Bluetooth headset

Abstract

The embodiment of the present application provides a Bluetooth headset, which relates to the field of communication equipment and can effectively utilize the internal space of the Bluetooth headset and reduce the impact of product miniaturization on antenna performance. The Bluetooth headset includes an earplug portion and an ear handle portion; the ear handle portion includes a corner portion connected to the earplug portion and an ear handle rod connected to the corner portion, and a battery is provided inside the ear handle rod; the Bluetooth headset includes a flexible circuit board, the flexible circuit board includes a feeding portion and a first extension portion connected to the feeding portion; the feeding portion is provided at the corner portion, and the first extension portion extends to the ear handle rod; the feeding portion is provided with a feeding electrode, a main antenna is provided on a first side of the first extension portion, and at least one touch sensor is provided on a second side of the first extension portion; wherein the first side of the first extension portion faces the battery, the second side of the first extension portion faces the inner wall of the ear handle rod, and the feeding electrode is coupled to the main antenna.

Description

Technical Field

[0001] The present application relates to the technical field of communication equipment, and in particular to a Bluetooth headset. Background Art

[0002] Currently, Bluetooth headsets are popular among users due to their convenience and compact size, and their use is becoming increasingly widespread. However, the antenna performance of traditional Bluetooth headsets is poor. Furthermore, in order to meet the demand for compact layout, it is difficult to achieve the requirements of no antenna clearance area or no clearance area for small antennas, resulting in reduced antenna performance.

[0003] Based on advances in chip and Bluetooth technology, true wireless stereo (TWS) Bluetooth earphones eliminate the need for traditional physical wires. Instead, two earbuds form a stereo system via Bluetooth. Simply connect your phone to one of the earbuds, which acts as the receiving end. This receiver wirelessly transmits the stereo signal to the other earbud, completing the stereo system. TWS earbuds are popular with users for their convenience and compact size, and their use is growing.

[0004] TWS Bluetooth headsets are small in size but have many components, and the internal space of the product is limited. How to effectively utilize the internal space of TWS headsets to reduce the impact of product miniaturization on antenna performance has become a current research topic. Summary of the Invention

[0005] An embodiment of the present application provides a Bluetooth headset that can effectively utilize the internal space of the Bluetooth headset and reduce the impact of product miniaturization on antenna performance.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] In the first aspect, a Bluetooth headset is provided. The Bluetooth headset includes an earplug portion and an ear handle portion; the ear handle portion includes a corner portion connected to the earplug portion and an ear handle rod connected to the corner portion, and a battery is provided inside the ear handle rod; the Bluetooth headset includes a flexible circuit board, the flexible circuit board includes a feeding portion and a first extension portion connected to the feeding portion; the feeding portion is provided at the corner portion, and the first extension portion extends to the ear handle rod; the feeding portion is provided with a feeding electrode, a main antenna is provided on the first side of the first extension portion, and at least one touch sensor is provided on the second side of the first extension portion; wherein the first side of the first extension portion faces the battery, the second side of the first extension portion faces the inner wall of the ear handle rod, and the feeding electrode is coupled to the main antenna. In an embodiment of the present application, the touch sensor and the main antenna are respectively provided on both sides of the first extension portion of the flexible circuit board, so that the two can reuse the same space in space, saving the internal space of the Bluetooth headset. In addition, the touch sensor is set on the side close to the inner wall of the ear handle, and the main antenna is set on the side close to the battery, which avoids the antenna blocking the touch sensor, thereby ensuring the normal use of the touch sensor. In addition, the reasonable setting of the position of the touch sensor can ensure the clearance area of ​​the antenna, so that while effectively utilizing the internal space of the Bluetooth headset, the impact of product miniaturization on antenna performance is minimized.

[0008] In some possible implementations, the earbud is provided with a touch control circuit, and the touch sensor is coupled to the touch circuit via a low-pass, high-resistance element. When the touch sensor and main antenna are positioned on either side of the first extension, the touch sensor and main antenna are separated by only the thickness of the first extension. Therefore, when the touch sensor is within the high-frequency signal radiation field of the main antenna, a high-frequency resonant current is generated in the touch sensor, thereby generating in-band noise in the touch sensor. To avoid this problem, the earbud is provided with a touch control circuit, and the touch sensor is coupled to the touch circuit via a low-pass, high-resistance element. The low-pass, high-resistance element can be a choke device, such as a choke inductor or a magnetic bead. This low-pass, high-resistance element blocks the high-frequency resonant current in the touch sensor while ensuring that the low-frequency signal generated by the touch sensor when touched by a person can be transmitted to the touch control circuit through the low-pass, high-resistance element. In this way, the touch sensor acts as a floating trace above the main antenna, minimizing the impact on the main antenna's clearance.

[0009] In some possible implementations, to prevent the high-frequency signal from the main antenna from coupling through the ground trace to the low-pass high-resistance element (of course, when multiple touch sensors are used, this could also be the low-pass high-resistance element coupled to other touch sensors), or the trace between the low-pass high-resistance element and the touch sensor, or the touch sensor, thereby causing in-band noise within the touch sensor and / or such trace, the low-pass high-resistance element, the trace between the low-pass high-resistance element and the touch sensor, and the touch sensor are located at a distance greater than a first threshold from the ground trace on the flexible circuit board. For example, the first threshold is 1 μm. This effectively isolates the low-pass high-resistance element, the trace between the low-pass high-resistance element and the touch sensor, and the touch sensor from the ground trace on the flexible circuit board, minimizing the possibility of the high-frequency signal from the main antenna coupling through the ground trace to the low-pass high-resistance element, or the trace between the low-pass high-resistance element and the touch sensor, or the touch sensor. The ground trace is connected to a common reference ground, which refers to the ground terminals of various components within the Bluetooth headset.

