CN107623881A - A bluetooth headset - Google Patents

Abstract

The invention discloses a bluetooth earphone, which relates to bluetooth communication technology, comprising: a casing and a circuit structure, wherein the casing includes a front cover and a back cover fitted with the front cover; the circuit structure is accommodated in the The internal space formed by the closure of the front cover and the rear cover; the circuit structure includes a main board, an antenna, a power supply, a speaker and a microphone; the main board is electrically connected to the antenna, the speaker and the microphone respectively; The power supply supplies power to the main board, the antenna, the loudspeaker and the microphone respectively; an audio processing circuit, a clock oscillator, a filter and a coupling circuit are arranged on the main board. By adopting the above technical solution, due to the addition of the coupling circuit, the attenuation of the signal during the transmission process can be reduced as much as possible, and the transmission effect is better.

Description

A bluetooth headset

technical field

The invention relates to bluetooth communication technology, in particular to a bluetooth earphone.

Background technique

Bluetooth headset is a wearable device for listening to music and making calls. When you are resting, wear the headset, play your favorite music, and enjoy the happiness that music brings to you. When you make contact with your mobile phone, you don’t need to hold your mobile phone to answer the call. , You can answer calls directly through the Bluetooth headset. And its small size and practicality add more convenience to life.

Existing bluetooth earphones are usually built with audio integrated circuits, and audio transmission is realized on the built 2.4G transmission channel. Other devices communicate with the Bluetooth headset through the Bluetooth protocol. When other devices establish a connection with the Bluetooth headset, other devices send audio signals to the Bluetooth headset. The Bluetooth headset receives electromagnetic waves through the antenna and converts them into modulated wave currents. The audio current taken out of the detector is converted into sound energy, and people can refer to music or language sent by other devices. The Bluetooth headset can also send signals to other devices through operation to realize intelligent control of communication.

However, in the prior art, since earphones are getting smaller and smaller, poor call quality has always been a shortcoming. Due to the small size of the Bluetooth headset, the MICROPHONE (microphone) is far away from the mouth when wearing it, and it is impossible to accurately collect the sound emitted by the human body. Simply considering increasing the number of MICROPHONEs and changing the structure size of the MICROPHONE cannot effectively solve this problem. kind of problem.

At the same time, most of the existing products are designed with the chip of CSR Company, and in the process of binaural wireless communication, the left and right disconnection is easy to occur. And because the 2.4G signal frequency band used is a public frequency band, it is easy to cause mutual influence with WIFI and other signals. Moreover, all wearable devices are powered by lithium batteries, and the instability of the power supply will cause the instability of the signal, which is prone to disconnection.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for improving call quality and a Bluetooth earphone with good call quality.

In order to solve the problems of the technologies described above, the technical solution of the present invention is:

A bluetooth headset, comprising:

A casing and a circuit structure, wherein the casing includes a front cover and a rear cover fitted with the front cover; the circuit structure is accommodated in an internal space formed by closing the front cover and the rear cover; the The circuit structure includes a main board, an antenna, a power supply, a speaker and a microphone; the main board is electrically connected to the antenna, the loudspeaker and the microphone respectively; the power supply is respectively the main board, the antenna, the loudspeaker and The microphone is powered; the main board is provided with an audio processing circuit, a clock oscillator, a filter and a coupling circuit.

Preferably, the circuit structure further includes a touch device; the touch device is electrically connected to the power supply and the main board; the touch device includes a touch panel and a touch switch; an invisible touch area is provided on the rear cover In other words, the touch switch disposed on the touch panel inside the housing can be controlled through the invisible touch area outside the housing.

More preferably, the circuit structure further includes a bluetooth display light, the bluetooth display light is electrically connected to the power supply and the main board, and the rear cover is provided with a through hole for accommodating the bluetooth display light.

More preferably, both the speaker and the microphone are provided with waterproof and sound-permeable nets.

Preferably, the power supply includes a power board, a battery, and a charging interface arranged on the power board; the battery is installed on a battery bracket, and the battery bracket fixes the battery and the power board on the shell body interior.

Preferably, the speaker includes one of a moving iron speaker, a moving coil speaker, an isomagnetic speaker, an electrostatic speaker and an electret speaker.

