The present invention relates generally to electronics devices, such as electronics devices for voice communications and music listening. More particularly, the invention relates to a sub-assembly for wireless audio devices wearable on the body.
The use of audio devices, such as headsets and headphones, wirelessly connected to host devices like smartphones, laptops, and tablets, is becoming increasingly popular. Whereas consumers used to be tethered to their electronic devices with wired headsets, wireless headsets are gaining more traction due to the improved user experience, providing the user more freedom of movement and ease of use. Wireless audio devices allow the user to enjoy untethered music entertainment and voice communications. Further momentum for wireless headsets has been gained by certain smartphone manufacturers abandoning the implementation of the 3.5 mm audio jack in the smartphone for wired connections, and promoting voice communications and music listening wirelessly, for example by using Bluetooth® technology.
Headsets and headphones come in many forms and features. Over-the-ear headsets allow immersive listening to high quality sound. In-ear headsets (ear buds placed in the ear canal or in the concha) are more flexible and provide less presence to the user. Most of these in-ear headsets and headphones consist of a left and right ear bud connected with a cable or neckband. More recent designs offer a separate left and right ear bud with no connection between the buds. Examples of these so-called True Wireless headsets are the Apple AirPods and the Samsung IconX.
For ease of use and wearing comfort, miniaturization is key for in-ear headsets. Yet product miniaturization faces many challenges in robustness and reproducible manufacturing. For very small device, the placement of components becomes very important for the wireless performance since the antenna effectiveness is impacted by its surroundings. Small variations in separation between the antenna and conductive elements in the surroundings may give rise to large variations in the RF performance of the radio. Variations not only occur in the design process but also in the manufacturing process, especially if the volumes of these products exceed millions per month. A good user experience for all of these users becomes more and more important.
Furthermore, the performance of these small headsets is plagued by environmental substances like (salty) water, sweat, dust, body lotion, sunburn oil, and so on. These substances may affect the proper operation of the electronics inside the audio device and may erode conductive lines and contacts, for example at the battery, with the danger of short-circuiting. Coating (e.g., parylene or nano coatings) complicates the manufacturing process and does not always give sufficient protection. In addition, new regulations regarding safety (see for example IEC 62368-1, Safety requirements for audio/video, information and communication technology equipment, 2014) requires product designers to build in safeguards against malfunctioning components like the battery, in order to prevent fire, injury, or other harmful effects when using the product.
For each new product design, the developers face these challenges again and again. Conflicting requirements between the electronic designers (dealing with performance and safety), visual designers (dealing with look and feel, ergonomics like user interface, comfort, and fit, and dealing with color/material/finish, or CMF), and manufacturing (dealing with yield, reproducibility, tolerances), frequently delay the product launch, affect the time-to-market, and eventually the success of the product on the market.
It is therefore the intention of the inventors to introduce a new method and concept that allows product designers to make use of pre-fabricated, miniaturized, sealed sub-assemblies that have predictable performance and are highly reproducible.
The Background section of this document is provided to place embodiments of the present invention in technological and operational context to assist those of skill in the art in understanding their scope and utility. Unless explicitly identified as such, no statement herein is admitted being prior art merely by its inclusion in the Background section.
The following presents a simplified summary of the disclosure in order to provide a basic understanding to those of skill in the art. This summary is not an extensive overview of the disclosure and is not intended to identify key/critical elements of embodiments of the invention or to delineate the scope of the invention. The sole purpose of this summary is to present some concepts disclosed herein in a simplified form as a prelude to the more detailed description that is presented later.
According to one or more embodiments described and claimed herein, a sub-assembly includes circuitry and a battery operative to effect wireless communication and audio signal processing. These circuits and battery are contained in a sealed enclosure. The sub-assembly provides the fundamental functionality for true wireless headphones/headset, and may be designed into a variety of wireless audio devices, having varying degrees of functionality and sophistication.
In one embodiment, the sub-assembly includes all electronic components for wireless communications and audio signal processing, and a battery. A speaker is not part of the sub-assembly. A microphone may be part of the sub-assembly or may be external. The audio components are connected to the sub-assembly via a connector to provide a fully functional wireless audio device. Audio components and the sub-assembly can subsequently be inserted in an external housing forming the visual product appearance and the anthropometric comfort and fit design.
In another embodiment, a speaker is part of the sub-assembly as well. The sub-assembly includes several cavities and vents before and behind the speaker for optimal acoustic performance. This self-contained sub-assembly can be inserted in an external housing forming the visual product appearance and the anthropometric comfort and fit design.
One embodiment relates to an audio headset sub-assembly comprising a battery and a folded electronics construction, including flexible parts and folded around the battery, placed together in a contained enclosure, 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 the board. The contained enclosure is characterized by a first cavity including the battery and the folded board, 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.
