WO2011114188A1

WO2011114188A1 - An apparatus and a method for waterproofing a transducer

Info

Publication number: WO2011114188A1
Application number: PCT/IB2010/051157
Authority: WO
Inventors: Esa-Sakari Maatta; John Etheridge; Tim Porter; James Moyle
Original assignee: Nokia Corporation
Priority date: 2010-03-17
Filing date: 2010-03-17
Publication date: 2011-09-22

Abstract

An apparatus comprising: an acoustic window configured to provide an interface between an acoustic channel and an environment external to the apparatus; a seal portion configured to close the acoustic channel when the seal portion experiences pressure greater than a predefined pressure from the environment external to the apparatus; and a flexible connection configured to permit the seal portion to move relative to the acoustic channel.

Description

An apparatus and a method for waterproofing a transducer

The present invention relates to an apparatus. The invention further relates to, but is not limited to, an apparatus for use in mobile devices.

Many portable devices, for example mobile telephones, contain a number of acoustic transducers, such as microphones, earpieces and speakers. Such transducers are key components in mobile phone audio/acoustic design. Generally, there will be one or more sound channels or back cavities associated with each acoustic transducer. Such sound channels can ensure a certain frequency response is obtained for the transducer, and must be carefully designed as part of the mechanical configuration of the device hardware. Small changes in the size and configuration of the sound channels or cavities can have a large effect on the acoustic properties of the combined transducer/sound channel.

This issue is particularly troublesome when producing submersible, waterproof equipment. Although many mobile phones and portable apparatus can be said to be splash-proof or rainproof, they typically will fail to be truly submersible. In some portable equipment, a acoustic porous by waterproof membrane material (such as Gore-tex) can be placed in over the acoustic port and in front of the speaker. These waterproof thin membranes although being water resistant and sold as being waterproof in phones and cameras are not typically fully waterproof and pressures experienced in water depth of over one meter typically cause leakage through the membrane and can therefore damage the sensitive electronic and mechanical elements in the device casing.

One such way to make the equipment truly submersible is to design such equipment for underwater use by sealing all ports and doors. However this approach does not produce a good quality acoustic performance device. In order to produce good quality acoustic reproduction or capture of audio signals, a relatively free movement of air between a transducer (for example a loudspeaker) to the ambient external side of the equipment is required. This applies to both loudspeaker, earpiece and microphone design. Thus by ruggedizing equipment with a solid material seal to block the pathway of the water, produces a significant deterioration in both audio capture and reproduction as there is no acoustic path. Thus it would be beneficial to be able to adapt the mechanical hardware design of such apparatus to be able to produce a seal when pressures are high enough to overcome a thin membrane seal area yet still maintain a fairly or relatively free air acoustic pathway as when the device is not submerged. It is an aim of at least some embodiments of the invention to address one or more of these problems.

According to a first aspect of the invention there is provided an apparatus comprising: an acoustic window configured to provide an interface between an acoustic channel and an environment external to the apparatus; a seal portion configured to close the acoustic channel when the seal portion experiences pressure greater than a predefined pressure from the environment external to the apparatus; and a flexible connection configured to permit the seal portion to move relative to the acoustic channel.

The flexible connection may be configured to resiliently locate the seal portion away from a seal surface when the seal portion experiences pressure less than or equal the predefined pressure from the environment external to the apparatus. The acoustic window may comprise an acoustically transparent membrane.

The apparatus may further comprise a transducer wherein the acoustic channel is configured to provide an acoustic pathway between the transducer and acoustic window. The seal portion may be configured to cover and seal an acoustic port to close the acoustic channel, wherein the acoustic window is located adjacent the acoustic port. The seal portion may be configured to close the acoustic channel by co-operating with a further surface located over and at least partially separated from an acoustic port, wherein the acoustic window located over the further surface.

