adhesive is bonded to the upper surface of the client and the first OCA optical adhesive 1122.

[0065] S123, the upper surface of the OLED screen 1121 is bonded to the lower surface of the polarizer layer 1123 with pressure-sensitive adhesive;

[0066] S13, the protective component 111 is bonded to the screen component 112 using the first OCA optical adhesive 1122 to form a foldable screen 11.

[0067] In addition, preferably, when the vibration substrate layer 12 is integrally formed by 3D printing, it also integrally forms a plurality of openings 121 and a second folding groove 6. The second folding groove 6 is a groove located on the upper end of the vibration substrate layer 12 near the client side of the folded part 20, which is recessed in the direction away from the client side. The upper end of the vibration substrate layer 12 near the client side is bonded to the folding screen 11 with a second OCA optical adhesive 1124 to form the vibration layer 1.

[0068] S2, preparing the non-vibration layer 2, including: forming an insulating layer 22 on the upper surface of the non-vibration substrate layer 21 near the client, and forming a micro-pattern layer 3 on the upper surface of the insulating layer 22 near the client. The micro-pattern layer 3 is formed by integrally processing a resin layer doped with alumina nanoparticles using 3D printing or exposure and development process, and the micro-pattern layer 3 consists of multiple insulating bumps.

[0069] Specifically, if the non-vibrating substrate layer 21 is the aforementioned CPI layer, PET layer, UTG, or UFG, a transparent conductive layer is printed on its upper surface near the vibrating layer 1. If it is a PET layer, the curing temperature is below 150°C; if it is a high-temperature resistant material such as CPI, UTG, or UFG, the curing temperature can be increased to above 250°C. If it is a SUS steel plate or carbon fiber plate, the non-vibrating substrate layer 21 is preferably integrally formed by 3D printing, slot coating, or exposure and development processes, with 3D printing being the most preferred. If it is a carbon fiber plate, a composite metal layer is printed on the upper surface of the non-vibrating substrate layer 21 near the vibrating layer 1. Furthermore, a third folding groove 7 is formed on the end face of the non-vibrating layer 21 located at the folded portion 20 and near the client, recessed in the direction away from the client. This third folding groove 7 can also be integrally formed during the printing of the non-vibrating substrate layer 21.

[0070] The insulating layer 22 is disposed on the upper surface of the non-vibrating substrate layer 21 near the vibrating layer 1. During processing, it can be formed on the non-vibrating substrate layer 21 by printing, screen printing or coating.

[0071] If the non-vibrating substrate layer 21 is made of opaque SUS steel plate or carbon fiber plate, the micro-pattern layer 3 is preferably processed by 3D printing followed by photopolymerization; if the non-vibrating substrate layer 21 is made of transparent CPI, PET, UTG or UFG, the micro-pattern layer 3 is preferably processed by slot coating or exposure and development process.

[0072] In addition, preferably, a vent hole 81 is formed through the non-vibration layer 2 located in the folded portion 20. During processing, the vent hole 81 can be formed by forming through holes when the non-vibration substrate layer 21 and the insulating layer 22 are respectively processed and formed. In this way, a through vent hole 81 is formed after the non-vibration substrate layer 21 and the insulating layer 22 are stacked. Alternatively, the vent hole 81 can be integrally formed on the non-vibration layer 2 after the non-vibration layer 2 is formed. The present invention does not limit this.

[0073] Finally, hot-pressed waterproof adhesive strips 91 are applied to the edge of the insulating layer 22 (located in the non-AA area, which refers to the non-effective display area), and the flexible circuit board 30 is bonded to the non-vibration layer 2.

[0074] S3, the vibrating layer 1 and the non-vibrating layer 2 are aligned and their frames are attached, and an air gap 4 is formed between the two through the micro-patterned layer 3 after attachment.

[0075] Specifically, the vibrating layer 1 and the non-vibrating layer 2 are aligned and bonded using a bonding device. Under pressure below 3 kgf / cm² and a temperature below 70°C, the edges of the vibrating layer 1 and the non-vibrating layer 2 are bonded together using a hot-pressed waterproof adhesive strip 91, and the insulating protrusions of the micro-patterned layer 3 are embedded and fixed to the openings 121 of the vibrating substrate layer 12. A second layer of side-sealing waterproof adhesive 92 can be applied to the outside of the hot-pressed waterproof adhesive strip 91 for secondary reinforcement. Finally, a waterproof and breathable membrane 82 is bonded to the end of the vent 81 furthest from the vibrating layer.

[0076] In addition, the design of the structure, materials and processing technology of each layer can be referred to the description in the above description of the directional sound folding display screen, and will not be repeated here.

[0077] The advantages of this invention are as follows: 1. This invention provides a novel directional sound-emitting screen integrated under an OLED foldable screen, forming a new type of directional sound-emitting foldable display screen combining a directional sound-emitting screen and an OLED foldable screen. Through improvements in the materials, processing technology, and structural design of the vibration substrate layer, and innovative design of the materials and processing technology of the micro-pattern layer, the overall operational reliability of the product is improved while achieving complete foldability of the directional sound-emitting foldable display screen. Furthermore, the innovative use of 3D printing technology significantly shortens the development cycle and offers advantages such as lower cost, wider applicability, and higher precision and flexibility. 2. This invention innovatively adds a scratch-resistant layer to the protective components of the original OLED foldable screen, significantly improving the scratch and wear resistance of the final product, thereby enhancing its operational reliability. 3. This invention cleverly adds a breathable structure to the folded portion of the non-vibration layer to ensure air pressure balance inside and outside the screen, avoiding existing problems such as easy deformation of the vibration layer, detachment of the adhesive layer of the micro-pattern layer, resulting in changes in the frequency capacitance of the finished product and reduced reliability. 4. This invention replaces the existing inner ring adhesive method with a hot-pressed waterproof adhesive strip for frame fixing. It is suitable for narrow bezel areas of existing displays with a thickness of less than 1mm. It will not cause adhesive overflow and can also ensure the bonding stability between the vibrating layer and the non-vibrating layer, thereby ensuring the reliability of the product.