Preferably, the audio processing circuit includes one of CSR8670, CSR8645 and CSR8675.

Preferably, the antenna includes a PIFA antenna.

By adopting the above technical solution, due to the addition of the coupling circuit, the attenuation of the signal during the transmission process can be reduced as much as possible, and the transmission effect is better.

Description of drawings

Fig. 1 is the structural representation of bluetooth earphone of the present invention;

Fig. 2 is the perspective view of bluetooth earphone of the present invention;

Fig. 3 is the front view of the bluetooth earphone of the present invention;

Fig. 4 is the back view of bluetooth earphone of the present invention;

Fig. 5 is the top view of bluetooth earphone of the present invention;

Fig. 6 is the circuit diagram of the audio processing circuit of the embodiment of the present invention;

7 is a circuit diagram of a power management circuit according to an embodiment of the present invention; and

FIG. 8 is a circuit diagram of a touch device circuit according to an embodiment of the present invention.

In the figure, 1-shell, 11-front cover, 12-back cover, 121-invisible touch area, 122-through hole, 2-circuit structure, 21-main board, 22-microphone, 23-earphone, 24-power supply, 241-Power board, 242-Battery device, 243-Charging interface, 244-Battery holder, 25-Touch device, 26-Bluetooth display light, 27-Waterproof and sound-permeable mesh, 28-Silicone earplugs.

detailed description

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings. It should be noted here that the descriptions of these embodiments are used to help understand the present invention, but are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not constitute a conflict with each other.

As a first embodiment of the present invention, a bluetooth headset, as shown in Figures 1-5, includes: a housing 1 and a circuit structure 2, wherein the housing 1 includes a front cover 11 and a rear cover fitted with the front cover 11 12; the circuit structure 2 is accommodated in the internal space formed by the closure of the front cover 11 and the rear cover 12; the circuit structure 2 includes a main board 21, an antenna (not shown in the figure), a power supply 24, a loudspeaker 23 and a microphone 22; the main board 21 and Antenna, loudspeaker 23 and microphone 22 are electrically connected; power supply 24 supplies power to mainboard 21, antenna, loudspeaker 23 and microphone 22 respectively; mainboard 21 is provided with audio processing circuit, clock oscillator, filter and coupling circuit; The position of the speaker 23 is provided with a silicone earplug 28.

Wherein, the loudspeaker 23 of the present embodiment selects the moving iron loudspeaker to realize better conversation sound quality, of course the loudspeaker 23 can also select a kind of moving coil loudspeaker, isomagnetic loudspeaker, electrostatic loudspeaker and electret loudspeaker in addition to choosing the moving iron loudspeaker .

Continue as shown in Figure 1, the power supply 24 includes a power board 241, a battery 242 and a charging interface 243 arranged on the power board; in order to better fix the battery 242 in the housing 1, the battery 242 is installed on the battery holder 244 Inside, the battery holder 244 fixes the battery 242 together with the power board 241 inside the casing 1 .

As shown in Figure 6, the audio processing circuit uses the CSR8670 of CSR Company. Of course, the audio processing circuit can also use any model of the CSR86XX series. Remove the 1.8V power supply and 1.35V power supply inside the CSR8670, and use an external power supply for power supply, as shown in Figure 6 and 7: disconnect J7 and J9 pins, connect J8 and J6 to the ground wire, and connect the rest of the power supply detection pins Both are connected to an external power supply. The battery generates a set of 1.8V power supply and a set of 1.35V power supply through U5 to make the CSR8670 work normally; by removing the internal power supply, the clutter generated when the internal power module of the CSR8670 is converted is eliminated, so that the transmission of the RF signal is not affected, greatly Reduce the possibility of being interfered and improve the call quality.

In order to further reduce the clutter interference generated by the power module, when designing the motherboard, set the power supply and GND on different layers, and separate the power supply part from the RF part to reduce their mutual influence.

At the same time, as shown in Figure 6, a coupling circuit is added to the BT-RF pin, the coupling circuit is connected to the antenna, and the output terminal is connected to a filter to achieve circuit matching, so as to reduce the attenuation of the signal during transmission and make the secondary Harmonics are reduced to improve RF transmission efficiency to achieve the best transmission effect.

