Active ear pressure sensor and its fabrication method

Abstract

This invention relates to the field of headphone technology, specifically disclosing an active ear pressure sensor and its fabrication method. The sensor includes a flexible earplug with an ear cap and an ear post connected to each other. The ear cap is folded over the ear post to form a folded portion covering the ear post. Between the folded portion and the ear post is a flexible pressure-sensitive layer for converting the pressure on the folded portion into a resistance signal, and a conductive electrode layer for outputting a signal based on the resistance signal. The folded portion has a pressure-receiving surface for contacting the ear canal, and the end face of the folded portion facing away from the pressure-receiving surface forms a pressure-applying surface. The pressure-applying surface is used to change the relative distance and contact area between the flexible pressure-sensitive layer and the conductive electrode layer. The sensor of this invention has a simple structure, high adaptability to the shape and structure of headphones and ear canals, and can more accurately detect the pressure exerted by the headphones on the inner wall of the ear canal during actual use.

Description

Technical Field

[0001] This invention relates to the field of headphone technology, and in particular to an active ear pressure sensor and its fabrication method. Background Technology

[0002] Headphones are a common wearable product, and since they are often worn for extended periods, improving their comfort is particularly important. The pressure exerted by headphones on the ear is closely related to wearing comfort. By testing and providing feedback on the pressure exerted by headphones on the ear, this can be applied to improve wearing comfort. However, most existing ear pressure sensors are located outside the ear canal and can only measure the pressure exerted by the headphones on the outside of the ear canal. For in-ear headphones, which need to be inserted into the ear canal after being worn, the pressure exerted by the headphones on the inner wall of the ear canal is the key factor affecting wearing comfort. Therefore, existing ear pressure sensors are not suitable for in-ear headphones. In addition, existing ear pressure sensors have poor compatibility with the shape and structure of headphones and ears. Directly embedding them in the ear canal makes it difficult to conform to the curved and irregular shape of the headphones and ear canal, thus making it difficult to accurately detect the pressure exerted by headphones on the inner wall of the ear canal during actual use. Summary of the Invention

[0003] The purpose of this invention is to provide an active ear pressure sensor and its preparation method in view of the existing technology. The active ear pressure sensor of this invention has a simple structure and high adaptability to the shape and structure of the earphone and ear canal, and can more accurately detect the pressure of the earphone on the inner wall of the ear canal during actual use.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] First, as one of the objectives of this invention, this invention provides an active ear pressure sensor, including a flexible earplug, wherein the flexible earplug is provided with an ear cap and an ear post that are connected to each other;

[0006] The ear cap is folded up along the direction close to the ear post to form a folded portion covering the ear post. A flexible pressure-sensitive layer for converting the pressure on the folded portion into a resistance signal and a conductive electrode layer for outputting a signal based on the resistance signal are provided between the folded portion and the ear post.

[0007] The folded portion is provided with a pressure-receiving surface for contacting the ear canal, and the end face of the folded portion facing away from the pressure-receiving surface forms a pressure-applying surface. The pressure-applying surface is used to change the relative distance and contact area between the flexible pressure-sensitive layer and the conductive electrode layer.

[0008] In some preferred embodiments, the flexible pressure-sensitive layer is connected to the pressure-applying surface, and the conductive electrode layer is circumferentially disposed on the ear column;

[0009] Alternatively, the flexible pressure-sensitive layer is connected to the ear column, and the conductive electrode layer is circumferentially disposed on the pressure-applying surface.

[0010] In some preferred embodiments, the conductive electrode layer is circumferentially disposed on the ear post, and the flexible pressure-sensitive layer is sleeved outside the conductive electrode layer.

[0011] In some preferred embodiments, the conductive electrode layer includes a contact conduction segment for contacting the flexible pressure-sensitive layer and a lead segment for electrical connection with the earphone body.

[0012] In some preferred embodiments, the conductive electrode layer includes a contact conductive section, a lead wire section, and a connecting section. The contact conductive section is used to contact the flexible pressure-sensitive layer, the lead wire section is used to electrically connect to the earphone body, and the connecting section is used to connect the contact conductive section and the lead wire section. The contact conductive section is disposed on the pressure-applying surface, the lead wire section is disposed on the earpiece, and the connecting section is disposed at the connection between the folded portion and the earpiece.

[0013] The flexible pressure-sensitive layer covers the lead segment and the connecting segment;

[0014] Alternatively, the lead segment and connecting segment are covered with an insulating layer, and the flexible pressure-sensitive layer is disposed outside the insulating layer.

[0015] In some preferred embodiments, the conductive electrode layer is an interdigitated electrode.

[0016] In some preferred embodiments, the flexible pressure-sensitive layer is a pressure-sensitive ink layer or a conductive substrate layer. The conductive substrate layer includes a substrate layer with conductive particles distributed thereon. The substrate layer is any one or more combinations of a sponge layer, a silicone layer, or a fabric layer.

[0017] Secondly, as another objective of this invention, this invention provides a method for preparing an active ear pressure sensor, comprising:

[0018] A flexible earplug is prepared, wherein the flexible earplug is provided with an ear cap and an ear post connected to each other, the ear cap is folded in a direction close to the ear post to form a folded part covering the ear post, the folded part is provided with a pressure-receiving surface for contacting the ear canal, and the end face of the folded part facing away from the pressure-receiving surface forms a pressure-applying surface;

[0019] Fold the folded part of the ear cap outwards and fix it on the mold support;

[0020] A conductive electrode layer is printed around the columella, and a flexible pressure-sensitive layer is printed or bonded to the pressure-applying surface.

