Wearing state detection sensor, headphone and audio equipment

Abstract

The utility model relates to the technical field of electronic equipment, in particular to a wearing state detection sensor, a headphone and audio equipment. The sensor comprises a wearing detection antenna, a directional coupler, a coupling signal detection circuit and a detection chip, the wearing detection antenna is connected with a coupling port of the directional coupler, the output end of the directional coupler is connected with the input end of the coupling signal detection circuit, and the output end of the coupling signal detection circuit is connected with the input end of the detection chip. The wearing detection antenna changes the antenna impedance when the human ear approaches, further changes the radio frequency power output by the directional coupler, and uses the coupling signal detection circuit to convert the radio frequency power into a voltage amplitude to detect the approaching and leaving conditions of the human ear, so as to judge whether the headset is worn, thereby achieving the low-cost and high-reliability headset wearing detection function.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic devices, in particular to a wearing state detection sensor, a headphone and an audio device. Background Art

[0002] In the digital age, headphone is becoming more and more popular. Whether it is for commuting, entertainment, sports or work, high-quality audio experience can add fun to our daily life, and the functions of headphone are becoming increasingly rich and perfect. In order to improve the user experience and the intelligence level of the product, the wearing detection function of headphone has become an indispensable part of the design of modern headphone.

[0003] At present, the detection schemes for wearing of headphone on the market usually adopt sensors and algorithms, including optical detection scheme, pressure detection scheme and capacitive detection scheme. Among them, the optical detection scheme uses a photoelectric sensor to detect whether the headphone is worn on the head, and judges the position and angle of the headphone by detecting the reflection of light. The pressure detection scheme installs a pressure sensor inside the headphone to monitor in real time whether the headphone is in close contact with the head, so as to judge whether the wearing state of the headphone is normal. The capacitive detection scheme utilizes the principle that when a dielectric material is inserted into a capacitor with two electrodes, the area of the electrode plate, the dielectric thickness and the dielectric constant can determine the capacitance value. When a human body approaches, the equivalent dielectric thickness and the dielectric constant change, thus changing the capacitance value. Then, the capacitance change is converted into the corresponding distance through the detection mechanism. However, the above schemes have problems such as high manufacturing cost, easy misjudgment and environmental sensitivity, which affect the user experience.

[0004] The above content is only used to assist in understanding the technical solution of the utility model, and does not represent an admission that the above content is prior art. Summary of the Utility Model

[0005] The main purpose of the utility model is to provide a wearing state detection sensor, a headphone and an audio device, aiming to solve the technical problem that the wearing condition recognition of head-mounted products in the prior art is environmentally sensitive and prone to misjudgment.

[0006] To achieve the above object, the technical solution of the present utility model proposes a wearing state detection sensor, a headphone and an audio device. The wearing state detection sensor includes: a wearing detection antenna, a directional coupler, a coupled signal detection circuit and a detection chip; the wearing detection antenna is connected to the coupling port of the directional coupler, the output end of the directional coupler is connected to the input end of the coupled signal detection circuit, and the output end of the coupled signal detection circuit is connected to the input end of the detection chip; the directional coupler is used to sense the antenna impedance of the wearing detection antenna and output a radio frequency power signal corresponding to the antenna impedance to the coupled signal detection circuit; the wearing detection antenna changes the antenna impedance in response to the change in the distance from the human ear; the coupled signal detection circuit is used to receive the radio frequency power signal, convert the radio frequency power signal into a detection voltage signal, and transmit the detection voltage signal to the detection chip; the detection chip is used to receive the detection voltage signal and determine that the headphone is in a worn state when the amplitude of the detection voltage signal is within a preset amplitude range. By changing the antenna impedance when the human ear approaches through the wearing detection antenna, thereby changing the magnitude of the radio frequency power output by the directional coupler, and using the coupled signal detection circuit to convert it into a voltage amplitude to detect the approach and departure of the human ear, and then determine whether the headphone is worn, realizing a headphone wearing detection function with low cost and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0008] Figure 1 It is a schematic structural diagram of the first embodiment of the wearing state detection sensor of the present utility model;

[0009] Figure 2 It is a schematic structural diagram of the second embodiment of the wearing state detection sensor of the present utility model;

[0010] Figure 3 It is a schematic structural diagram of the directional coupler in the second embodiment of the wearing state detection sensor of the present utility model;

[0011] Figure 4 It is a schematic structural diagram of the third embodiment of the wearing state detection sensor of the present utility model.