The PIFA antenna is selected as the antenna, and the PIFA antenna can be coupled with the circuit to improve the RF transmission efficiency and send signals better. At the same time, the Bluetooth output power level is set to class1 level (8dBm), which increases the sensitivity of conventional Bluetooth by 20% (- 80dBm to -90dBm).

The size of the Bluetooth headset mentioned above is shown in Figure 3 and Figure 4. The widest part is 25.2mm×19.7mm×16.3mm, and the narrowest part is 14.5mm×19.7mm×16.3mm; due to the small size, the microphone is far away from the mouth. The relevant digital signal processor is integrated in the CSR8670 for signal processing, as shown in Figure 6, which can realize intelligent recognition of voices from various directions.

Continue as shown in Figure 1, as a preferred embodiment of the first embodiment, the circuit structure 2 of the Bluetooth headset also includes a touch device 25; the touch device 25 is electrically connected to the power supply 24 and the main board 21; the touch device 25 includes a touch panel 252 and Touch switch 251; In order to ensure the overall appearance, an invisible touch area 121 is set on the back cover 12. The invisible touch area mainly adopts a piece of glass that is similar in color to the housing 1 or dark in color to achieve an invisible effect visually. The invisible touch area 121 can control the touch switch 251 provided on the touch panel 252 inside the housing 1 outside the housing 1 .

Among them, as shown in Figure 8, because the touch part adopts the click type, it can generate a high-level signal. When the high-level signal is connected to the PIO pin of the CSR8670, the touch control module of the CSR8670 can realize the corresponding function, for example Answer/hang up calls, display power and adjust volume, etc.

Continue as shown in FIG. 1, as another preferred embodiment of the first embodiment, the circuit structure 2 also includes a bluetooth display light 26, the bluetooth display light 26 is electrically connected to the main board 21, and is powered by a power supply 24. The cover 12 is provided with a through hole 122 for accommodating the bluetooth indicator light 26, and the lamp cap part of the bluetooth indicator light 26 can be extended out of the rear cover 12 through the through hole 122; The connection between the Bluetooth headset and other devices.

In order to achieve the waterproof effect, as shown in Figure 1, a waterproof sound-permeable net 27 is set on the contact surface between the microphone 22 and the loudspeaker 23 and the outside world, the sound can penetrate the waterproof sound-permeable net 27, and water vapor will not enter the microphone 22 and the microphone 22 at the same time. Inside the speaker 23.

As shown in Figure 7, a power protection circuit is also provided on the power board, wherein R16 is a thermistor. When the earphone is being charged, U2 generates heat. When a certain temperature is reached, the resistance of R16 is 0 ohms, realizing circuit conduction. At this time, the NTC pin is at a low level, and U2 is in a closed state, so as to realize the temperature protection of the power supply. At the same time, connect the MODE pin to U1 (that is, CSR8670), and configure the corresponding high level and low level through U1, so that U2 passes the static current to achieve the effect of increasing the use time.

As yet another preferred embodiment of the first embodiment, that is to realize two ears listening to music and talking at the same time, the implementation method is as follows: two bluetooth earphones of the above-mentioned embodiment are required, one is set as the main bluetooth earphone, and the other As a secondary Bluetooth headset, connect the main Bluetooth headset with the user device and the secondary Bluetooth headset respectively; after the connection is completed, the user device generates two audio source signals, which are sent to the primary Bluetooth headset through the Bluetooth protocol, and the primary Bluetooth headset shares one signal to the secondary Bluetooth headset. earphone.

The Bluetooth headset proposed by the present invention has been introduced above, and the method for improving call quality proposed by the present invention will be introduced below.