Another embodiment relates to a method of manufacturing an audio headset sub-assembly. An electronics construction is provided. The electronics construction comprises an antenna formed on a first side of a first rigid PCB, a microcontroller mounted on a first side of a second rigid PCB, and a first flexible PCB connecting the first and second rigid PCBs such that the first sides of rigid PCBs face the same direction when all circuit boards are coplanar. The electronics construction is folded by bending the first flexible PCB such that the first rigid PCB overlays and is spaced apart from the second rigid PCB, wherein the first sides of the first and second rigid PCBs face away from each other. The folded electronics construction and a battery are encapsulated in an enclosure that is completely sealed to repel environmental substances.
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, showing several embodiments of the invention. However, this invention should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
For simplicity and illustrative purposes, the present invention is described by referring mainly to exemplary embodiments thereof. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be readily apparent to one of ordinary skill in the art that the present invention may be practiced without limitation to these specific details. In this description, well known methods and structures have not been described in detail so as not to unnecessarily obscure the present invention.
The inventors have recognized that for stable design and manufacturing process with predictable outcome, for miniaturized product design it is advantageous to split the product into an interior 109 as shown in
A high-level functional schematic diagram of the electrical and acoustical components inside the interior 109 is shown in
The digital messages are then transferred to a microcontroller 206 for further processing. Signals may then be processed in an audio codec 208 where they are converted to the analog domain. The analog signal can then drive a speaker 230, so that the user can experience music or voice communications. In the opposite direction, a microphone 240 may be present to pick-up the voice of the user. This voice signal is then digitized in audio codec 208 and via the microcontroller 206. The radio transceiver 204 then places it on a 2.4 GHz radio carrier to be transmitted by antenna 201. For more advanced audio processing (multi-MIC beam forming, active noise cancellation, etcetera), a Digital Signal Processor (DSP) 216 may be added.
The electronic circuitry must be powered by a stable power source. Rechargeable battery 212 provides energy to the entire system. Safety circuitry 213 monitors the battery for malfunctioning, and can shut off the power supply if necessary. Power management unit (PMU) 210 conditions power from the battery to provide stable, interference-free voltages and currents to the various electronic components. PMU 210 also serves as a charge controller when the battery is (re-)charged via an external energy source that is entered via connector 250. For the user to operate the product, a user interface (UI) 214 is present (e.g., buttons, touch, or other controls), which signals are fed into the microcontroller 206. Sensors 218 may be added to provide more features to the product. Functional components in diagram 200 have been shown as separate entities. However, it will be readily apparent to one of ordinary skill in the art that certain functional components may be integrated onto the same silicon chip (integrated circuit, or IC). For example, radio transceiver 204 and microcontroller 206 can be part of the same IC. In some embodiments, audio codec 208 and/or PMU 210 can also be part of this IC.
To provide connectivity, the components are placed on a carrier or board that includes conductive lines connecting the different components. This board can be a rigid Printed Circuit Board (PCB) with several layers, i.e., alternatively isolating and (patterned) conductive layers. Advanced PCBs may also be flexible, and can also be multi-layered. It is also possible to make a combination of flexible and rigid PCBs, so-called flex-rigid PCBs. Using (partly) flexible PCBs allows for further miniaturization because of the freedom to fold and wrap the board in the proper product size.
A physical representation of the components and schematics shown in
Antenna board 310 is on the product side most protruding from the ear. This part will include the antenna 201 and the UI function 214, for easy user access. The antenna 201 is formed by a metal pattern in one of the layers on or near the first surface of board 310. For the antenna efficacy, it is important that other conductive elements are at least a minimum distance away (including the human body, the presence of which causes attenuation of the antenna gain). Therefore, there is a minimum air gap 305 between the antenna board 310 and components board 330. Also, the UI function 214, also on the first surface of board 310, is spaced apart from the antenna 201, as best seen in
Radio transceiver 204, microcontroller 206, and PMU 210 are placed on the first side of the components board 330 to maximize the spacing away from antenna 201 when the boards are folded as depicted in
The folded board construction, with battery 212 and all electronics components depicted in
In
Enclosure 610 with lid 620, or complete enclosure 710, with the folded construction 300 inside forms a sub-assembly 600, 700 around which a wireless audio product can be made. An example of such a wireless audio product 800 is shown in
In the embodiment shown in
It will be readily apparent to one of ordinary skill in the art that a microphone can also be included in the sub-assembly 700. In this case (not shown), a hole is formed in enclosure 710 and proper sealing must be applied to keep the enclosure hermetically sealed. In another embodiment, the microphone is not placed on a board, but is connected via a wire, preferably using a flex PCB, to the board. This allows more flexibility of placement of the microphone, for example at the side of the sub-assembly, see
When the sub-assembly 600 is embedded in the final product, the external housing must have the proper holes for the air waves to reach the microphone. For example, the embodiment shown in
In another embodiment of the sub-assembly, the speaker 230 is integrated as well. This especially relevant for so-called “open speaker” constructions where the speaker is not pushed into the ear canal of the user. These open speakers usually have a larger diameter. The side view of a folded construction, according to one embodiment, to fit the electronic components is shown in
The folded board construction with battery 212, speaker 230, and all electronic components depicted in
The bottom enclosure part 1211b consists of two cavities 1252 and 1254 which form the back and front acoustic chambers, respectively. Speaker 230 is placed in the bottom enclosure part 1211b such that there is no air flow from chamber 1252 to chamber 1254 and vice versa, i.e., they are acoustically separated by (plastic) sealings 1257a and 1257b. The speaker is placed in the bottom enclosure part 1211b from above before folded construction boards 310/330 are placed in cavity 1250 and before lid 1220 is placed. After speaker 230 is placed in position, lid 1222 is closed to acoustically separate the cavity 1250 from the cavity 1252. A hole in lid 1222 is needed to fit connector 1110 connecting the speaker 230 to the component board 330. Additional (plastic) sealing 1255 may be added to prevent any air leakage between cavity 1250 and cavity 1252.