[0012] The realization of the object, functional features and advantages of the present utility model will be further described with reference to the embodiments and the drawings. Specific Embodiments

[0013] It should be understood that the specific embodiments described herein are merely used to explain the present utility model and are not intended to limit the present utility model.

[0014] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0015] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present utility model are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If this specific posture changes, then the directional indications will also change accordingly.

[0016] In addition, the descriptions involving "first", "second", etc. in the present utility model are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions appears to be contradictory or unable to be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0017] Refer to Figure 1 , Figure 1 is a schematic structural diagram of the first embodiment of the wearing state detection sensor of the present utility model. The first embodiment of the wearing state detection sensor of the present utility model is proposed.

[0018] In this embodiment, the wearing state detection sensor includes: a wearing detection antenna 10, a directional coupler 20, a coupled signal detection circuit 30, and a detection chip 40; wherein, the wearing detection antenna 10 is connected to the coupling port of the directional coupler 20, the output end of the directional coupler 20 is connected to the input end of the coupled signal detection circuit 30, and the output end of the coupled signal detection circuit 30 is connected to the input end of the detection chip 40.

[0019] It should be noted that the directional coupler 20 can be used to sense the antenna impedance of the wearing detection antenna 10 and output a radio frequency power signal corresponding to the antenna impedance to the coupled signal detection circuit 30. Among them, the wearing detection antenna 10 responds to the change of the antenna impedance with the change of the distance from the human ear.

[0020] It should be understood that the directional coupler 20 can be an electronic component in which two transmission microstrip lines are placed close to each other so that the power on one microstrip line can be coupled to affect the other microstrip line. The wearing detection antenna 10 can change its impedance according to the distance from the human ear. For example, in a possible implementation: the antenna impedance can increase as the distance from the human ear approaches, and has an impedance of 50 ohms when the human ear touches the wearing detection antenna 10. As the impedance of the wearing detection antenna 10 changes, the coupling attenuation amount between the two transmission microstrip lines of the directional coupler 20 will also change. Refer to Table 1, where Table 1 shows the coupling attenuation amounts of directional couplers with different coupling degrees in the case of the simulated human ear being close (i.e., the headphone is worn, LOAD) and the human ear being far away (i.e., the headphone is not worn, OPEN).

[0021]

[0022] Among them, taking a 20dB directional coupler as an example, when the human ear is close (i.e., the headphone is worn, LOAD), the antenna impedance is large, and the coupling attenuation amount of the directional coupler is 46dB@2.4GHz. When the human ear is far away (i.e., the headphone is not worn, OPEN), the coupling attenuation amount of the directional coupler becomes 20dB@2.4GHz. There is a difference of 26dB in the coupling attenuation amounts of the directional coupler in the worn and unworn states.

[0023] Furthermore, the coupled signal detection circuit 30 can be used to receive the radio frequency power signal, convert the radio frequency power signal into a detection voltage signal, and transmit the detection voltage signal to the detection chip 40.

[0024] It should be noted that the greater the coupling attenuation amount of the directional coupler, the greater the energy flowing from the input port to the output port of the directional coupler, that is, the greater the amplitude of the radio frequency power signal. The coupled signal detection circuit 30 can convert the power amplitude of the radio frequency power signal into the voltage amplitude of the detection voltage signal for subsequent judgment and detection functions. The coupled signal detection circuit 30 can use functional elements such as a logarithmic detection circuit, a peak detection circuit, or a power meter to achieve the conversion of power to voltage, which is not specifically limited in this embodiment. For example, when the coupling attenuation amount of the directional coupler is -24dB, the amplitude of the detection voltage signal of the coupled signal detection circuit can be 1.2V, and when the coupling attenuation amount of the directional coupler is -36dB, the amplitude of the detection voltage signal of the coupled signal detection circuit can be 0.8V.

[0025] Further, the detection chip 40 can be used to receive the detection voltage signal, and when the amplitude of the detection voltage signal is within a preset amplitude range, it is determined that the headphone is in a worn state.

[0026] It should be noted that the detection chip 40 can be an electronic component with data transmission and data processing functions, with a processor and a memory inside, capable of processing the input signal through a software program pre-stored inside, and storing the processing result or outputting it in the form of an electrical signal. For example, a Micro Control Unit (MCU) or a System on Chips (SOC) can be used. The preset amplitude range can be the voltage amplitude range preset in the detection chip 40. For example, it can be set that when the amplitude of the received detection voltage signal is lower than 0.8V, it is determined that the headphone is in a worn state, and when the amplitude of the received detection voltage signal is higher than 0.8V, it is determined that the headphone is not in a worn state. The preset amplitude range can also be set to 0.8 - 1V. For example, according to the corresponding relationship between the coupling attenuation and the amplitude of the detection voltage signal in the previous test stage, it is determined that when the detection voltage signal is 1V, the distance between the headphone and the human ear is 2cm, and when the detection voltage signal is 0.9V, the distance between the headphone and the human ear is 1cm.