[0021] Alternatively, a conductive electrode layer may be printed on the pressure-applying surface, and a flexible pressure-sensitive layer may be printed or bonded around the columella.

[0022] Alternatively, a conductive electrode layer can be printed around the stud, and a flexible pressure-sensitive layer can be sleeved on the outside of the conductive electrode layer.

[0023] In some preferred embodiments, the flexible pressure-sensitive layer is a pressure-sensitive sponge layer, and the preparation steps of the pressure-sensitive sponge layer include:

[0024] A conductive composite is obtained by mixing and stirring waterborne polyurethane, conductive particles, and a dispersant.

[0025] The sponge layer is impregnated in a conductive composite for one impregnation, then removed, cured, and then impregnated a second time to obtain a pressure-sensitive sponge layer.

[0026] Furthermore, as another objective of this invention, this invention provides a method for preparing an active ear pressure sensor, comprising:

[0027] A flexible earplug is prepared, wherein the flexible earplug is provided with an ear cap and an ear post connected to each other, the ear cap is folded in a direction close to the ear post to form a folded part covering the ear post, the folded part is provided with a pressure-receiving surface for contacting the ear canal, and the end face of the folded part facing away from the pressure-receiving surface forms a pressure-applying surface;

[0028] Fold the folded part of the ear cap outwards and fix it on the mold support;

[0029] A conductive electrode layer is printed on the pressure-applying surface and the earpiece. The conductive electrode layer includes a contact conductive section, a lead wire section, and a connecting section. The contact conductive section is used to contact the flexible pressure-sensitive layer. The lead wire section is used to electrically connect to the earphone body. The connecting section is used to connect the contact conductive section and the lead wire section. The contact conductive section is located on the pressure-applying surface. The lead wire section is located on the earpiece. The connecting section is located at the connection between the folded portion and the earpiece.

[0030] An insulating layer is printed, bonded, or sleeved on the stud, and a flexible pressure-sensitive layer is printed, bonded, or sleeved on the insulating layer, the insulating layer covering the lead segment and the connecting segment;

[0031] Alternatively, a flexible pressure-sensitive layer may be printed, bonded, or fitted onto the stud, the flexible pressure-sensitive layer covering the lead segment and connecting segment.

[0032] The beneficial effects of this invention are as follows:

[0033] This invention integrates a flexible pressure-sensitive layer and a conductive electrode layer between the folded portion and the earpiece of a flexible earplug. Applied to headphones, it functions as a conventional earplug while simultaneously providing feedback to the user on the pressure exerted on the ear canal wall. Since it doesn't alter the way conventional earplugs are worn, the detected pressure values ​​are closer to those in actual use. The flexible pressure-sensitive layer conforms to the shape of the flexible earplug; even when the earplug experiences only slight deformation under weak pressure, the layer deforms accordingly, facilitating the collection and detection of small pressure changes. During use, the flexible earplug... The earpiece is mounted on the earphone body via ear posts. When the earphone is worn, the pressure-bearing surface of the folded part contacts and is squeezed by the inner wall of the ear canal, causing deformation. This deformation is then transmitted through the pressure-bearing surface to the flexible pressure-sensitive layer and the conductive electrode layer. The relative distance and contact area between the flexible pressure-sensitive layer and the conductive electrode layer change, thereby converting the pressure on the folded part into a resistance signal and outputting this resistance signal. This allows for accurate measurement of the pressure exerted by the earphone on the inner wall of the ear canal during actual use. The product has a simple structure and high adaptability to the shape and structure of the earphone and ear canal, enabling more accurate detection of the pressure exerted by the earphone on the inner wall of the ear canal during actual use. Attached Figure Description

[0034] Figure 1 This is a perspective view of the active ear pressure sensor in Embodiment 1 of the present invention with the ear cap turned outwards.

[0035] Figure 2 This is a perspective view of the active ear pressure sensor in Embodiment 1 of the present invention with the ear cap turned outwards.

[0036] Figure 3 This is a flowchart of the preparation method of the active ear pressure sensor in Embodiment 1 of the present invention.

[0037] Figure 4 This is a schematic diagram of the structure of the active ear pressure sensor in Embodiment 2 of the present invention with the ear cap turned outward.

[0038] Figure 5 This is a schematic diagram of the structure of the active ear pressure sensor in Embodiment 2 of the present invention with the ear cap folded over.

[0039] Figure 6 This is a schematic diagram of the structure of the active ear pressure sensor in Embodiment 3 of the present invention with the ear cap turned outward.

[0040] Figure 7 This is a flowchart of the preparation method of the active ear pressure sensor in Embodiment 3 of the present invention.

[0041] Figure 8 This is a schematic diagram of the structure of the active ear pressure sensor in Embodiment 4 of the present invention with the ear cap turned outward.

[0042] Figure 9 This is a flowchart of the preparation method of the active ear pressure sensor in Embodiment 4 of the present invention.

[0043] Figure 10 This is a schematic diagram of the structure of the active ear pressure sensor in Embodiment 5 of the present invention with the ear cap turned outward.

[0044] Figure 11 This is a flowchart of the preparation method of the active ear pressure sensor in Embodiment 5 of the present invention.

[0045] Figure 12 This is a schematic diagram of the structure of the active ear pressure sensor in Embodiment 6 of the present invention with the ear cap turned outward.

[0046] Figure 13 This is a flowchart of the preparation method of the active ear pressure sensor in Embodiment 6 of the present invention. Detailed Implementation

[0047] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0048] Example 1

[0049] Please see Figure 1 , Figure 2 and Figure 5 As shown, the present invention discloses an active ear pressure sensor, including a flexible earplug, the flexible earplug having an ear cap 1 and an ear post 2 connected to each other;

[0050] The ear cap 1 is folded up along the direction close to the ear post 2 to form a folded part 3 covering the ear post 2. A flexible pressure-sensitive layer 4 for converting the pressure on the folded part 3 into a resistance signal and a conductive electrode layer 5 for outputting a signal based on the resistance signal are provided between the folded part 3 and the ear post 2. The output signal of the conductive electrode layer 5 is any one of a resistance signal, a voltage signal or a current signal.