[0010] In some possible implementations, the flexible circuit board further includes a second extension portion connected to the feed portion, a parasitic antenna being provided on the second extension portion, the second extension portion extending to the earplug portion, the feed portion being provided with a ground trace, and the parasitic antenna being coupled to the ground trace. The main antenna and the parasitic antenna can form antennas of different modes on the Bluetooth headset, such as a balanced antenna or an unbalanced antenna. In some examples, a balanced antenna is also referred to as a differential mode (DM) antenna, and an unbalanced antenna is referred to as a common mode (CM) antenna. It is understood that when forming a balanced antenna, the current provided by the RF circuit to the main antenna and the parasitic antenna 60 has different directions. For example, the first current in the main antenna flows from one end connected to the feed electrode to the other end away from the feed electrode, while the second current in the parasitic antenna flows from one end away from the ground trace to the end coupled to the ground trace. When forming an unbalanced antenna, the direction of the current in the main antenna and the parasitic antenna from the RF circuit is the same. For example, the direction of the first current in the main antenna is from the end connected to the feeding electrode to the other end away from the feeding electrode, and the direction of the second current in the parasitic antenna is from the end coupled to the ground trace to the end away from the ground trace.

[0011] In some possible implementations, to adjust the physical length of the path through which current actually flows in the parasitic antenna, the parasitic antenna is coupled to a ground trace via an inductor. Adjusting the inductance of the inductor is equivalent to adjusting the physical length of the path through which current actually flows in the parasitic antenna.

[0012] In some possible implementations, the flexible circuit board includes a third extension portion connected to the feed portion, the third extension portion extending to the earplug portion, and at least one PCB is disposed on the third extension portion; wherein the second extension portion extends between the two PCBs, or the second extension portion extends to a side of the at least one PCB away from the corner portion. To save space, the third extension portion can be extended between the two PCBs. In addition, because the PCB and components disposed thereon contain conductive materials, such as metal components, to avoid affecting the parasitic antenna, the second extension portion extends to a side of the at least one PCB away from the corner portion (i.e., the side of the PCB close to the speaker assembly).

[0013] In some possible implementations, to ensure effective isolation between the touch sensor and the main antenna and minimize coupling of high-frequency signals from the main antenna to the touch sensor, the thickness of the flexible circuit board is greater than or equal to 0.12 mm.

[0014] In some possible implementations, the touch sensor includes touch electrodes; the projection of the touch electrodes of at least one of the touch sensors on the plane where the main antenna is located is located within the area of ​​the main antenna; to ensure the clearance of the main antenna, the total area of ​​the touch electrodes of the at least one touch sensor is smaller than the area of ​​the main antenna.

[0015] In some possible implementations, the flexible circuit board includes a fourth extension portion connected to the feeding portion, wherein the fourth extension portion extends to the ear handle rod; the fourth extension portion is arranged between the first extension portion and the battery; and the battery is coupled to the power line on the fourth extension portion.

[0016] In some possible implementations, the electrical length of the main antenna is 1 / 2. When the antenna of the above-mentioned Bluetooth headset only includes the above-mentioned main antenna, the main antenna constitutes a monopole offset-fed antenna, wherein the electrical length of the main antenna is approximately 1 / 2, where the electrical length refers to the ratio of the physical length of the current flowing through the main antenna to the wavelength of the transmitted electromagnetic wave. Taking the Bluetooth frequency band as an example, it should be noted that "approximately" means that the physical length of the current flowing through the main antenna is approximately equal to half of the wavelength of the electromagnetic wave in the Bluetooth frequency band, that is, the difference between the physical length of the current flowing through the main antenna and half of the wavelength of the electromagnetic wave in the Bluetooth frequency band is within a preset range. In specific implementation, the electrical length can be made equal to one-half by adjusting the matching circuit, but the actual physical length of the current flowing through the main antenna is not necessarily exactly equal to one-half.

[0017] In some possible implementations, the sum of the electrical lengths of the main antenna and the parasitic antenna is 1 / 2.

[0018] In some possible implementations, the electrical length of the main antenna is 1 / 4, and the electrical length of the parasitic antenna is 1 / 4. The sum of the electrical lengths of the main antenna and the parasitic antenna is approximately 1 / 2; for example, the electrical length of the main antenna 40 is approximately 1 / 4, and the electrical length of the parasitic antenna is approximately 1 / 4. Taking the example of the electromagnetic wave wavelength transmitted by the main antenna and the parasitic antenna being the Bluetooth band, it should be noted that "approximately" means that the sum of the physical length of the current flowing through the main antenna and the physical length of the current flowing through the parasitic antenna is approximately equal to half the wavelength of the electromagnetic wave in the Bluetooth band, or that the physical length of the current flowing through the main antenna is approximately equal to one-quarter the wavelength of the electromagnetic wave in the Bluetooth band, and the physical length of the current flowing through the parasitic antenna is approximately equal to one-quarter the wavelength of the electromagnetic wave in the Bluetooth band. That is, the difference between the sum of the physical length of the current flowing through the main antenna and the physical length of the current flowing through the parasitic antenna and one-half the wavelength of the electromagnetic wave in the Bluetooth band is within a preset range. Alternatively, the difference between the physical length of the current flowing through the main antenna and one-quarter the wavelength of the electromagnetic wave in the Bluetooth frequency band is within a preset range, and the difference between the physical length of the current flowing through the parasitic antenna and one-quarter the wavelength of the electromagnetic wave in the Bluetooth frequency band is also within a preset range. In specific implementations, the electrical length can be adjusted to one-half by matching the circuit. However, the sum of the actual physical length of the current flowing through the main antenna and the actual physical length of the current flowing through the parasitic antenna may not be exactly equal to one-half. The actual physical length of the current flowing through the main antenna and the actual physical length of the current flowing through the parasitic antenna may be equal or unequal. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of a Bluetooth headset provided by the prior art;