[0078] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the 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 invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A directional sound-emitting folding display screen, characterized in that, include: The display screen comprises a vibrating layer, a non-vibrating layer, and a micro-patterned layer located between the vibrating layer and the non-vibrating layer. The edges of the vibrating layer and the non-vibrating layer are attached together, and an air gap is formed between them through the micro-patterned layer. The vibrating layer vibrates and emits sound in a direction closer to or farther from the non-vibrating layer under the action of an externally applied ultrasonic signal. The directional sound-emitting folding display screen includes a plurality of functional parts distributed along a first direction and at least one folding part. Each pair of adjacent functional parts is connected by a folding part. The functional parts are folded away from or closer to the client so that the adjacent functional parts are stacked on top of each other in a second direction. The vibration layer includes a foldable screen and a vibration substrate layer. The vibration substrate layer is integrally formed using 3D printing technology and is disposed on the lower end surface of the foldable screen away from the client. The non-vibration layer includes a non-vibration substrate layer, an insulating layer, and the micro-pattern layer. The insulating layer is disposed on the upper end surface of the non-vibration substrate layer near the vibration layer. The micro-pattern layer consists of multiple insulating bumps formed on the upper end surface of the insulating layer near the vibration layer, and it is integrally formed by using 3D printing, slot coating, or exposure and development technology to form a resin layer doped with alumina nanoparticles. The doping concentration of the alumina nanoparticles ranges from 1% to 15%, and each insulating bump contains at least one alumina nanoparticle.

2. The directional sound-emitting folding display screen as described in claim 1, characterized in that, The vibration substrate layer is a SUS steel plate or a carbon fiber plate.

3. A directional sound-emitting folding display screen as described in claim 1 or 2, characterized in that, The diameter of the alumina nanoparticles is 16µm~20µm or 1µm~10µm.

4. A directional sound-emitting folding display screen as described in claim 1, characterized in that, A breathable structure communicating with the outside is provided on the non-vibration layer located in the fold. The breathable structure includes at least one vent that penetrates the non-vibration layer to connect the air gap and the outside, and a waterproof and breathable membrane. The waterproof and breathable membrane covers the end of the vent that is away from the vibration layer.

5. A directional sound-emitting folding display screen as described in claim 4, characterized in that, The pore size of the vent is 100um~500um.

6. A directional sound-emitting folding display screen as described in claim 1, characterized in that, The edge of the vibrating substrate layer is bonded to the edge of the insulating layer by a waterproof sealing structure, which includes a hot-pressed waterproof strip or a hot-pressed waterproof strip and a side-sealing waterproof adhesive; the side-sealing waterproof adhesive is sealed to the outside of the hot-pressed waterproof strip.

7. A directional sound-emitting folding display screen as described in claim 1, characterized in that, The foldable screen includes a screen assembly and a protective assembly. The screen assembly is located between the protective assembly and the vibration substrate layer. The screen assembly includes an OLED screen or the screen assembly includes, from top to bottom, a first OCA optical adhesive, a polarizer layer with pressure-sensitive adhesive, an OLED screen, and a second OCA optical adhesive. The upper surface of the screen assembly is bonded to the protective assembly through the first OCA optical adhesive, and the lower surface is bonded to the vibration substrate layer through the second OCA optical adhesive.

8. A directional sound-emitting folding display screen as described in claim 7, characterized in that, The protective component includes a scratch-resistant layer, a stress-reducing layer, and a folded substrate layer stacked sequentially from top to bottom, or the protective component includes an optical layer, a scratch-resistant layer, a stress-reducing layer, and a folded substrate layer stacked sequentially from top to bottom.

9. A directional sound-emitting folding display screen as described in claim 8, characterized in that, The scratch-resistant layer is an alumina nanoparticle scratch-resistant layer; and / or, the thickness of the scratch-resistant layer is less than 5 μm.

10. A directional sound-emitting folding display screen as described in claim 1, characterized in that, Multiple openings are integrally formed on the vibrating substrate layer by 3D printing. The openings are either through holes or blind holes that are recessed from the lower end of the vibrating substrate layer toward its upper end. The openings correspond to the insulating protrusions of the micro-patterned layer. After the edges of the vibrating layer and the non-vibrating layer are attached, the insulating protrusions of the micro-patterned layer are embedded and fixed into the openings, forming the air gap between them and the top of the openings.

11. A directional sound-emitting folding display screen as described in claim 10, characterized in that, The openings are arranged in a honeycomb pattern.

12. A directional sound-emitting folding display screen as described in claim 2, characterized in that, The non-vibration substrate layer is any one of SUS steel plate, carbon fiber plate, CPI layer, PET layer, UTG, and UFG.

13. A directional sound-emitting folding display screen as described in claim 12, characterized in that, When the vibrating substrate layer and the non-vibrating substrate layer are carbon fiber plates, a composite metal layer is further disposed on the surface of the vibrating substrate layer and the non-vibrating substrate layer. The thickness of the composite metal layer is less than 3 μm, and its sheet resistance is not higher than 10 ohms.

14. A directional sound-emitting folding display screen as described in claim 8, characterized in that, The end faces of the folded substrate layer, the vibrating substrate layer, and the non-vibrating substrate layer located at the fold and close to the client are thinned to form a folded groove that is recessed in the direction away from the client.

15. A directional sound-emitting folding display screen as described in claim 14, characterized in that, The opening size of the folded groove is 5um to 8um.

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