[0027] In this embodiment, a wearing state detection sensor is proposed. The wearing state detection sensor includes: a wearing detection antenna, a directional coupler, a coupled signal detection circuit, and a detection chip; the wearing detection antenna is connected to the coupling port of the directional coupler, the output end of the directional coupler is connected to the input end of the coupled signal detection circuit, and the output end of the coupled signal detection circuit is connected to the input end of the detection chip; the directional coupler is used to sense the antenna impedance of the wearing detection antenna and output a radio frequency power signal corresponding to the antenna impedance to the coupled signal detection circuit; the wearing detection antenna changes the antenna impedance in response to the change in the distance from the human ear; the coupled signal detection circuit is used to receive the radio frequency power signal, convert the radio frequency power signal into a detection voltage signal, and transmit the detection voltage signal to the detection chip; the detection chip is used to receive the detection voltage signal, and when the amplitude of the detection voltage signal is within a preset amplitude range, it is determined that the headphone is in a worn state. By changing the antenna impedance when the human ear approaches through the wearing detection antenna, and then changing the magnitude of the radio frequency power output by the directional coupler, using the coupled signal detection circuit to convert it into a voltage amplitude to detect the approach and departure of the human ear, and then determine whether the headphone is worn, realizing a headphone wearing detection function with low cost and high reliability.

[0028] Refer toFigure 2 , Figure 2 This is a schematic structural diagram of the second embodiment of the wearing state detection sensor of the present utility model. The second embodiment of the wearing state detection sensor of the present utility model is proposed based on the first embodiment of the above-mentioned wearing state detection sensor.

[0029] The wearing state detection sensor further includes: a driving unit 50; an output end of the driving unit 50 is connected to an input end of the directional coupler 20;

[0030] It should be noted that the driving unit 50 can be used to generate a driving signal and transmit it to the directional coupler 20; the directional coupler 20 can also be used to output the radio frequency power signal to the coupled signal detection circuit when receiving the driving signal.

[0031] It should be understood that the driving signal can be an electrical signal for driving the directional coupler to work. To improve the battery life of the headphone, the wearing status of the headphone can be judged only when detection is required, and at the same time, the impedance of other parts of the headphone during operation is avoided from interfering with the detection result.

[0032] Further, the driving unit 50 includes: a Bluetooth chip 501 and a radio frequency switch chip 502; an output end of the Bluetooth chip is connected to an input end of the radio frequency switch chip, a first output end of the radio frequency switch chip is connected to a Bluetooth antenna, and a second output end of the radio frequency switch chip is connected to an input end of the directional coupler.

[0033] It should be noted that the radio frequency switch chip can be used to transmit the Bluetooth transmission signal to the Bluetooth antenna when receiving the Bluetooth transmission signal of the Bluetooth chip; the radio frequency switch chip can also be used to transmit the driving signal to the directional coupler when not receiving the Bluetooth transmission signal of the Bluetooth chip.

[0034] It should be understood that the headphone can perform wireless communication with an external electronic device through the Bluetooth antenna. The Bluetooth chip processes the wireless communication signal, and the Bluetooth chip can also share the chip with the above-mentioned detection chip to save the volume of the headphone. To avoid affecting the normal operation of the headphone, the radio frequency switch chip only transmits the driving signal to the directional coupler when the Bluetooth chip receives the wireless communication signal of the external electronic device, and starts the wearing detection function of the headphone.

[0035] Refer to Figure 3 , Figure 3This is a schematic structural diagram of a directional coupler in the second embodiment of the wearing state detection sensor of the present utility model. The directional coupler includes: a channel line, a coupling line, and a dielectric substrate; the channel line and the coupling line are disposed on the dielectric substrate; the input end of the channel line is connected to the second output end of the RF switch chip, the output end of the channel line is connected to the detection chip, and the coupling line is connected to the wearing detection antenna. The impedance of the wearing detection antenna can be set to 50 ohms to increase the difference in coupling attenuation when the earphone is worn and not worn, thereby improving the accuracy of the detection result.