[0020] Figure 2 The embodiments of this application provide Figure 1 A schematic diagram of a partially exploded structure of a Bluetooth headset shown;

[0021] Figure 3 A schematic diagram of the internal structure of a Bluetooth headset provided in an embodiment of the present application;

[0022] Figure 4 A schematic structural diagram of a flexible circuit board provided in an embodiment of the present application;

[0023] Figure 5 The embodiments of this application provide Figure 4 The schematic diagram of the local structure of the flexible circuit board at position E shown;

[0024] Figure 6 A schematic structural diagram of a first extension portion provided in an embodiment of the present application;

[0025] Figure 7 A schematic diagram of the connection relationship of a touch sensor provided in an embodiment of the present application;

[0026] Figure 8 A schematic diagram of the connection relationship of a parasitic antenna provided in an embodiment of the present application;

[0027] Figure 9 A schematic diagram of the internal structure of a Bluetooth headset provided in another embodiment of the present application;

[0028] Figure 10 A schematic diagram of a partial structure of a fourth extension portion provided in an embodiment of the present application;

[0029] Figure 11 A schematic diagram of a simulation curve of the radiation parameters of the Bluetooth headset antenna provided in an embodiment of the present application;

[0030] Figure 12 A schematic diagram of the current direction of the main antenna and the parasitic antenna when the Bluetooth headset antenna operates in a 2.44 GHz common mode state according to an embodiment of the present application;

[0031] Figure 13 A schematic diagram of the current direction of the main antenna and the parasitic antenna when the Bluetooth headset antenna operates in a 2.44 GHz differential mode according to an embodiment of the present application;

[0032] Figure 14 A schematic diagram of a simulation curve of radiation parameters of a Bluetooth headset antenna provided in another embodiment of the present application. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0034] Unless otherwise defined, all scientific and technological terms used herein have the same meaning as those known to those of ordinary skill in the art. In this application, "at least one" refers to one or more, and "a plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, wherein A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following items" or its similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can represent: a, b, c, a and b, a and c, b and c or a, b and c, wherein a, b and c can be single or multiple. In addition, in the embodiments of the present application, words such as "first" and "second" do not limit quantity and order.

[0035] In addition, in this application, directional terms such as "upper" and "lower" are defined relative to the orientation of the components in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they can change accordingly according to changes in the orientation of the components in the drawings.

[0036] It should be noted that, in this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0037] The antennas (main antenna and parasitic antenna) of the Bluetooth headset provided in the embodiments of the present application can operate in the Bluetooth frequency band, wherein the frequency range of the Bluetooth band is 2402 MHz to 2480 MHz.

[0038] Reference Figure 1 As shown, the embodiment of the present application provides a structural diagram of a Bluetooth headset 100 (the positional relationship of the structures described in each structural diagram is described in association with each other in the three-dimensional coordinate system space composed of XYZ, for example, Figure 1, the Y direction is the longitudinal direction, the X direction is the transverse direction, and the Z direction is the direction perpendicular to the XY plane). Typically, the Bluetooth headset 100 has an earplug portion 1 and an ear handle portion 2. The ear handle portion 2 includes a corner portion 21 connected to the earplug portion 1, and an ear handle rod 22 connected to the corner portion 21. The corner portion 21 and the ear handle rod 22 of the ear handle portion 2 are arranged in the longitudinal direction (Y direction) in sequence. The earplug portion 1 is used to partially embed into the ear of the user's body. When the user wears the Bluetooth headset 100, the earplug portion 1 is partially embedded in the user's ear, and the ear handle portion 2 is located outside the user's ear and contacts the user's ear.

[0039] refer to Figure 1 and Figure 2 As shown, Figure 2 yes Figure 1 The schematic diagram of the partial decomposition structure of the Bluetooth headset 100 is shown. The Bluetooth headset 100 includes a shell 10. The shell 10 is used to accommodate other components of the Bluetooth headset 100 to fix and protect the other components. The shell 10 includes a main shell 101, a bottom shell 102 and a side shell 103. The main shell 101 is partially located at the ear handle part 2 of the Bluetooth headset 100, and partially located at the earplug part 1 of the Bluetooth headset 100. The main shell 101 is formed with a first opening 1011 at one end of the ear handle rod 22 of the Bluetooth headset 100 away from the corner part 21, and a second opening 1012 is formed at the earplug part 1 of the Bluetooth headset 100. The other components of the Bluetooth headset 100 can be loaded into the main shell 101 from the first opening 1011 or the second opening 1012. For example, the speaker assembly 80 can be installed inside the earplug portion 1 of the main shell 101 through the second opening 1012, and the battery 30 can be installed inside the ear handle rod 22 of the main shell 101 through the first opening 1011. Of course, there may be other components that need to be arranged inside the main shell 101, such as: a flexible circuit board 20, one or more printed circuit boards (PCB) 70 (701, 702), and a chip 200 on the PCB 70 (such as a processor, an audio decoder, a radio frequency circuit, a charging circuit, a touch circuit, etc.), a microphone module 90, an antenna (such as the main antenna 40 and the parasitic antenna 60 provided in the embodiments of the present application), a touch sensor ( Figure 4The bottom shell 102 is located at one end of the ear handle rod 22 of the Bluetooth headset 100 away from the corner portion 21 and is fixedly connected to the main shell 101, and the bottom shell 102 is installed in the first opening 1011. The side shell 103 is located in the earplug portion 1 of the Bluetooth headset 100 and is fixedly connected to the main shell 101, and the side shell 103 is installed in the second opening 1012. Among them, the connection between the bottom shell 102 and the main shell 101 is a detachable connection (such as a snap connection, a threaded connection, etc.) to facilitate subsequent repair or maintenance of the Bluetooth headset 100. In other embodiments, the connection between the bottom shell 102 and the main shell 101 can also be a non-detachable connection (such as gluing) to reduce the risk of the bottom shell 102 accidentally falling off, so that the reliability of the Bluetooth headset 100 is higher. The connection between the side shell 103 and the main shell 101 is a detachable connection (such as a snap connection, a threaded connection, etc.) to facilitate subsequent repair or maintenance of the Bluetooth headset 100. In other embodiments, the connection between the side housing 103 and the main housing 101 can also be a non-detachable connection (e.g., adhesive bonding) to reduce the risk of accidental detachment of the side housing 103, thereby increasing the reliability of the Bluetooth headset 100. The side housing 103 is provided with one or more sound holes 1031, so that the sound inside the housing 10 can be transmitted to the outside of the housing 10 through the sound holes 1031. This application does not impose strict restrictions on the shape, position, number, etc. of the sound holes 1031.