[0051] The folded portion 3 is provided with a pressure-receiving surface for contacting the ear canal. The end face of the folded portion 3 facing away from the pressure-receiving surface forms a pressure-applying surface 31. The pressure-applying surface 31 is used to change the relative distance and contact area between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5.

[0052] In this embodiment, the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 are integrated between the folded portion 3 and the ear post 2 of the flexible earplug and applied to headphones. On the one hand, it can function as a regular earplug, and on the other hand, it can provide feedback to the user on the pressure of wearing headphones on the inner wall of the ear canal. Since it does not change the wearing method of conventional earplug headphones, the detected pressure value is closer to the pressure value in actual application. The flexible pressure-sensitive layer 4 can conform to the shape of the flexible earplug. Even when the flexible earplug is subjected to weak force and only undergoes slight deformation, the flexible pressure-sensitive layer 4 can deform with the pressure deformation of the flexible earplug, which is conducive to collecting and detecting small pressure changes. In use, the flexible earplug is installed on the headphone body through the ear post 2. After wearing the headphones, the flexible earplug extends into the ear canal, and the pressure-receiving surface of the folded portion 3 is in contact with the inner wall of the ear canal. The flexible pressure-sensitive layer 4 deforms upon contact with and pressure from the inner wall of the ear canal. This deformation is then applied to the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 via the pressure-applying surface 31. As the flexible pressure-sensitive layer 4 deforms and shifts, it is pressed against the conductive electrode layer 5, causing them to come into contact. The relative distance and contact area between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 change, thereby converting the pressure on the folded portion 3 into a resistance signal and outputting this resistance signal. The greater the pressure on the folded portion 3, the smaller the output resistance. Based on the output resistance signal, the pressure value can be calculated, thus accurately obtaining the pressure exerted by the earphone on the inner wall of the ear canal during actual use. The product has a simple structure and high adaptability to the shape and structure of the earphone and ear canal, enabling more accurate detection of the pressure exerted by the earphone on the inner wall of the ear canal during actual use.

[0053] For example, the flexible earplugs may be made of materials such as silicone, polyurethane (PU), sponge, fabric, polyvinyl chloride (PVC), ethylene-vinyl acetate copolymer (EVA), styrene (SBS), etc., but are not limited to these.

[0054] The conductive electrode layer 5 can be made of conductive silver paste, carbon paste, copper paste, gold paste, ITO, etc., but is not limited to these.

[0055] The flexible pressure-sensitive layer 4 is either a pressure-sensitive ink layer or a conductive substrate layer. The conductive substrate layer includes a substrate layer with conductive particles distributed thereon. The substrate layer can be any one or more combinations of a sponge layer, a silicone layer, or a fabric layer. The pressure-sensitive ink layer or the conductive substrate layer can be a commercially available product or a self-made product. The pressure-sensitive ink layer can be directly deposited on the surface of the pressure-applying surface 31 or the ear post 2 by printing. The conductive substrate layer can be fixed to the pressure-applying surface 31 or the ear post 2 by means of adhesion, sleeve, etc.

[0056] For example, the conductive particles may be made of carbon nanotubes, carbon black particles, graphene oxide, etc., but are not limited to these.

[0057] The conductive substrate layer can be prepared by depositing conductive particles on the surface of the substrate layer through spraying, printing or other means to distribute the conductive particles on the surface of the substrate layer, or by immersing the substrate layer in a liquid containing conductive particles to distribute the conductive particles inside and outside the substrate layer.

[0058] See Figures 1 to 2 As shown, the flexible pressure-sensitive layer 4 is connected to the pressure-applying surface 31, and the conductive electrode layer 5 is circumferentially disposed on the ear post 2. The shape of the flexible pressure-sensitive layer 4 is consistent with the shape of the pressure-applying surface 31. The flexible pressure-sensitive layer 4 can be fixed to the pressure-applying surface 31 by means of printing, bonding, or sleeve. The conductive electrode layer 5 can be fixed to the ear post 2 by means of 3D printing, inkjet printing, dot coating, or spraying. In this embodiment, the flexible pressure-sensitive layer 4 is a pressure-sensitive ink layer, which is directly printed on the surface of the pressure-applying surface 31, and the conductive electrode layer 5 is deposited around the ear post 2 by 3D printing.

[0059] In this embodiment, the flexible pressure-sensitive layer 4 is disposed on the pressure-applying surface 31, and the conductive electrode layer 5 is disposed on the ear column 2. When no pressure is applied, there is a gap between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5, and the two do not contact each other. When the inner wall of the ear canal applies pressure to the ear cap 1, the flexible pressure-sensitive layer 4 deforms and shifts, and the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 are squeezed together and come into contact with each other. The relative distance and contact area between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 change, and the output resistance also changes accordingly. The pressure on the folded part 3 is converted into a resistance signal and the resistance signal is output. Based on the output resistance signal, the pressure of the earphone on the inner wall of the ear canal in actual application can be accurately obtained.

[0060] In another scenario, when no pressure is applied, there is micro-contact between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5, and the flexible pressure-sensitive layer 4 is not subjected to pressure from the pressure surface 31.