The seal portion may comprise an elastic bag, wherein the elastic bag comprises: a first window on at least one surface of the elastic bag configured to be the acoustic window, and a second window located adjacent to and on a surface other than the at least one surface, the second window co-operating with an acoustic port of at least one transducer. The seal portion may comprise a plug configured to co-operate with a surface of an acoustic port to close the acoustic channel when the seal portion experiences pressure greater than a predefined pressure from the environment external to the apparatus. The seal portion may be a tubular member configured to constrict and close the acoustic channel when the seal portion experiences pressure greater than a predefined pressure from the environment external to the apparatus.

The acoustic window may comprise a plurality of acoustic window parts, wherein the seal portion may comprise a plurality of seal portion parts, and the acoustic channel may comprise a plurality of acoustic pathways wherein the plurality of seal portion parts may be configured to seal the acoustic pathways.

The acoustic window may be configured to provide protection from liquid or particle ingress to the apparatus less than a second predefined pressure external to the apparatus, wherein the first predefined pressure is less than the second predefined pressure. The apparatus may further comprise a second seal portion connected to the flexible portion and configured to provide a second seal to the apparatus to define the acoustic channel.

The pressure from the environment external to the apparatus may be liquid or water pressure.

The transducer may be at least one of a microphone transducer, and earpiece transducer, a loudspeaker transducer, an integrated hands free loudspeaker transducer, and a headphone transducer.

According to a second aspect of the invention there is provided a method comprising: providing with an acoustic window an interface between an acoustic channel and an environment external to an apparatus; closing with a seal the acoustic channel when the seal experiences pressure greater than a predefined pressure from the environment external to the apparatus; and permitting the seal portion to move relative to the acoustic channel with a flexible connection. The method may further comprise locating the seal portion away from a seal surface with the flexible connection when the seal experiences pressure less than or equal the predefined pressure from the environment external to the apparatus. An electronic device may comprise the apparatus as described above. For better understanding of the present invention, reference will now be made by way of example to the accompanying drawings in which:

Figure 1 shows schematically an electronic device employing embodiments of the invention;

Figure 2 shows schematically an isometric view of an acoustic valve according to some embodiments of the application; Figure 3 shows a sectioned view of the acoustic valve shown in Figure 2 showing the open and closed position of the valve;

Figure 4 shows a sectioned view of an adjacent window acoustic valve according to some embodiments of the application;

Figure 5 shows a sectioned view of an acoustic valve with a symmetrical acoustic window according to some embodiments of the application;

Figure 6 shows sectioned views of open and closed valve operation of an elastic bag acoustic valve according to some embodiments of the application;

Figure 7 shows schematic views of an expandable bag acoustic valve according to some embodiments of the application;

Figure 8 shows a schematic view of a plug acoustic valve according to some embodiments of the application;

Figure 9 shows a schematic view of a tube acoustic valve according to some embodiments of the application; and

Figure 10 shows a schematic view of an acoustic window pattern acoustic valve according to some embodiments of the application.

The following describes in further detail suitable apparatus and possible mechanisms for the provision of transducers having changeable acoustic properties. In this regard reference is first made to Figure 1 which shows a schematic block diagram of an exemplary apparatus or electronic device 10, which may incorporate transducers with acoustic valves according to some embodiments.

The electronic device 10 may for example be a mobile terminal or user equipment of a wireless communication system.

The electronic device 10 comprises a microphone 1 1 , which is linked via an analogue-to-digital converter (ADC) 14 to a processor 21. The processor 21 is further linked via a digital-to-analogue (DAC) converter 32 to loudspeakers 33. The processor 21 is further linked to a transceiver (TX RX) 13, to a user interface (Ul) 15 and to a memory 22. The processor 21 may be configured to execute various program codes. The implemented program codes may comprise encoding code routines. The implemented program codes 23 may further comprise an audio decoding code. The implemented program codes 23 may be stored for example in the memory 22 for retrieval by the processor 21 whenever needed. The memory 22 may further provide a section 24 for storing data.

The user interface 15 may enable a user to input commands to the electronic device 10, for example via a keypad, and/or to obtain information from the electronic device 10, for example via a display. The transceiver 13 enables a communication with other electronic devices, for example via a wireless communication network. The transceiver 13 may in some embodiments of the invention be configured to communicate to other electronic devices by a wired connection.