[0040] The above describes a typical structure of the Bluetooth headset 100. Of course, the structure of the Bluetooth headset 100 described above is not the only one. In some embodiments, those skilled in the art may also make other structural designs.

[0041] Reference Figure 2 、 Figure 3 as well as Figure 4 As shown, Figure 3 A schematic diagram of the internal structure of the Bluetooth headset 100 is provided. Figure 4 A schematic diagram of the structure of the flexible circuit board 20 is provided. Specifically, the Bluetooth headset 100 includes the flexible circuit board 20, which includes a feeding portion 201 and a first extension portion 202 connected to the feeding portion 201; the feeding portion 201 is provided at the corner portion 21, and the first extension portion 202 extends to the ear handle 22.

[0042] The feeding portion 201 is provided with a feeding electrode 2011, the first side of the first extension portion 202 is provided with a main antenna 40, and the second side of the first extension portion 202 is provided with at least one touch sensor 50 (wherein Figure 4 Take three touch sensors 501, 502, 503) as an example; Figure 6As shown, the first side of the first extension portion 202 faces the battery 30, the second side of the first extension portion 202 faces the inner wall of the ear stem 22, and the feeding electrode 2011 is coupled to the main antenna 40. Figure 4 、 Figure 6 As shown, the main antenna 40 is arranged on a first side of the first extension portion 202 along the extension direction of the first extension portion 202, and at least one touch sensor 50 is arranged sequentially on a second side of the first extension portion 202 along the extension direction of the first extension portion 202. In this way, the RF circuit of the Bluetooth headset 100 can output a transmission signal to the main antenna 40 via the feeding electrode 2011. The transmission signal resonates with the main antenna and radiates into the surrounding space. Of course, the main antenna 40 can also receive RF signals transmitted through space, convert them into electrical signals, and transmit them to the RF circuit, thereby achieving signal transmission. In some embodiments, the RF circuit is also called a transceiver. It should be noted that only one touch sensor 50 can be set on the second side of the first extension part 202. In this case, the user's operation on the touch sensor 50 can be a single click, multiple clicks or long press operation. The touch circuit coupled to the touch sensor 50 can determine whether the user has performed a touch operation on the touch sensor 50 based on the touch signal transmitted by the touch sensor 50, and determine the frequency, duration, intensity and other parameters of the touch based on the electrical signal generated by the touch sensor 50, thereby determining the corresponding operation type, and the processor judges and executes the operation corresponding to the operation type. In addition, when two or more touch sensors 50 (for example, 501, 502, and 503) are provided on the second side of the first extension portion 202, the operation on the two or more touch sensors 50 can be a sliding operation. For example, when the user slides his finger across the touch sensor 501, the touch sensor 502, and the touch sensor 503 in sequence, the touch control circuit coupled to the touch sensor 50 can determine the direction of the user's finger sliding based on the time sequence in which the touch sensor 501, the touch sensor 502, and the touch sensor 503 output touch signals in sequence, thereby determining the corresponding operation type, and the processor determines and executes the operation corresponding to the operation type. For example, when a finger slides upward along the Y direction across touch sensor 501, touch sensor 502, and touch sensor 503 in sequence, the processor determines that the user's finger is sliding upward based on the touch signal detected by the touch circuit, and controls the volume to increase; or when a finger slides downward along the Y direction across touch sensor 503, touch sensor 502, and touch sensor 501 in sequence, the processor determines that the user's finger is sliding downward based on the touch signal detected by the touch circuit, and controls the volume to decrease.

[0043] In the embodiment of the present application, the touch sensor 50 and the main antenna 40 are respectively arranged on either side of the first extension portion 202 of the flexible circuit board 20, thereby spatially reusing the same space for the two and saving internal space in the Bluetooth headset. In addition, the touch sensor 50 is arranged on the side close to the inner wall of the ear handle 22, and the main antenna 40 is arranged on the side close to the battery, thereby preventing the main antenna 40 from blocking the touch sensor 50, thereby ensuring the normal use of the touch sensor 50. In addition, the reasonable positioning of the touch sensor 50 can ensure the clearance area of ​​the main antenna 40. This effectively utilizes the internal space of the Bluetooth headset while minimizing the impact of product miniaturization on antenna performance.