[0061] When the inner wall of the ear canal applies pressure to the ear cap 1, the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 are squeezed together and come into contact with each other. The contact area between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 changes, the flexible pressure-sensitive layer 4 deforms, and the output resistance also changes accordingly. The pressure on the folded part 3 is converted into a resistance signal and the resistance signal is output. Based on the output resistance signal, the pressure of the earphone on the inner wall of the ear canal in actual application can be accurately obtained.

[0062] See Figure 1As shown, the conductive electrode layer 5 includes a contact conductive section 51 for contacting the flexible pressure-sensitive layer 4 and a lead wire section 53 for electrical connection with the earphone body. In this embodiment, multiple contact conductive sections 51 are evenly arranged around the ear post 2 or the pressure surface 31. Each contact conductive section 51 is arranged along the length direction of the ear post 2 or the pressure surface 31. The even arrangement of the contact conductive sections 51 around the ear post 2 or the pressure surface 31 can increase the contact area with the flexible pressure-sensitive layer 4 and enable the product to detect ear pressure in various directions of the inner wall of the ear canal. Each contact conductive section 51 is arranged along the length direction of the ear post 2 or the pressure surface 31 to conform to the profile of the ear post 2 or the pressure surface 31, improve the adaptability of the conductive electrode layer 5 to the shape and structure of the flexible earplug, and further improve the accuracy of detection.

[0063] Preferably, the conductive electrode layer 5 is an interdigitated electrode. The contact area between the interdigitated electrode and the flexible pressure-sensitive layer 4 is large, the force is uniform, and the output signal has good consistency, which further improves the accuracy of detection.

[0064] See Figure 3 As shown, this invention discloses a method for fabricating an active ear pressure sensor, comprising:

[0065] S10. Prepare a flexible earplug. The flexible earplug is provided with an ear cap 1 and an ear post 2 connected to each other. The ear cap 1 is folded in the direction close to the ear post 2 to form a folded part 3 covering the ear post 2. The folded part 3 is provided with a pressure-receiving surface for contacting the ear canal. The end face of the folded part 3 facing away from the pressure-receiving surface forms a pressure-applying surface 31.

[0066] S20. Fold the folded part 3 of the ear cap 1 outward and fix it on the mold support;

[0067] S30. A conductive electrode layer 5 is printed around the ear post 2. Exemplarily, the method for printing the conductive electrode layer 5 can be 3D printing, inkjet printing, dot coating, spraying, etc., but is not limited to these. In this embodiment, the conductive electrode layer 5 is printed by 3D printing. The conductive electrode layer 5 is a silver electrode. The specific steps are as follows:

[0068] Conductive silver paste was deposited on the surface of the earpiece 2 of the flexible earplug using 3D printing according to the designed electrode pattern, and then cured at 150°C to form a conductive electrode layer 5.

[0069] S40. A flexible pressure-sensitive layer 4 is printed on the pressure-applying surface 31. In this embodiment, the flexible pressure-sensitive layer 4 is a conductive ink layer, wherein the conductive ink is conductive silicone ink. The specific steps are as follows:

[0070] S41. The silica gel, carbon nanotubes and silane coupling agent of component A are mechanically stirred in a three-necked flask for 4 hours, and then mixed with the silica gel of component B and stirred evenly to obtain conductive silica gel ink. The sheet resistance of the flexible pressure-sensitive layer 4 formed later can be adjusted by adjusting the content ratio of carbon nanotubes.

[0071] S42. Conductive silicone ink is printed on the surface of the pressure surface 31 and cured at 50°C to form a flexible pressure-sensitive layer 4.

[0072] The order of steps S30 and S40 can be reversed or performed simultaneously.

[0073] After preparation, the ear cap 1 is reset, the lead segment 53 of the conductive electrode layer 5 is electrically connected to the headphone body, the flexible earplug is installed on the headphone body, and then the ear pressure test can be performed.

[0074] The product has a simple processing technology, low production cost, and is conducive to industrial production and wide application, enabling personalized customization.

[0075] Example 2

[0076] See Figure 4 and Figure 5 As shown, the difference between this embodiment and embodiment 1 is that the conductive electrode layer 5 is also connected to a connecting segment 52 for connecting each conductive electrode layer 5.

[0077] Example 3

[0078] See Figure 6 As shown, the difference between this embodiment and embodiment 2 is that the conductive electrode layer 5 is circumferentially disposed on the ear post 2, and the flexible pressure-sensitive layer 4 is sleeved on the outside of the conductive electrode layer 5.

[0079] Without applying pressure, the flexible pressure-sensitive layer 4 maintains micro-contact with the conductive electrode layer 5, and the flexible pressure-sensitive layer 4 is not subjected to pressure from the pressure surface 31.

[0080] When the inner wall of the ear canal applies pressure to the ear cap 1, the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 are squeezed together and come into contact with each other. The contact area between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 changes, the flexible pressure-sensitive layer 4 deforms, and the output resistance also changes accordingly. The pressure on the folded part 3 is converted into a resistance signal and the resistance signal is output. Based on the output resistance signal, the pressure of the earphone on the inner wall of the ear canal in actual application can be accurately obtained.

[0081] In this embodiment, since both the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 are located on the ear post 2, the manufacturing process is relatively simple, and the output resistance signal is more easily conducted after being squeezed, resulting in better accuracy.

[0082] In this embodiment, the flexible pressure-sensitive layer 4 is a conductive substrate layer, which includes a substrate layer, conductive particles distributed in the substrate layer, and the substrate layer is a polyurethane sponge layer.