It is to be understood again that the structure of the electronic device 10 could be supplemented and varied in many ways.

A user of the electronic device 10 may use the microphone 1 1 for inputting speech, or other sound signal, that is to be transmitted to some other electronic device or that is to be stored in the data section 24 of the memory 22. A corresponding application has been activated to this end by the user via the user interface 15. This application, which may be run by the processor 21 , causes the processor 21 to execute the encoding code stored in the memory 22.

The analogue-to-digital converter 14 may convert the input analogue audio signal into a digital audio signal and provides the digital audio signal to the processor 21 .

The processor 21 may then process the digital audio signal.

The resulting bit stream is provided to the transceiver 13 for transmission to another electronic device. Alternatively, the coded data could be stored in the data section 24 of the memory 22, for instance for a later transmission or for a later presentation by the same electronic device 10.

The electronic device 10 may also receive a bit stream with correspondingly encoded data from another electronic device via the transceiver 13. In this case, the processor 21 may execute the decoding program code stored in the memory 22. The processor 21 may therefore decode the received data, and provide the decoded data to the digital-to-analogue converter 32. The digital-to-analogue converter 32 may convert the digital decoded data into analogue audio data and outputs the analogue signal to the loudspeakers 33. Execution of the decoding program code could be triggered as well by an application that has been called by the user via the user interface 15.

In some embodiments the loudspeakers 33 may be supplemented with or replaced by a headphone set which may communicate to the electronic device 10 or apparatus wirelessly, for example by a Bluetooth profile to communicate via the transceiver 13, or using a conventional wired connection.

Some embodiments allow the hardware integration of the transducers, such as the microphone 1 1 or the speaker 33, to be rendered submersible yet maintain a good acoustic capability.

Thus in embodiments of the application a valve may be located over the transducer arrangement which is capable of shutting the acoustic channel or port when the valve experiences an external pressure provided for example when the apparatus is at a specific depth under water, but provides good acoustic pathways when the apparatus is used (in typical non-submerged state).

The valve as described hereafter can be considered to comprise three components. Firstly the valve comprises an acoustically transparent window portion. The acoustically transparent window portion is a portion within the valve which permits sound to pass through yet is waterproof or at least splash or rainproof to some extent. For example in some embodiments the acoustically transparent window or acoustic window can be manufactured from a material membrane such as Gore-tex. The valve furthermore comprises a seal area. The seal area is configured to shut the acoustic channel water tight after a specific predetermined pressure is exerted upon the valve. In some embodiments as described hereafter as the device is sunk deeper, the water pressure shuts the valve tighter to achieve an even tighter seal. In some embodiments the seal area can be manufactured from any suitable waterproof material such as rubber, pvc, synthetic rubber such as neoprene, silicone rubber and thermo-plastic polyurethanes (TPU) for injection moulded forms. The seal area in embodiments of the invention are configured to overlie the acoustic port and thus when placed over the acoustic port form a seal or be configured to produce a seal by co-operating with a part of the apparatus housing to form the seal.

Furthermore the valve comprises a bellows section. The bellows section comprises an elastic section of the valve which permits the seal portions to move relative to the acoustic port and therefore shut the acoustic channel or acoustic channels.

As described above and will be described in further detail hereafter as the device is submerged the water pressure on the valve increases. Since the acoustic window is waterproof, water should not penetrate into the device in low or no pressure water ingress or liquid presentation (such as the device falling into a shallow puddle, rain, or being splashed). However at depths with corresponding pressures where the material of the acoustic window membrane could fail, and let water through, the water pressure and the seal seals the acoustic channel. The pressure at which the valve closes can be any suitable value and need not be close to the acoustic window membrane value in some embodiments in order to provide a sufficient safety margin in manufacturing faults of the acoustic window membrane. Furthermore as shown in the following embodiments the shutter valve can in some embodiments locate the seal portion and acoustic window area adjacent to each other in order to provide an acoustic pathway with relatively low acoustic impedance.