[0044] When the touch sensor 50 and the main antenna 40 are arranged on both sides of the first extension portion 202, since the touch sensor 50 and the main antenna 40 are separated by only the thickness of the first extension portion 202, when the touch sensor is in the high-frequency signal radiation field of the main antenna, a high-frequency resonant current will be generated in the touch sensor, thereby forming in-band noise in the touch sensor. To avoid the above problem, combined with Figure 5 、 Figure 7 As shown, Figure 5 for Figure 4 The partial structural diagram at E in the middle shows that the earplug part 1 is provided with a touch circuit, a touch sensor 50 ( Figure 7 501) is coupled to the touch circuit through a low-pass high-resistance element 2013. The low-pass high-resistance element 2013 can be a choke device, such as a choke inductor or a magnetic bead. In this way, the low-pass high-resistance element 2013 can block the high-frequency resonant current on the touch sensor, and at the same time, ensure that the low-frequency signal generated by the touch sensor 50 when touched by the human body can be transmitted to the touch circuit through the low-pass high-resistance element 2013. In this way, the touch sensor 50 is only equivalent to a trace suspended above the main antenna 40, which can maximize the elimination of the impact on the clearance of the main antenna 40. Combined Figure 4 、 Figure 5 As shown, the touch sensor 501 is connected to the low-pass high-resistance element 2013 via the trace L1, the touch sensor 502 is connected to the low-pass high-resistance element via the trace L2 (not marked in the figure), and the touch sensor 502 is connected to the low-pass high-resistance element via the trace L3 (not marked in the figure). In addition, in order to ensure effective isolation between the touch sensor 50 and the main antenna 40 and to minimize the coupling of high-frequency signals from the main antenna 40 to the touch sensor 50, Figure 6 As shown, the thickness H of the flexible circuit board 20 is greater than or equal to 0.12 mm.

[0045] To prevent the high-frequency signal of the main antenna 40 from being coupled to the low-pass high-resistance element 2013 (of course, when multiple touch sensors are used, this can also be a low-pass high-resistance element coupled to other touch sensors), or the line L1 between the low-pass high-resistance element 2013 and the touch sensor 501 (of course, this can also be line L2 or line L3), or the touch sensors 50 (501, 502, 503) through the ground line GND, thereby causing in-band noise to be generated in the touch sensors and / or the above-mentioned lines, the low-pass high-resistance element, the lines (L1, L2, and L3) between the low-pass high-resistance element and the touch sensors, and the touch sensors 50 (501, 502, 503) are located at a distance greater than a first threshold from the ground line GND on the flexible circuit board 20. For example, the first threshold is 1 μm, where the distance between the low-pass high-resistance element, the traces (L1, L2, and L3) between the low-pass high-resistance element and the touch sensor, and the touch sensor 50 (501, 502, 503), and the ground trace GND on the flexible circuit board 20 refers to the distance between the low-pass high-resistance element, the traces (L1, L2, and L3) between the low-pass high-resistance element and the touch sensor, and the touch sensor 50 (501, 502, 503), and the ground trace GND on the flexible circuit board 20 in the structure (for example, the size of the gap between the low-pass high-resistance element, the traces (L1, L2, and L3) between the low-pass high-resistance element and the touch sensor, and the touch sensor 50 (501, 502, 503), and the ground trace GND on the flexible circuit board 20 in the structure). In this way, the low-pass high-resistance component, the trace between the low-pass high-resistance component and the touch sensor, and the touch sensor are effectively isolated from the ground trace GND on the flexible circuit board, minimizing the possibility of high-frequency signals from the main antenna 40 being coupled to the low-pass high-resistance component, the trace between the low-pass high-resistance component and the touch sensor, or the touch sensor through the ground trace GND. The ground trace GND is connected to a common reference ground, which is the ground terminal of various components within the Bluetooth headset.

[0046] In some examples, such as Figure 4 and Figure 7As shown, the touch sensor 50 (501, 502, 503) includes touch electrodes; that is, the touch sensor 50 uses plate-shaped touch electrodes. To minimize space, the projection of the touch electrodes of at least one touch sensor 50 onto the plane where the main antenna 40 resides is located within the area of ​​the main antenna 40. To ensure clearance for the main antenna 40, the total area of ​​the touch electrodes of the at least one touch sensor is smaller than the area of ​​the main antenna. To ensure clearance for the main antenna 40 and maintain the sensitivity of the touch sensor, the total area of ​​the touch electrodes of the at least one touch sensor is 20% to 80% of the area of ​​the main antenna. In practical applications, while ensuring clearance for the main antenna 40 and maintaining the sensitivity of the touch sensor, the larger the ratio of the total area of ​​the touch electrodes of the at least one touch sensor to the area of ​​the main antenna, the better.

[0047] When the antenna of the Bluetooth headset only includes the main antenna 40, the main antenna 40 constitutes a monopole offset-fed antenna, wherein the electrical length of the main antenna 40 is approximately 1 / 2, where the electrical length refers to the ratio of the physical length of the current flowing through the main antenna 40 to the wavelength of the electromagnetic wave transmitted. Taking the wavelength of the electromagnetic wave transmitted by the main antenna 40 and the parasitic antenna 60 as the Bluetooth frequency band as an example, it should be noted that "approximately" means that the physical length of the current flowing through the main antenna 40 is approximately equal to half of the wavelength of the electromagnetic wave in the Bluetooth frequency band, that is, the difference between the physical length of the current flowing through the main antenna 40 and half of the wavelength of the electromagnetic wave in the Bluetooth frequency band is within a preset range. In specific implementation, the electrical length can be made equal to half by adjusting the matching circuit, but the actual physical length of the current flowing through the main antenna 40 is not necessarily exactly equal to half.