[0083] See Figure 7 As shown, this invention discloses a method for fabricating an active ear pressure sensor, comprising:

[0084] S10. Prepare a flexible earplug. The flexible earplug is provided with an ear cap 1 and an ear post 2 connected to each other. The ear cap 1 is folded in the direction close to the ear post 2 to form a folded part 3 covering the ear post 2. The folded part 3 is provided with a pressure-receiving surface for contacting the ear canal. The end face of the folded part 3 facing away from the pressure-receiving surface forms a pressure-applying surface 31.

[0085] S20. Fold the folded part 3 of the ear cap 1 outward and fix it on the mold support;

[0086] S30. A conductive electrode layer 5 is printed around the columella 2. In this embodiment, the conductive electrode layer 5 is printed using 3D printing. The conductive electrode layer 5 is a silver electrode. The specific steps are as follows:

[0087] Conductive silver paste was deposited on the surface of the earpiece 2 of the flexible earplug using 3D printing according to the designed electrode pattern, and then cured at 150°C to form a conductive electrode layer 5.

[0088] S40. A flexible pressure-sensitive layer 4 is sleeved on the outside of the conductive electrode layer 5, wherein the flexible pressure-sensitive layer 4 is a pressure-sensitive sponge layer, and the preparation steps of the pressure-sensitive sponge layer include:

[0089] A conductive composite is obtained by mixing and stirring waterborne polyurethane, conductive particles, and a dispersant.

[0090] The sponge layer is impregnated in a conductive composite for one impregnation, then removed, cured, and then impregnated a second time to obtain a pressure-sensitive sponge layer.

[0091] The pressure-sensitive sponge layer has a simple processing technology, low manufacturing cost, and is conducive to the industrial production of the product.

[0092] Specifically, in this embodiment, the preparation steps of the pressure-sensitive sponge layer include:

[0093] A conductive composite was obtained by mixing waterborne polyurethane, carbon nanotubes, carbon black particles and dispersant in a certain mass ratio and mechanically stirring at room temperature for 4 hours.

[0094] The polyurethane foam layer is placed in the conductive composite and impregnated for 1 hour. Afterward, it is removed, excess material is removed, and it is cured at 80°C. A second impregnation is then performed for 1 hour to obtain the pressure-sensitive foam layer.

[0095] Example 4

[0096] See Figure 8 As shown, the difference between this embodiment and embodiment 2 is that the conductive electrode layer 5 includes a contact conductive section 51, a lead wire section 53, and a connecting section. The contact conductive section 51 is used to contact the flexible pressure-sensitive layer 4, the lead wire section 53 is used to electrically connect to the earphone body, and the connecting section is used to connect the contact conductive section and the lead wire section 53. The conductive electrode layer 5 is also connected to a connecting section 52 for connecting each conductive electrode layer 5. The contact conductive section 51 and the connecting section 52 are disposed on the pressure surface 31, the lead wire section 53 is disposed on the ear post 2, and the connecting section is disposed at the connection between the folded part 3 and the ear post 2. The lead wire section 53 and the connecting section are covered with an insulating layer 6. The insulating layer 6 can be insulating silicone, insulating ink layer, or insulating film material. The insulating film material can be PET film, PI film, TPU film, etc. By covering the lead wire section 53 and the connecting section with the insulating layer 6, the problem of short circuit caused by the ear post 2 and the conductive electrode layer 5 on the folded part 3 coming into contact with each other when the folded part 3 folds outward toward the ear post 2 can be avoided.

[0097] When no pressure is applied, there is a gap between the contact conductive section 51 of the flexible pressure-sensitive layer 4 and the conductive electrode layer 5, and the two do not contact each other. When the inner wall of the ear canal applies pressure to the ear cap 1, the contact conductive section 51 of the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 are squeezed towards each other and come into contact. The relative distance and contact area between the contact conductive section 51 of the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 change, and the output resistance also changes accordingly. The pressure on the folded part 3 is converted into a resistance signal and the resistance signal is output. Based on the output resistance signal, the pressure of the earphone on the inner wall of the ear canal in actual application can be accurately obtained.

[0098] In another scenario, when no pressure is applied, there is micro-contact between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5, and the flexible pressure-sensitive layer 4 is not subjected to pressure from the pressure surface 31.

[0099] When the inner wall of the ear canal applies pressure to the ear cap 1, the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 are squeezed together and come into contact with each other. The contact area between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 changes, the flexible pressure-sensitive layer 4 deforms, and the output resistance also changes accordingly. The pressure on the folded part 3 is converted into a resistance signal and the resistance signal is output. Based on the output resistance signal, the pressure of the earphone on the inner wall of the ear canal in actual application can be accurately obtained.

[0100] In this embodiment, the flexible pressure-sensitive layer 4 is a pressure-sensitive ink layer.

[0101] See Figure 9 As shown, this invention discloses a method for fabricating an active ear pressure sensor, comprising:

[0102] S10. Prepare a flexible earplug. The flexible earplug is provided with an ear cap 1 and an ear post 2 connected to each other. The ear cap 1 is folded in the direction close to the ear post 2 to form a folded part 3 covering the ear post 2. The folded part 3 is provided with a pressure-receiving surface for contacting the ear canal. The end face of the folded part 3 facing away from the pressure-receiving surface forms a pressure-applying surface 31.