[0036] In this embodiment, the wearing state detection sensor further includes: a driving unit; the output end of the driving unit is connected to the input end of the directional coupler; the driving unit can be used to generate a driving signal and transmit it to the directional coupler; the directional coupler outputs the RF power signal to the coupling signal detection circuit when receiving the driving signal. Wherein, the driving unit includes: a Bluetooth chip and an RF switch chip; the output end of the Bluetooth chip is connected to the input end of the RF switch chip, the first output end of the RF switch chip is connected to the Bluetooth antenna, and the second output end of the RF switch chip is connected to the input end of the directional coupler; the RF switch chip is used to transmit the Bluetooth transmission signal to the Bluetooth antenna when receiving the Bluetooth transmission signal of the Bluetooth chip; the RF switch chip is further used to transmit the driving signal to the directional coupler when not receiving the Bluetooth transmission signal of the Bluetooth chip. Reduce the material cost and manufacturing cost of the headphone with the wearing recognition function, and realize a reliable, low-power and non-wearing misrecognition solution.

[0037] Refer to Figure 4 , Figure 4 This is a schematic structural diagram of the third embodiment of the wearing state detection sensor of the present utility model. The third embodiment of the wearing state detection sensor of the present utility model is proposed based on the above embodiments of the wearing state detection sensor.

[0038] The coupled signal detection circuit 30 can be selected as a double-peak detection circuit to detect the AC radio frequency power signal and generate a stable AC peak value, which is the detection voltage signal. The coupled signal detection circuit 30 includes: a first capacitor C1, a second capacitor C2, a first diode D1, a second diode D2, and a first resistor R. The first end of the first capacitor C1 is connected to the output end of the directional coupler 20. The second end of the first capacitor C1 is connected to the negative electrode of the first diode D1 and the positive electrode of the second diode D2. The positive electrode of the first diode D1 is grounded. The negative electrode of the second diode D2 is connected to the first end of the first resistor R. The second end of the first resistor R is grounded. The second capacitor C2 is arranged in parallel with the first resistor R. The first end of the first resistor R is also connected to the input end of the detection chip 40.

[0039] It should be noted that the coupled signal detection circuit 30 utilizes the charge and discharge function of the capacitor. When the AC signal is in the positive half cycle, the diode is short-circuited, and the radio frequency power signal is directly applied to the second capacitor for charging. After the voltage on the capacitor reaches the peak value, the amplitude of the AC signal gradually decreases, and the electrical energy stored in the second capacitor discharges to the first resistor. In the negative half cycle of the AC signal, the diode is cut off, and the capacitor continuously discharges slowly to the first resistor. Therefore, a detection voltage signal with a relatively stable amplitude is output on the second capacitor.

[0040] Furthermore, the coupled signal detection circuit 30 further includes: an operational amplifier OP. The input end of the operational amplifier OP is connected to the first end of the first resistor R. The output end of the operational amplifier OP is connected to the input end of the detection chip 40. The low-amplitude detection voltage signal can be amplified according to the gain multiple of the operational amplifier to facilitate the accurate judgment of the headphone wearing condition.

[0041] Furthermore, the wearing state detection sensor further includes: an analog-to-digital converter ADC. The input end of the analog-to-digital converter ADC is connected to the output end of the coupled signal detection circuit 30. The output end of the analog-to-digital converter is connected to the detection chip.

[0042] It should be noted that the analog-to-digital converter can convert the analog electrical signal into a digital electrical signal and then transmit it to the detection chip for wearing detection. The sensor can also be combined with a gyroscope sensor to provide a more reliable and better-quality identification. By judging the headphone wearing condition, the play / pause, call switching, active noise cancellation on and off of the wearing linkage function can be realized to improve the user experience.

[0043] In this embodiment, the coupled signal detection circuit includes: a first capacitor, a second capacitor, a first diode, a second diode, and a first resistor; a first end of the first capacitor is connected to an output end of the directional coupler, a second end of the first capacitor is connected to a negative electrode of the first diode and a positive electrode of the second diode, a positive electrode of the first diode is grounded, a negative electrode of the second diode is connected to a first end of the first resistor, a second end of the first resistor is grounded, the second capacitor is arranged in parallel with the first resistor, and the first end of the first resistor is further connected to an input end of the detection chip. Combining with the gyroscope sensor will provide more reliable and better quality. And it can reduce the material cost and manufacturing cost of the headphone with a wearing recognition function, improving the cost competitiveness of the product; effectively solve the problem of incorrect wearing recognition caused by different temperature and humidity environments of the capacitive sensor, and further solve the user experience problems of play / pause, call switching, active noise reduction on and off of the wearing linkage function.