[0048] Reference Figure 4 、 Figure 5 、 Figure 8As shown, the flexible circuit board 20 also includes a second extension portion 203 connected to the feed portion 201. A parasitic antenna 60 is provided on the second extension portion 203. The second extension portion 203 extends to the earplug portion 1. The feed portion 201 is provided with a ground trace GND, and the parasitic antenna 60 is coupled to the ground trace GND. The parasitic antenna 60 is laid along the extension direction of the second extension portion 203 and is connected to the RF circuit via the ground trace GND. In this way, in conjunction with the main antenna 50, the main antenna 50 and the parasitic antenna 60 can form different antenna modes on the Bluetooth headset, such as a balanced antenna or an unbalanced antenna. In some examples, a balanced antenna is also referred to as a differential mode (DM) antenna, and an unbalanced antenna is referred to as a common mode (CM) antenna. It is understood that when forming a balanced antenna, the directions of the currents provided by the RF circuit to the main antenna 40 and the parasitic antenna 60 are different. For example, the direction of the first current in the main antenna 40 is from the end connected to the feed electrode to the other end away from the feed electrode, and the direction of the second current in the parasitic antenna 60 is from the end away from the ground trace GND to the end coupled to the ground trace GND. When forming an unbalanced antenna, the directions of the currents provided by the RF circuit to the main antenna 40 and the parasitic antenna 60 are the same. For example, the direction of the first current in the main antenna 50 is from the end connected to the feed electrode to the other end away from the feed electrode, and the direction of the second current in the parasitic antenna 60 is from the end coupled to the ground trace GND to the end away from the ground trace GND.

[0049] For example, the sum of the electrical lengths of the main antenna 40 and the parasitic antenna 60 is approximately 1 / 2; for example, the electrical length of the main antenna 40 is approximately 1 / 4, and the electrical length of the parasitic antenna 60 is approximately 1 / 4. Taking the example of the electromagnetic wave wavelength transmitted by the main antenna 40 and the parasitic antenna 60 being in the Bluetooth band, it should be noted that "approximately" means that the sum of the physical lengths through which current flows in the main antenna 40 and the physical lengths through which current flows in the parasitic antenna 60 is approximately equal to half the wavelength of the electromagnetic wave in the Bluetooth band, or that the physical lengths through which current flows in the main antenna 40 are approximately equal to one-quarter the wavelength of the electromagnetic wave in the Bluetooth band, and the physical lengths through which current flows in the parasitic antenna 60 are approximately equal to one-quarter the wavelength of the electromagnetic wave in the Bluetooth band. In other words, the difference between the sum of the physical lengths through which current flows in the main antenna 40 and the physical lengths through which current flows in the parasitic antenna 60 and one-half the wavelength of the electromagnetic wave in the Bluetooth band is within a preset range. Alternatively, the difference between the physical length of the current flowing through the main antenna 40 and one-quarter of the wavelength of the electromagnetic wave in the Bluetooth frequency band is within a preset range, and the difference between the physical length of the current flowing through the parasitic antenna 60 and one-quarter of the wavelength of the electromagnetic wave in the Bluetooth frequency band is within a preset range. In specific implementations, the electrical length can be adjusted to one-half by adjusting the matching circuit. However, the sum of the actual physical length of the current flowing through the main antenna 40 and the actual physical length of the current flowing through the parasitic antenna 60 may not be exactly equal to one-half. The actual physical length of the current flowing through the main antenna 40 and the actual physical length of the current flowing through the parasitic antenna 60 may be equal or unequal. In some examples, to adjust the actual physical length of the current flowing through the parasitic antenna 60, the parasitic antenna 60 is coupled to the ground trace GND via an inductor 2012. Adjusting the inductance of the inductor 2012 is equivalent to adjusting the actual physical length of the current flowing through the parasitic antenna 60.

[0050] Reference Figure 3 、 Figure 4 、 Figure 5 、 Figure 9 As shown, the flexible circuit board 20 further includes a third extension portion 204 connected to the feeding portion 201, the third extension portion 204 extends to the earplug portion 1, and at least one PCB 70 (701, 702) is provided on the third extension portion 204; wherein the second extension portion 203 extends between the two PCBs (such as Figure 3 ), or the second extension portion extends to one side of at least one PCB away from the corner portion (as shown Figure 9 As shown). The third extension portion 204 can form one or more bend structures in the earplug portion 1, and the PCB can be connected to the bend structure. The third extension portion 204 is specifically used to transmit signals to the PCB. Figure 3 as well as Figure 9Two PCBs 701 and 702 are shown in FIG. It is understandable that PCB 701 and PCB 702 are used for layout. For example, one or more chips containing the above-mentioned touch circuit, radio frequency circuit, audio decoder and other functional circuits can be respectively set on PCB 701 and PCB 702. One example is that the chip 200 (such as the processor of the Bluetooth headset) can be set on PCB 701. In order to save space, the third extension part 204 can be extended between the two PCBs 701 and 702 (such as FIG. Figure 3 In addition, since the PCB 70 and the components disposed on the PCB 70 contain conductive materials, such as metal components, in order to avoid affecting the parasitic antenna 60, the second extension portion 203 extends to at least one side of the PCB 70 away from the corner portion (i.e., the side of the PCB 701 close to the speaker assembly 80, as shown). Figure 9 shown).