[0103] S20. Fold the folded part 3 of the ear cap 1 outward and fix it on the mold support;

[0104] S30. A conductive electrode layer 5 is printed on the pressure-applying surface 31 and the earpiece 2. The conductive electrode layer 5 includes a contact conductive section 51, a lead wire section 53, and a connecting section. The contact conductive section 51 is used to contact the flexible pressure-sensitive layer 4, the lead wire section 53 is used to electrically connect to the earphone body, and the connecting section is used to connect the contact conductive section and the lead wire section 53. The conductive electrode layer 5 is also connected to a connecting section 52 for connecting each conductive electrode layer 5. The contact conductive section 51 and the connecting section 52 are disposed on the pressure-applying surface 31, the lead wire section 53 is disposed on the earpiece 2, and the connecting section is disposed at the connection between the folded part 3 and the earpiece 2. In this embodiment, the conductive electrode layer 5 is printed by 3D printing. The conductive electrode layer 5 is a silver electrode. The specific steps are as follows:

[0105] Conductive silver paste was deposited on the surface of the earpiece 2 of the flexible earplug using 3D printing according to the designed electrode pattern, and then cured at 150°C to form a conductive electrode layer 5.

[0106] S40. Print, adhere or attach an insulating layer 6 on the ear post 2. The insulating layer 6 covers the lead segment 53 and the connecting segment. In this embodiment, insulating ink is sprayed on the conductive electrode layer 5 on the ear post 2 to form an insulating ink layer.

[0107] S50. Print the flexible pressure-sensitive layer 4 on the insulating layer 6. The specific steps are as follows:

[0108] S51. The silica gel, carbon nanotubes and silane coupling agent of component A are mechanically stirred in a three-necked flask for 4 hours, and then mixed with the silica gel of component B and stirred evenly to obtain conductive silica gel ink.

[0109] S52. Conductive silicone ink is printed on the surface of insulating layer 6 and cured at 50°C to form flexible pressure-sensitive layer 4;

[0110] S53. The obtained flexible pressure-sensitive layer 4 is printed on the surface of the insulating layer 6, wherein the flexible pressure-sensitive layer 4 can be printed as a whole or in segments.

[0111] Example 5

[0112] See Figure 10As shown, the difference between this embodiment and embodiment 2 is that the conductive electrode layer 5 includes a contact conductive section 51, a lead wire section 53, and a connecting section. The contact conductive section 51 is used to contact the flexible pressure-sensitive layer 4, the lead wire section 53 is used to electrically connect to the earphone body, and the connecting section is used to connect the contact conductive section and the lead wire section 53. The conductive electrode layer 5 is also connected to a connecting section 52 for connecting each conductive electrode layer 5. The contact conductive section 51 and the connecting section 52 are provided on the pressure surface 31, the lead wire section 53 is provided on the ear post 2, and the connecting section is provided at the connection between the folded part 3 and the ear post 2. The flexible pressure-sensitive layer 4 covers the lead wire section 53 and the connecting section. By covering the lead wire section 53 and the connecting section with the flexible pressure-sensitive layer 4, the problem of short circuit caused by the ear post 2 and the conductive electrode layer 5 on the folded part 3 contacting each other when the folded part 3 folds outward toward the ear post 2 can be avoided. At the same time, it is not necessary to provide an insulating layer as in embodiment 4, which further simplifies the structure and production steps.

[0113] In this embodiment, the flexible pressure-sensitive layer 4 is a conductive substrate layer, which includes a substrate layer, conductive particles distributed in the substrate layer, and the substrate layer is a polyester fabric layer.

[0114] When no pressure is applied, there is a gap between the contact conductive section 51 of the flexible pressure-sensitive layer 4 and the conductive electrode layer 5, and the two do not contact each other. When the inner wall of the ear canal applies pressure to the ear cap 1, the contact conductive section 51 of the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 are squeezed towards each other and come into contact. The relative distance and contact area between the contact conductive section 51 of the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 change, and the output resistance also changes accordingly. The pressure on the folded part 3 is converted into a resistance signal and the resistance signal is output. Based on the output resistance signal, the pressure of the earphone on the inner wall of the ear canal in actual application can be accurately obtained.

[0115] In another scenario, when no pressure is applied, there is micro-contact between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5, and the flexible pressure-sensitive layer 4 is not subjected to pressure from the pressure surface 31.

[0116] When the inner wall of the ear canal applies pressure to the ear cap 1, the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 are squeezed together and come into contact with each other. The contact area between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 changes, the flexible pressure-sensitive layer 4 deforms, and the output resistance also changes accordingly. The pressure on the folded part 3 is converted into a resistance signal and the resistance signal is output. Based on the output resistance signal, the pressure of the earphone on the inner wall of the ear canal in actual application can be accurately obtained.

[0117] See Figure 11 As shown, this invention discloses a method for fabricating an active ear pressure sensor, comprising:

[0118] S10. Prepare a flexible earplug. The flexible earplug is provided with an ear cap 1 and an ear post 2 connected to each other. The ear cap 1 is folded in the direction close to the ear post 2 to form a folded part 3 covering the ear post 2. The folded part 3 is provided with a pressure-receiving surface for contacting the ear canal. The end face of the folded part 3 facing away from the pressure-receiving surface forms a pressure-applying surface 31.

[0119] S20. Fold the folded part 3 of the ear cap 1 outward and fix it on the mold support;

[0120] S30. A conductive electrode layer 5 is printed on the pressure-applying surface 31 and the earpiece 2. The conductive electrode layer 5 includes a contact conductive section 51, a lead wire section 53, and a connecting section. The contact conductive section 51 is used to contact the flexible pressure-sensitive layer 4, the lead wire section 53 is used to electrically connect to the earphone body, and the connecting section is used to connect the contact conductive section and the lead wire section 53. The conductive electrode layer 5 is also connected to a connecting section 52 for connecting each conductive electrode layer 5. The contact conductive section 51 and the connecting section 52 are disposed on the pressure-applying surface 31, the lead wire section 53 is disposed on the earpiece 2, and the connecting section is disposed at the connection between the folded part 3 and the earpiece 2. In this embodiment, the conductive electrode layer 5 is printed by 3D printing. The conductive electrode layer 5 is a silver electrode. The specific steps are as follows:

[0121] Conductive silver paste was deposited on the surface of the earpiece 2 of the flexible earplug using 3D printing according to the designed electrode pattern, and then cured at 150°C to form a conductive electrode layer 5.