The sealing action at low and intermediate water pressures as shown in the following embodiments can be further improved by the use of a further acoustic membrane over the sound or acoustic port as well as in the valve. This further acoustic membrane is for example shown in Figure 4 by the membrane 351.

With regards to Figure 2 an isometric view of an acoustic valve according to some embodiments of the application is shown. The acoustic valve assembly 100 can be any acoustic transducer implementation within a suitable device. For example the transducer installation may be an earpiece, integrated hands-free transducer, microphone transducer, or headphone transducer configuration.

The transducer installation 100 comprises the transducer or acoustics component 101 which is located within the apparatus 10. As shown in Figure 2 the apparatus 10 shows a device housing inner portion 103 and outer portion 104. The installation further comprises an acoustic port or sound port passing through both the inner portion 103 and outer portion 104 and providing an acoustic pathway through the casing for the transducer 101 . The sound port, a hole through the inner and outer portions in some embodiments can be physically protected by a protective barrier 106. The protective barrier 106 in some embodiments can be located on supports 105 and located over the sound port off the surface of the housing whereby the gaps between supports 105 provide the acoustic pathway between the acoustic port and the housing.

The transducer installation in such embodiments further comprises an acoustic valve 107 with an anchor portion attached to the outer portion of the housing 104 via a glue or adhesive layer 108. In Figure 2 the anchor portion of the acoustic valve comprises an annulus of material with a flat cross-sectional surface configured to be glued and form a seal with the outer surface of the housing. However it would be appreciated that the anchor portion can be any suitable shape providing it is sufficiently larger than the acoustic port in order to form an outer or fixed seal with the housing. The acoustic valve further comprises a bellows portion 1 13 which is connected to the anchor portion. The bellows portion 1 13 as shown in these embodiments comprises a flexible member, such as a ridged elastic member, configured to be located to the anchor portion at one end and to inner or movable member portion at the other. The bellows portion 1 13 is configured to provide both resiliance and flexibility to permit the inner portion to form the valve seal when pressure is exerted on the valve but maintain the inner portion from forming the valve seal when no such pressure is exerted.

The inner portion 1 14 of the acoustic valve 107 connected to an end of the bellows 1 13 is capable of being moved relative to the anchor portion of the valve 107 and the acoustic port to be able to seal the acoustic port. The inner portion 1 14 thus forms a valve seal with a seal portion or feature 1 1 1. The seal feature for example as shown in Figure 2 shows a annular step profile portion suitable for forming a valve seal against the mechanically protective layer 106 as the inner portion of the valve 1 14 is moved relative to the anchor portion of the seal and in a direction towards the transducer when under pressure from external forces.

The valve inner portion 114 further is configured to have a valve acoustic hole portion. The valve acoustic hole portion is covered by the acoustic window 109. The acoustic window 109 as described previously can be configured to be any suitable waterproof yet acoustically permeable membrane. For example in some embodiments the material may be Gore-tex or similar material. The acoustic window portion 109 can be configured to be glued to the underside of the inner portion 1 14 of the acoustic valve 107 to cover the valve acoustic hole. In the embodiment shown in Figure 2 the thickness of the membrane layer 109 is configured to be less or equal to the depth of the step portion of the seal feature 1 1 1 such that as external pressure is placed upon the valve causing the inner portion 1 14 to move relative to the outer portion or anchor portion 107 then the seal feature forms a waterproof seal against the mechanical protection layer 106 of the casing.

With respect to Figure 3, the acoustic valve shown in Figure 2 is shown in an open and closed state.