[0044] In addition, an embodiment of the present invention further provides a headphone. The headphone includes the wearing state detection sensor as described above.

[0045] Furthermore, an embodiment of the present invention further provides an audio device. The audio device includes the wearing state detection sensor as described above or the headphone as described above.

[0046] Since the test device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated one by one here.

[0047] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made by using the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A wearing state detection sensor, characterized in that, The wearing state detection sensor is applied to a headphone, and the wearing state detection sensor includes: a wearing detection antenna, a directional coupler, a coupled signal detection circuit, and a detection chip; The wearing detection antenna is connected to the coupling port of the directional coupler, the output end of the directional coupler is connected to the input end of the coupled signal detection circuit, and the output end of the coupled signal detection circuit is connected to the input end of the detection chip; The directional coupler is configured to sense the antenna impedance of the wearing detection antenna and output a radio frequency power signal corresponding to the antenna impedance to the coupled signal detection circuit; The wearing detection antenna responds to the change in the distance from the human ear to change the antenna impedance; The coupled signal detection circuit is configured to receive the radio frequency power signal, convert the radio frequency power signal into a detection voltage signal, and transmit the detection voltage signal to the detection chip; The detection chip is configured to receive the detection voltage signal and determine that the headphone is in a wearing state when the amplitude of the detection voltage signal is within a preset amplitude range.

2. The wearing state detection sensor according to claim 1, wherein The wearing state detection sensor further includes: a driving unit; The output end of the driving unit is connected to the input end of the directional coupler; The driving unit is configured to generate a driving signal and transmit it to the directional coupler; The directional coupler is further configured to output the radio frequency power signal to the coupled signal detection circuit when receiving the driving signal.

3. The wearing state detection sensor according to claim 2, wherein, The driving unit includes: a Bluetooth chip and a radio frequency switch chip; The output end of the Bluetooth chip is connected to the input end of the radio frequency switch chip, the first output end of the radio frequency switch chip is connected to a Bluetooth antenna, and the second output end of the radio frequency switch chip is connected to the input end of the directional coupler; The radio frequency switch chip is configured to transmit the Bluetooth transmission signal to the Bluetooth antenna when receiving the Bluetooth transmission signal of the Bluetooth chip; The radio frequency switch chip is further configured to transmit the driving signal to the directional coupler when not receiving the Bluetooth transmission signal of the Bluetooth chip.

4. The wearing state detection sensor according to claim 3, wherein The directional coupler includes: a channel line, a coupling line, and a dielectric substrate; The channel line and the coupling line are disposed on the dielectric substrate; The input end of the channel line is connected to the second output end of the radio frequency switch chip, the output end of the channel line is connected to the detection chip, and the coupling line is connected to the wearing detection antenna.

5. The wearing state detection sensor according to claim 1, wherein The coupled signal detection circuit includes: a first capacitor, a second capacitor, a first diode, a second diode, and a first resistor; The first end of the first capacitor is connected to the output end of the directional coupler, the second end of the first capacitor is connected to the negative electrode of the first diode and the positive electrode of the second diode, the positive electrode of the first diode is grounded, the negative electrode of the second diode is connected to the first end of the first resistor, the second end of the first resistor is grounded, the second capacitor is arranged in parallel with the first resistor, and the first end of the first resistor is further connected to the input end of the detection chip.

6. The wearing state detection sensor according to claim 5, wherein, The coupled signal detection circuit further includes: an operational amplifier; The input terminal of the operational amplifier is connected to the first end of the first resistor, and the output terminal of the operational amplifier is connected to the input terminal of the detection chip.

7. The wearing state detection sensor according to claim 1, wherein The wearing state detection sensor further includes: an analog-to-digital converter; The input terminal of the analog-to-digital converter is connected to the output terminal of the coupled signal detection circuit, and the output terminal of the analog-to-digital converter is connected to the detection chip.

8. The wearing state detection sensor according to claim 1, wherein The antenna impedance of the wearing detection antenna increases as the distance from the human ear approaches; The amplitude of the radio frequency power signal decreases as the antenna impedance increases; The amplitude of the detection voltage signal decreases as the radio frequency power signal decreases; The detection chip is further configured to determine that the headphone is in a wearing state when the amplitude of the detection voltage signal is lower than the upper limit of the preset amplitude range.

9. A headphone, characterized in that, The headphone includes: the wearing state detection sensor according to any one of claims 1-8.

10. An audio device, characterized in that, The audio device includes: the wearing state detection sensor according to any one of claims 1-8.

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