[0051] Reference Figure 3 、 Figure 4 、 Figure 10 As shown, the flexible circuit board 20 includes a fourth extension portion 205 connected to the feeding portion 201, wherein the fourth extension portion 205 extends to the ear stem 22; the fourth extension portion 205 is arranged between the first extension portion 202 and the battery 30; the battery 30 is coupled to the power line on the fourth extension portion 205. Specifically, as Figure 10 As shown, the fourth extension portion 205 is bent at one or more places within the ear handle rod 22, wherein the connection terminal 301 of the battery 30 is coupled to the electrodes (electrodes 2051, 2052, wherein electrode 2051 and electrode 2052 are respectively positive and negative electrodes) provided on the fourth extension portion 205 and connected to the power line. The battery 30 is arranged inside the ear handle rod 22, and the battery 30 is coupled to the chip 200 through the power line. The battery 30 is used to provide power to the Bluetooth headset 100. In this embodiment, the battery 30 is in a strip shape to better accommodate in the main shell 101. In other embodiments, the battery 30 may also be of other shapes. At this time, the connection terminal 301 of the battery 30 is arranged toward the first opening 1011 of the main shell 101, and the connection structure between the connection terminal 301 of the battery 30 and the fourth extension portion 205 is located near the first opening 1011, which is conducive to subsequent maintenance operations on the battery 30. In other embodiments, the connection terminal 301 of the battery 30 may also be arranged toward the corner portion 21. The Bluetooth headset 100 may further include a microphone module 90. The microphone module 90 is located at one end of the ear handle 22 away from the corner portion 21 (e.g. Figure 3The microphone module 90 shown can be located on the side of the battery 30 away from the feeding part 201, specifically at the bend of the fourth extension part 205) or on the PCB 70. The microphone module 90 is used to convert the sound signal into an electrical signal. The microphone module 90 is closer to the bottom shell 102 relative to the battery 30. At this time, when the user wears the Bluetooth headset 100, the sound signal emitted by the user can be received by the microphone module 90 with better quality and faster speed, thereby ensuring the sound reception quality and efficiency of the Bluetooth headset 100. Similarly, it is also more conducive to subsequent maintenance operations on the microphone module 90. In addition, it should be noted that according to the components installed on the ear handle rod 21 of the Bluetooth headset, the fourth extension part 205 can also be provided with other signal lines that provide signals to these components, such as a signal line connecting the microphone module 90.

[0052] The following specific Figure 4 The flexible circuit board is mounted to the main housing to form Figure 3 The structure shown is described in detail as follows: As described above, the flexible circuit board 20 includes a feed portion 201, a first extension portion 202 connected to the feed portion 201, a second extension portion 203, a third extension portion 204, and a fourth extension portion 205. According to installation requirements, the first extension portion 202 extends to the ear stem 22, the second extension portion 203 extends to the earbud portion 1, the third extension portion 204 extends to the earbud portion 1, and the fourth extension portion extends to the ear stem 22. First, the feed portion 201, the first extension portion 202, the second extension portion 203, the third extension portion 204, and the fourth extension portion 205 can be integrally formed. In other embodiments, the feed portion 201, the first extension portion 202, the second extension portion 203, the third extension portion 204, and the fourth extension portion 205 can also be assembled to form a one-piece structure. The flexible circuit board 20 may also include one or more reinforcement plates (not shown). The one or more reinforcement plates are provided in the reinforcement area of ​​the flexible circuit board 20. The reinforcement area of ​​the flexible circuit board 20 is mainly the area in the flexible circuit board 20 that needs to be connected to other components, or the area used to support other components. Secondly, according to the flexible circuit board drawing process, when the feeding part 201, the first extension part 202, the second extension part 203, the third extension part 204, and the fourth extension part 205 are integrally formed, it is necessary to bend the feeding part 201, the first extension part 202, the second extension part 203, the third extension part 204, and the fourth extension part 205 to adapt to the installation shape of the main housing. In the embodiment of the present application, refer to Figure 4As shown, the first extension portion 202 can be bent 90° inwardly (inwardly along the Z direction) along the axis A parallel to the extension direction of the first extension portion 202 at the connection between the first extension portion 202 and the feeding portion 201, and then bent 90° downwardly along the Y direction along the axis D perpendicular to the extension direction of the first extension portion 202 at the connection between the first extension portion 202 and the feeding portion 201; the fourth extension portion 205 can be bent inwardly (inwardly along the Z direction) along the axis B parallel to the extension direction of the fourth extension portion 205 at the connection between the fourth extension portion 205 and the feeding portion 201. The fourth extension portion 205 is bent 90° to the side, and then bent 90° downward along the Y direction along the axis C perpendicular to the extension direction of the fourth extension portion 205 along the connection between the fourth extension portion 205 and the feeding portion 201; the second extension portion 203 can be bent 90° inwardly (inwardly along the Z direction) along the axis A parallel to the extension direction of the first extension portion 202 along the connection between the second extension portion 203 and the feeding portion 201; wherein, the third extension portion 204 needs to be bent into a shape suitable for installation in the earplug portion 1 according to the number and shape of the PCBs connected thereto, which will not be repeated here, and finally formed as shown in FIG. Figure 3 The mounting structure of the flexible circuit board 20 is shown.

[0053] Reference Figure 11 As shown, the embodiments of the present application respectively simulate and test the radiation parameters of the antenna in two cases: the Bluetooth headset only includes the main antenna (case 1) and the Bluetooth headset includes both the main antenna and the parasitic antenna (case 2). Figure 11The figure shows that Curve 1 represents the total efficiency of the antenna in case 1 (total efficiency (tot.eff) = radiation power / input power); Curve 2 represents the total efficiency of the antenna in case 2; Curve 3 represents the radiation efficiency of the antenna in case 1 (radiation efficiency (rad.eff) = radiation power / (input power - antenna loss)); Curve 4 represents the radiation efficiency of the antenna in case 2; Curve 5 represents the loss efficiency of the antenna in case 3; and Curve 6 represents the loss efficiency of the antenna in case 2. It can be seen that in case 1, there is one mode (the main antenna operates in the common mode, i.e., the inflection point of Curves 1, 3, and 5). The optimal position for total efficiency and radiation efficiency (lowest loss) in this mode is between 2.4 GHz and 2.5 GHz. In case 2, there are two modes (the main antenna operates in the common mode, i.e., the inflection point between 2.4 GHz and 2.5 GHz of Curves 2, 4, and 6; the differential mode of the parasitic antenna is i.e., the inflection point between 2.2 GHz and 2.3 GHz of Curves 2, 4, and 6). Among them, the total efficiency sampling of the Bluetooth band frequency points of 2.4GHz, 2.44GHz, and 2.48GHz shows that in case 1, the total efficiency of the antenna is -13.154dB, -11.445GHz, and -11.436GHz, respectively; in case 2, the total efficiency of the antenna is -12.027dB, -11.49GHz, and -11.408GHz, respectively. The antenna total efficiency is obviously higher in case 2. In addition, combining the radiation efficiency curve and the loss curve, it can be seen that in the Bluetooth band, the radiation efficiency in case 2 is higher and the loss efficiency is lower. In addition, case 2 effectively increases the antenna's usable bandwidth.