The method for improving the call quality of the above-mentioned Bluetooth headset is as follows:

Cancel the internal power supply in the audio processing circuit, and use an external power supply to power the audio processing circuit; specifically, as shown in Figure 6, cancel the internal 1.8V and 1.35V power supply of the CSR8670, and use an external power supply, J9 and J7 are not used , J8, J6 are connected with the ground wire. The rest of the power detection pins are connected to the external power supply. Through U5, connect the battery to generate two sets of power supply 1.8V and 1.35V to enable the CSR8670 to work normally; at the same time, separate the power supply part from the RF part on the motherboard layout;

Set the Bluetooth output power from class2 to class1; in general, the Bluetooth output power of non-commercial equipment is set to class2, and the maximum communication distance is 10 meters, while the communication distance of class1 reaches 40-50 meters, but due to the large distance Therefore, the present invention adjusts the transmission power of class1 to 8dBm. At this time, the Bluetooth communication distance is about 20 meters. At the same time, in order to make the connection more stable, the power supply and GND are set on different layers when designing the motherboard. Number, the power part and the RF part are separated to reduce their mutual influence, the connection stability is strong, and the stable Bluetooth communication distance is doubled on the original basis.

As shown in Figure 6, by adding a coupling circuit to the BT-RF pin and adjusting the parameters of the matching network, the second harmonic of the PCB board is reduced to match the characteristic impedance of the PIFA antenna and increase the RF transmission efficiency. The external 1.8V and 1.35V power supply is used to reduce the influence of power supply on RF, and at the same time avoid the influence of noise generated by internal power supply on signal transmission, so that the output power of RF is increased, and the sensitivity of Bluetooth is increased by 20%.

And because the touch device circuit uses a click-type touch panel, it can generate a high-level signal when it is used. When the high-level signal is connected to the PIO pin of the CSR8670, the touch control module of the CSR8670 shown in Figure 8 can realize the corresponding Function.

In order to stabilize the power supply, as shown in Figure 7, a power supply protection circuit is also set on the power supply board, wherein R16 is a thermistor. When the earphone is charging, U2 generates heat. When a certain temperature is reached, the resistance of R16 is 0 ohms , to realize the conduction of the circuit, at this time, the NTC pin is at low level, and U2 is in the off state, so as to realize the temperature protection of the power supply. At the same time, connect the MODE pin to U1 (that is, CSR8670), and configure the corresponding high level and low level through U1, so that U2 passes the static current to achieve the effect of increasing the use time.

The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, without departing from the principle and spirit of the present invention, various changes, modifications, substitutions and modifications to these embodiments still fall within the protection scope of the present invention.

Claims (8)

1. A bluetooth headset, characterized in that it comprises: a housing and a circuit structure, wherein the housing includes a front cover and a back cover that is embedded with the front cover; the circuit structure is accommodated in the front cover and the internal space formed by closing the back cover; the circuit structure includes a main board, an antenna, a power supply, a speaker and a microphone; the main board is electrically connected to the antenna, the loudspeaker and the microphone respectively; the power supply is respectively Power supply for the main board, the antenna, the loudspeaker and the microphone; the main board is provided with an audio processing circuit, a clock oscillator, a filter and a coupling circuit. 2. The bluetooth earphone according to claim 1, characterized in that: the circuit structure also includes a touch device; the touch device is electrically connected to the power supply and the main board; the touch device includes a touch panel and a touch switch; an invisible touch area is arranged on the rear cover. 3. The bluetooth earphone according to claim 1 or 2, characterized in that: the circuit structure also includes a bluetooth display light, the bluetooth display light is electrically connected to the power supply and the main board, and on the back cover A through hole for accommodating the bluetooth display light is provided. 4. The bluetooth earphone according to claim 1 or 2, characterized in that: both the speaker and the microphone are provided with waterproof and sound-permeable nets. 5. The bluetooth earphone according to claim 1, characterized in that: the power supply includes a power board, a battery and a charging interface arranged on the power board; the battery is installed on a battery holder, and the battery holder connects the The battery is fixed inside the housing together with the power board. 6. The Bluetooth headset according to claim 1, wherein the speaker comprises one of a moving iron speaker, a moving coil speaker, an isomagnetic speaker, an electrostatic speaker and an electret speaker. 7. The Bluetooth headset according to claim 1, wherein the audio processing circuit comprises one of CSR8670, CSR8645 and CSR8675. 8. The bluetooth headset according to claim 1, wherein the antenna comprises a PIFA antenna.