To control the air flow in the back acoustic chamber 1252, a vent 1262 is present whose air flow can be regulated with damper 1268a. Damper 1268a has a certain air permeability that more or less hinders air from flowing inside and outside the back acoustic chamber 1252. Furthermore, the position of the damper 1268a determines the effective acoustic size of the back acoustic chamber 1252. In the same manner, to control the air flow in the front acoustic chamber 1254, a vent 1264 is present whose air flow can be regulated with damper 1268b. Damper 1268b has a certain air permeability that more or less hinders air from flowing inside and outside the front acoustic chamber 1254. Furthermore, the position of the damper 1268b determines the effective acoustic size of the front acoustic chamber 1252. Finally, nozzle 1270 is the acoustic load and guides the air flow to the user's ear.
Speaker 230, front and back acoustic chambers 1254 and 1252, vents 1264 and 1262, dampers 1268b and a, and nozzle 1270 together form an acoustic system. The frequency response of this acoustic system can be determined by the size of the acoustic cavities, the diameter of the nozzle, the diameter of the vents, and by the amount of air that can flow in and out of the vents per unit time. The latter depends on the diameter of the vents, the choice of material (air permeability characteristics) of the dampers, and the position of the dampers inside the vents. To a certain extent, acoustic fine tuning can be obtained by the positioning of dampers inside the vents as this will change the acoustic size of the chambers. The nozzle 1270 may include a protection means 1269 to prevent dust and grease from entering the front acoustic chamber 1254. This protection means should dampen the air flow into the user's ear as little as possible. Yet, it may have some influence on the final frequency response of the acoustic system.
In
Sub-assemblies 1200 and 1300 can readily be embedded in a wireless audio product. An example of such a wireless audio product is shown in
In
Microphone 240c can be added to measure the pressure in the front acoustic chamber 1254. An internal acoustic passage, such as tube 1530, connects the bottom acoustic chamber 1254 to the microphone 240c. Optionally, damper means 1540 may be added to control the air flow to the microphone 240c. Microphone 240c can be used for acoustic tuning, but can also be used for active noise cancelling techniques. The sound measured in the front chamber by microphone 240c is converted into an electrical signal and fed back to the audio codec, where it is compared to the original audio signal (e.g., music). Any differences are electronically minimized and compensated for.
To the sub-assemblies described above, several sensors may be added. Sensor can be added user interface (UI), e.g., to control functions like volume up/volume down, next track, start/stop, on/off. Other sensing functions may be in-ear detection, detecting ambient conditions, and human body functions like heart rate, oxygen saturation, temperature, etc.
In
Embodiments of the present invention present numerous advantages over the prior art. The embodiments provide a fully functional, self-contained audio system that is easily designed into a variety of “true wireless” headphones. Embodiments without a microphone are optimized to music playback applications; embodiments with an integrated microphone(s) are appropriate for telephone or radio headsets. The designs are compact, featuring a novel combination of hard and flexible PBC boards that are “foldable” to optimize volumetric size and placement. Component configurations are optimized to minimize interference between processing circuitry and RF circuits. The modules are hermetically sealed for durability and long life, and comply with safety regulation such as malfunctioning battery expansion. Some embodiments with integrated speakers feature advanced audio tuning features and capabilities, such as separate and ported acoustic chambers, and an internal microphone for feedback applications such as noise cancellation.
The present invention may, of course, be constructed in other ways than those specifically set forth herein without departing from essential characteristics of the invention. The present embodiments are to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.
This application claims the benefit of U.S. Provisional Patent Application No. 62/714,788, filed Aug. 6, 2018, which is hereby incorporated by reference in its entirety.
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PCT/EP2019/070993 | 8/5/2019 | WO |
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WO2020/030576 | 2/13/2020 | WO | A |
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