[0054] Reference Figure 12 、 Figure 13 As shown, the embodiment of the present application includes a main antenna and a parasitic antenna (case 2), and the antenna operates in a differential mode state (DM, Figure 13 ) and common mode state (CM, Figure 12 ), the current direction of the main antenna and the parasitic antenna is simulated. Figure 12 As shown, the direction of the current in the main antenna 40 and the parasitic antenna 60 from the RF circuit is the same. For example, the direction of the first current in the main antenna is from the end connected to the feeding electrode to the other end away from the feeding electrode, and the direction of the second current in the parasitic antenna is from the end coupled to the ground trace GND to the end away from the ground trace GND. Figure 13 As shown, the first current in the main antenna flows from one end connected to the feeding electrode to the other end away from the feeding electrode, and the second current in the parasitic antenna flows from one end away from the ground trace GND to one end coupled to the ground trace GND. Figure 14As shown, curve 7 shows the total efficiency of the antenna in the common mode state, and curve 8 shows the total efficiency of the antenna in the differential mode state; curve 9 shows the loss efficiency of the antenna in the common mode state, and curve 10 shows the loss efficiency of the antenna in the differential mode state. Among them, the total efficiency sampling of the Bluetooth band frequency points 2.4GHz, 2.44GHz, and 2.48GHz shows that in the common mode state, the total efficiency of the antenna is -13.593dB, -12.76GHz, and -12.562GHz respectively; in case 2, the total efficiency of the antenna is -12.027dB, -11.49GHz, and -11.408GHz respectively; it is obvious that the total efficiency is higher in the differential mode state. And combining curves 9 and 10, it can be seen that in the Bluetooth band, the loss efficiency is lower in the differential mode state. In other words, the antenna performance is better in the differential mode state.

[0055] Although the present application has been described with reference to specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Accordingly, this specification and the drawings are merely illustrative of the present application as defined by the appended claims and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, those skilled in the art may make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, the present application is intended to include such modifications and variations as fall within the scope of the claims of the present application and their equivalents.

Claims

1. A Bluetooth headset, characterized in that: The earbud comprises an earplug portion and an ear handle portion; the ear handle portion comprises a corner portion connected to the earplug portion, and an ear handle rod connected to the corner portion, wherein a battery is provided inside the ear handle rod; The Bluetooth headset includes a flexible circuit board, and the flexible circuit board includes a feeding part and a first extending part connected to the feeding part; the feeding part is provided at the corner portion, and the first extending part extends to the ear handle rod; The feeding portion is provided with a feeding electrode, a main antenna is provided on a first side of the first extension portion, and at least one touch sensor is provided on a second side of the first extension portion; wherein the first side of the first extension portion faces the battery, the second side of the first extension portion faces the inner wall of the ear handle, and the feeding electrode is coupled to the main antenna; The touch sensor includes a touch electrode; The projection of the touch electrode of at least one touch sensor on the plane where the main antenna is located is located within the area of ​​the main antenna; the total area of ​​the touch electrodes of the at least one touch sensor is smaller than the area of ​​the main antenna, and the total area of ​​the touch electrodes of the at least one touch sensor is 20% to 80% of the area of ​​the main antenna.

2. The Bluetooth headset according to claim 1, characterized in that The earplug part is provided with a touch circuit, and the touch sensor is coupled to the touch circuit via a low-pass high-resistance element.

3. The Bluetooth headset according to claim 2, characterized in that The low-pass high-resistance element includes a choke inductor.

4. The Bluetooth headset according to claim 2, characterized in that The distance between the low-pass high-resistance element, the wiring between the low-pass high-resistance element and the touch sensor, and the touch sensor and the ground wiring on the flexible circuit board is greater than a first threshold.

5. The Bluetooth headset according to claim 4, characterized in that: The first threshold is 1 μm.

6. The Bluetooth headset according to claim 1, wherein: The flexible circuit board also includes a second extension portion connected to the feeding portion, a parasitic antenna is provided on the second extension portion, the second extension portion extends to the earplug portion, the feeding portion is provided with a ground trace, and the parasitic antenna is coupled to the ground trace.

7. The Bluetooth headset according to claim 6, characterized in that: The parasitic antenna is coupled to the ground trace through an inductor.

8. The Bluetooth headset according to claim 6, characterized in that: The flexible circuit board includes a third extending portion connected to the feeding portion, the third extending portion extends to the earplug portion, and at least one PCB is provided on the third extending portion; The second extending portion extends between the two PCBs, or the second extending portion extends to a side of the at least one PCB away from the corner portion.

9. The Bluetooth headset according to claim 1, wherein: The thickness of the flexible circuit board is greater than or equal to 0.12 mm.

10. The Bluetooth headset according to claim 1, wherein: The flexible circuit board includes a fourth extension portion connected to the feeding portion, wherein the fourth extension portion extends to the ear handle rod; the fourth extension portion is arranged between the first extension portion and the battery; The battery is coupled to the power line on the fourth extension.

11. The Bluetooth headset according to claim 1, wherein: The electrical length of the main antenna is 1 / 2.

12. The Bluetooth headset according to claim 6, characterized in that The sum of the electrical lengths of the main antenna and the parasitic antenna is 1 / 2.

13. The Bluetooth headset according to claim 6, characterized in that The electrical length of the main antenna is 1 / 4, and the electrical length of the parasitic antenna is 1 / 4.

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