Integrated sub-assembly for wearable audio device
An audio headset sub-assembly ( 600, 700, 900, 1000, 1200, 1300, 1500 ) providing the operative functionality for true wireless headphones/headset ( 100 ) includes circuitry operative to effect wireless communication and audio signal processing, and a battery ( 212 ). These circuits and battery ( 212 ) are contained in a sealed enclosure ( 610, 710, 1210, 1310 ). In one embodiment, the sub-assembly ( 600, 700, 900, 1000, 1200, 1300, 1500 ) includes all electronic components for wireless communications and audio signal processing, and a battery ( 212 ), but does not include a speaker. A microphone ( 240 ) may be part of the sub-assembly ( 600, 700, 900, 1000, 1200, 1300, 1500 ) or may be external. In another embodiment, a speaker ( 230 ) is part of the sub-assembly ( 600, 700, 900, 1000, 1200, 1300, 1500 ) as well. The sub-assembly ( 600, 700, 900, 1000, 1200, 1300, 1500 ) may include several cavities ( 1254, 1252 ) and vents ( 1264, 1262 ) before and behind the speaker ( 230 ) for optimal acoustic performance. The sub-assembly ( 600, 700, 900, 1000, 1200, 1300, 1500 ), and any necessary external audio components, can be inserted in an external housing ( 104 ) forming the visual product appearance and the anthropometric comfort and fit design of a true wireless headphone or headset ( 100 ).
1. An audio headset sub-assembly, comprising a battery and a folded electronics construction, comprising two or more rigid circuit boards connected by at least one flexible circuit board and folded around the battery, placed together in a contained enclosure separate from a housing that contains it, the folded electronics construction holding components implementing functionality including:
an antenna;
a radio transceiver;
a microcontroller;
an audio codec;
a power management unit; and
a connector coupled to one of the circuit boards;
wherein the contained enclosure is characterized by:
a first cavity including the battery and circuit boards, the cavity being completely sealed to repel environmental substances;
air space to allow for the battery to swell in the event of malfunction; and
a hole in the enclosure wherein the connector is sealed.
2. The sub-assembly of claim 1 further characterized by at least one microphone connected to the audio codec for voice pick-up.
3. The sub-assembly of claim 1 further characterized by a receive coil to support wireless charging.
4. The sub-assembly of claim 1 wherein the contained enclosure is built first in a molding process and the battery and folded board containing electronic components are inserted in the enclosure afterwards, after which the enclosure is sealed.
5. The sub-assembly of claim 1 wherein the contained enclosure is built around the battery and folded board containing electronic components using a 3D printing or molding process.
6. The sub-assembly of claim 1 wherein the contained enclosure is further characterized by:
a second cavity including a speaker, the second cavity comprising a first air space forming a back acoustic chamber at the back end of the speaker and a second air space forming a front acoustic chamber at the front end of the speaker and
a venting hole in air flow relationship with the back acoustic chamber.
7. The sub-assembly of claim 6 further characterized by one or more venting holes in air flow relationship with the front acoustic chamber.
8. The sub-assembly of claim 6 further characterized by at least one noise cancellation microphone being operative to measure air pressure in the front acoustic chamber.
9. The sub-assembly of claim 8 , further characterized by an acoustic passage connecting the noise cancellation microphone with the front acoustic chamber.
10. The sub-assembly of claim 8 , wherein the signal of the noise cancellation microphone is used for active noise cancellation.
11. The sub-assembly of claim 6 wherein the first cavity is acoustically separated from the second cavity.
12. The sub-assembly of claim 1 wherein the folded electronics construction comprises:
the antenna formed on a first side of a first printed circuit board, PCB;
the microcontroller mounted on a first side of a second PCB;
a first flexible PCB connecting the first and second PCBs such that the first sides of PCBs face the same direction when all circuit boards are coplanar;
wherein the first flexible PCB is bent such that the first PCB overlays and is spaced apart from the second PCB, wherein the first sides of the first and second PCBs face away from each other.
13. The sub-assembly of claim 12 wherein at least one of the first and second PCBs includes a ground plane, and wherein the ground plane is interposed between the first side of the first PCB and the first side of the second PCB, and is operative to provide RF shielding between the antenna and the microcontroller.
14. The sub-assembly of claim 12 wherein the battery is disposed between the first and second PCBs.
15. The sub-assembly of claim 14 further characterized by a speaker connected to the first side of the second PCB.
16. The sub-assembly of claim 12 wherein the folded electronics construction further comprises:
a third PCB;
a second flexible PCB connecting the second and third PCBs such that the first sides of the PCBs face the same direction when all circuit boards are coplanar;
wherein the second flexible PCB is bent such that the third PCB underlays and is spaced apart from the second PCB, wherein the first sides of the second and third PCBs face towards each other; and
the battery is disposed between the second and third PCBs.
17. The sub-assembly of claim 16 wherein the connector is mounted on a second side of the third PCB.
18. A method of manufacturing an audio headset sub-assembly characterized by:
providing an electronics construction comprising an antenna formed on a first side of a first rigid printed circuit board, PCB, a microcontroller mounted on a first side of a second PCB, and a first flexible PCB connecting the first and second PCBs such that the first sides of PCBs face the same direction when all circuit boards are coplanar;
folding the electronics construction by bending the first flexible PCB such that the first PCB overlays and is spaced apart from the second PCB, wherein the first sides of the first and second PCBs face away from each other; and
encapsulating the folded electronics construction and a battery in a first cavity of a contained enclosure that is completely sealed to repel environmental substances and that is separate from a housing that contain the contained enclosure.
19. The method of claim 18 further comprising disposing the battery between the first and second PCBs prior to the encapsulating step.
20. The method of claim 18 further characterized by:
providing a speaker operatively connected to the electronics construction; and
encapsulating the speaker in a second cavity comprising a first air space forming a back acoustic chamber at the back end of the speaker and a second air space forming a front acoustic chamber at the front end of the speaker; and
wherein the back acoustic chamber includes a venting hole in air flow relationship with exterior of the enclosure.
21. The method of claim 18 wherein encapsulating the folded electronics construction and the battery in the first cavity of the contained enclosure comprises:
providing a body of the enclosure;
placing the folded electronics construction and the battery in the body of the enclosure; and
sealing the body of the enclosure with a lid.
22. The method of claim 21 wherein providing a body of the contained enclosure comprises forming the enclosure in a molding process.
23. The method of claim 18 wherein encapsulating the folded electronics construction and the battery in the first cavity of the contained enclosure comprises building the contained enclosure around the folded electronics construction and the battery using a 3D printing or molding process.
24. The method of claim 23 further characterized by:
providing a microphone operatively connected to the electronics construction; and
forming one or more air passages in the contained enclosure connecting the exterior of the enclosure in air flow relationship to the microphone.
25. The method of claim 23 further characterized by:
providing at least one noise cancellation microphone operatively connected to the electronics construction and operative to measure air pressure in the front acoustic chamber; and
forming an acoustic passage connecting the noise cancellation microphone with the front acoustic chamber;
wherein the signal of the noise cancellation microphone is used for active noise cancellation.