[0122] S40. Attach the flexible pressure-sensitive layer 4 to the ear post. The flexible pressure-sensitive layer 4 covers the lead segment 53 and the connecting segment. The specific steps are as follows:

[0123] S41. Preparation of flexible pressure-sensitive layer 4:

[0124] 1) Waterborne polyurethane, carbon nanotubes, carbon black particles, dispersant, defoamer and film-forming agent are mixed in a certain mass ratio, mechanically stirred at room temperature for 2 hours, and then ground four times with a three-roll mill to obtain a conductive composite.

[0125] 2) Preheat the polyester fabric layer at 100℃, then remove and iron it flat. Print the conductive composite onto the fabric substrate surface using screen printing, and cure it at 80℃ to obtain the flexible pressure-sensitive layer 4;

[0126] S42. Attach the flexible pressure-sensitive layer 4 to the ear post 2 using an adhesive.

[0127] Example 6

[0128] See Figure 12As shown, the difference between this embodiment and embodiment 2 is that the flexible pressure-sensitive layer 4 is connected to the ear post 2, and the conductive electrode layer 5 is circumferentially disposed on the pressure application surface 31. The flexible pressure-sensitive layer 4 can be fixed to the ear post 2 by means of printing, bonding, or sleeve, and the conductive electrode layer 5 can be fixed to the pressure application surface 31 by means of 3D printing, inkjet printing, dot coating, or spraying. In this embodiment, the flexible pressure-sensitive layer 4 is a pressure-sensitive ink layer, which is directly printed on the surface of the ear post 2, and the conductive electrode layer 5 is deposited on the pressure application surface 31 by 3D printing.

[0129] In this embodiment, the flexible pressure-sensitive layer 4 is disposed on the earpiece 2, and the conductive electrode layer 5 is disposed on the pressure-applying surface 31. When no pressure is applied, there is a gap between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5, and the two do not contact each other. When the inner wall of the ear canal applies pressure to the ear cap 1, the flexible pressure-sensitive layer 4 deforms and shifts, and the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 are squeezed together and come into contact with each other. The relative distance and contact area between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 change, and the output resistance also changes accordingly. The pressure on the folded part 3 is converted into a resistance signal and the resistance signal is output. Based on the output resistance signal, the pressure of the earphone on the inner wall of the ear canal in actual application can be accurately obtained.

[0130] In another scenario, when no pressure is applied, there is micro-contact between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5, and the flexible pressure-sensitive layer 4 is not subjected to pressure from the pressure surface 31.

[0131] When the inner wall of the ear canal applies pressure to the ear cap 1, the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 are squeezed together and come into contact with each other. The contact area between the flexible pressure-sensitive layer 4 and the conductive electrode layer 5 changes, the flexible pressure-sensitive layer 4 deforms, and the output resistance also changes accordingly. The pressure on the folded part 3 is converted into a resistance signal and the resistance signal is output. Based on the output resistance signal, the pressure of the earphone on the inner wall of the ear canal in actual application can be accurately obtained.

[0132] See Figure 13 As shown, this invention discloses a method for fabricating an active ear pressure sensor, comprising:

[0133] S10. Prepare a flexible earplug. The flexible earplug is provided with an ear cap 1 and an ear post 2 connected to each other. The ear cap 1 is folded in the direction close to the ear post 2 to form a folded part 3 covering the ear post 2. The folded part 3 is provided with a pressure-receiving surface for contacting the ear canal. The end face of the folded part 3 facing away from the pressure-receiving surface forms a pressure-applying surface 31.

[0134] S20. Fold the folded part 3 of the ear cap 1 outward and fix it on the mold support;

[0135] S30. A conductive electrode layer 5 is printed on the pressure surface 31. For example, the method of printing the conductive electrode layer 5 can be 3D printing, inkjet printing, dot coating, spraying, etc., but is not limited to these. In this embodiment, the conductive electrode layer 5 is printed by 3D printing. The conductive electrode layer 5 is a silver electrode. The specific steps are as follows:

[0136] Conductive silver paste was deposited on the surface of the earpiece 2 of the flexible earplug using 3D printing according to the designed electrode pattern, and then cured at 150°C to form a conductive electrode layer 5.

[0137] S40. A flexible pressure-sensitive layer 4 is printed around the ear post 2. In this embodiment, the flexible pressure-sensitive layer 4 is a conductive ink layer, wherein the conductive ink is conductive silicone ink. The specific steps are as follows:

[0138] S41. The silica gel, carbon nanotubes and silane coupling agent of component A are mechanically stirred in a three-necked flask for 4 hours, and then mixed with the silica gel of component B and stirred evenly to obtain conductive silica gel ink. The sheet resistance of the flexible pressure-sensitive layer 4 formed later can be adjusted by adjusting the content ratio of carbon nanotubes.

[0139] S42. Conductive silicone ink is printed on the surface of the ear post 2 and cured at 50°C to form a flexible pressure-sensitive layer 4.

[0140] The order of steps S30 and S40 can be reversed or performed simultaneously.

[0141] After preparation, the ear cap 1 is reset, the lead segment 53 of the conductive electrode layer 5 is electrically connected to the headphone body, the flexible earplug is installed on the headphone body, and then the ear pressure test can be performed.

[0142] Of course, the above illustrations are only preferred embodiments of the present invention and are not intended to limit the scope of application of the present invention. Therefore, any equivalent changes made to the principle of the present invention should be included within the protection scope of the present invention.

Claims

1. An active ear pressure sensor, characterized in that, A device for detecting the pressure of headphones on the inner wall of the ear canal during use includes a flexible earplug, wherein the flexible earplug is provided with an ear cap and an ear post that are connected to each other; The ear cap is folded up along the direction close to the ear post to form a folded portion covering the ear post. A flexible pressure-sensitive layer for converting the pressure on the folded portion into a resistance signal and a conductive electrode layer for outputting a signal based on the resistance signal are provided between the folded portion and the ear post. The folded portion is provided with a pressure-receiving surface for contacting the ear canal, and the end face of the folded portion facing away from the pressure-receiving surface forms a pressure-applying surface. The pressure-applying surface is used to change the relative distance and contact area between the flexible pressure-sensitive layer and the conductive electrode layer. The sensor obtains the pressure on the inner wall of the ear canal based on the change in the relative distance and contact area between the flexible pressure-sensitive layer and the conductive electrode layer.

2. The active ear pressure sensor according to claim 1, characterized in that, The flexible pressure-sensitive layer is connected to the pressure-applying surface, and the conductive electrode layer is circumferentially disposed on the ear post; Alternatively, the flexible pressure-sensitive layer is connected to the ear column, and the conductive electrode layer is circumferentially disposed on the pressure-applying surface.

3. The active ear pressure sensor according to claim 1, characterized in that, The conductive electrode layer is circumferentially disposed on the ear post, and the flexible pressure-sensitive layer is sleeved outside the conductive electrode layer.

4. The active ear pressure sensor according to claim 2 or 3, characterized in that, The conductive electrode layer includes a contact conduction section for contacting the flexible pressure-sensitive layer and a lead section for electrical connection with the earphone body.

5. The active ear pressure sensor according to claim 1, characterized in that, The conductive electrode layer includes a contact conductive section, a lead wire section, and a connecting section. The contact conductive section is used to contact the flexible pressure-sensitive layer, the lead wire section is used to electrically connect to the earphone body, and the connecting section is used to connect the contact conductive section and the lead wire section. The contact conductive section is disposed on the pressure-applying surface, the lead wire section is disposed on the earpiece, and the connecting section is disposed at the connection between the folded portion and the earpiece. The flexible pressure-sensitive layer covers the lead segment and the connecting segment; Alternatively, the lead segment and connecting segment are covered with an insulating layer, and the flexible pressure-sensitive layer is disposed outside the insulating layer.

6. The active ear pressure sensor according to any one of claims 1 to 5, characterized in that, The conductive electrode layer is an interdigitated electrode.

7. The active ear pressure sensor according to any one of claims 1 to 5, characterized in that, The flexible pressure-sensitive layer is a pressure-sensitive ink layer or a conductive substrate layer. The conductive substrate layer includes a substrate layer with conductive particles distributed thereon. The substrate layer is any one or more combinations of a sponge layer, a silicone layer, or a fabric layer.

8. A method for preparing an active ear pressure sensor according to any one of claims 1 to 7, characterized in that, include: A flexible earplug is prepared, wherein the flexible earplug is provided with an ear cap and an ear post connected to each other, the ear cap is folded in a direction close to the ear post to form a folded part covering the ear post, the folded part is provided with a pressure-receiving surface for contacting the ear canal, and the end face of the folded part facing away from the pressure-receiving surface forms a pressure-applying surface; Fold the folded part of the ear cap outwards and fix it on the mold support; A conductive electrode layer is printed around the columella, and a flexible pressure-sensitive layer is printed or bonded to the pressure-applying surface. Alternatively, a conductive electrode layer may be printed on the pressure-applying surface, and a flexible pressure-sensitive layer may be printed or bonded around the columella. Alternatively, a conductive electrode layer can be printed around the stud, and a flexible pressure-sensitive layer can be sleeved on the outside of the conductive electrode layer.

9. The preparation method according to claim 8, characterized in that, The flexible pressure-sensitive layer is a pressure-sensitive sponge layer, and the preparation steps of the pressure-sensitive sponge layer include: A conductive composite is obtained by mixing and stirring waterborne polyurethane, conductive particles, and a dispersant. The sponge layer is impregnated in a conductive composite for one impregnation, then removed, cured, and then impregnated a second time to obtain a pressure-sensitive sponge layer.

10. A method for preparing an active ear pressure sensor according to any one of claims 1 to 7, characterized in that, include: A flexible earplug is prepared, wherein the flexible earplug is provided with an ear cap and an ear post connected to each other, the ear cap is folded in a direction close to the ear post to form a folded part covering the ear post, the folded part is provided with a pressure-receiving surface for contacting the ear canal, and the end face of the folded part facing away from the pressure-receiving surface forms a pressure-applying surface; Fold the folded part of the ear cap outwards and fix it on the mold support; A conductive electrode layer is printed on the pressure-applying surface and the earpiece. The conductive electrode layer includes a contact conductive section, a lead wire section, and a connecting section. The contact conductive section is used to contact the flexible pressure-sensitive layer. The lead wire section is used to electrically connect to the earphone body. The connecting section is used to connect the contact conductive section and the lead wire section. The contact conductive section is located on the pressure-applying surface. The lead wire section is located on the earpiece. The connecting section is located at the connection between the folded portion and the earpiece. An insulating layer is printed, bonded, or sleeved on the stud, and a flexible pressure-sensitive layer is printed, bonded, or sleeved on the insulating layer, the insulating layer covering the lead segment and the connecting segment; Alternatively, a flexible pressure-sensitive layer may be printed, bonded, or fitted onto the stud, the flexible pressure-sensitive layer covering the lead segment and connecting segment.

Images