With respect to Figure 3 a schematic view cross sectional view of the valve is shown whereby on the left side 201 of the figure shows the valve operating in an open mode. In the open mode the housing 103 is connected to the anchor of the valve 107 forming a fixed seal, the bellow portion 1 13 of the valve is in its normal operation state and suspends the inner portion 1 14 away from the mechanical protection layer 106 thus maintaining an open acoustic pathway. Thus as can be seen in Figure 3, there is an acoustic pathway through the acoustic port, the supports 105, an air gap between the inner portion of the valve 1 14 and the physical protective layer 106, and the acoustic window 109. The term acoustic pathway or acoustic channel describes an acoustic conduit which can between the transducer and the outside or external side of the apparatus. As such the term acoustic pathway or acoustic channel can comprise or effectively pass through an acoustic port, an acoustic cavity, and/or a tuned acoustic chamber.

On the right side 203 of the figure a closed valve is shown when the water pressure, being greater than a predetermined value causes the inner portion of the valve 1 14 to be moved towards the physical protection layer and overcoming the resilience of the bellow portion 1 13 to form a valve seal between the physical protection layer and the inner portion of the valve 1 14 and thus sealing the acoustic pathway and preventing water from entering the device even if water passes through the acoustic window 109.

With respect to Figure 4, a schematic view of a further valve according to some further embodiments is shown. In the configuration shown in Figure 4 there is no physical protection layer of the housing as shown in Figures 2 and 3 but instead the acoustic port or sound port of the device and the acoustic window are located adjacent to each other and a seal portion or feature is located so to be configured to both provide physical protection for the port when the valve is open and also to provide a direct valve seal over the acoustic port. In this example embodiment the device housing 303 comprises an acoustic port 341 suitable for outputting or inputting acoustic energy to or from the acoustic component 301. Furthermore in some embodiments such as the embodiment shown in Figure 4 there is a further membrane layer 351 located over the acoustic port configured to provides further weatherproofing in case of a mechanical failure of the acoustic valve acoustic window 309. The acoustic shutter valve 307 in these embodiments comprises similar anchor portions configured to be located around the acoustic port and forming a fixed seal with the housing, a bellow portion proving a resilient yet flexible member and supporting the inner portion configured to move in response to external pressure towards the housing.

As described above in some embodiments the inner portion of the valve such as shown in Figure 4 does not comprise an acoustic window membrane portion 309 over the acoustic port but has an inner portion with a seal feature area 31 1 directly over the acoustic port and an acoustic window portion 309 adjacent to the acoustic port. In such embodiments the pressure forces the seal area of the inner portion 31 1 down over the acoustic port area to form the valve seal over the acoustic port yet when there is no or low pressure the bellow portion is configured to move the inner portion seal area away from the acoustic port enabling an acoustic pathway between the acoustic port and acoustic window.

With respect to Figure 5, the acoustic valve embodiments differ from the acoustic valve shown in Figures 2 and 3 in that the valve inner portion 414 comprises a central seal portion 41 1 suitable for forming a valve seal over the acoustic port 441 through the device housing 403 and over the acoustics component 401. Surrounding the central seal portion 411 the inner portion 414 comprises at least one acoustic window or window portion 409. With respect to Figure 6, an elastic bag valve configuration according to some embodiments is shown. In such embodiments the anchor and bellows parts of the valve can be seen as being replaced by an elastic bag structure which forms a seal with the housing at a first hole in one of the sides of the elastic bag has an acoustic window, which can be manufactured by affixing an acoustically transparent material over a second hole located on an opposite side but adjacent to the first hole. The elastic bag 507 in such embodiments is designed to have a natural (under conventional air pressure) state which keeps the second side or surface from the first side or surface of the bag and thus generates an acoustic path from the acoustic window 509 on the second surface of the bag 507 to the acoustic component 501 via the hole in the first surface of the bag and the acoustic port in the apparatus housing 503. However when pressure is exerted upon the elastic bag the elastic bag collapses in such a manner that the bag itself forms the seal between the acoustic window 509 and the acoustic component 501 and thus prevents water from passing via the acoustic window 509 to the acoustic component 501.

With respect to Figure 6 both the normal, Open valve' elastic bag 507 and the compressed or 'closed valve' elastic bag 508 are shown.

With respect to Figure 7 a further example valve configuration for 'side firing' acoustic ports is shown according to some embodiments of the application. In these embodiments the valve comprises an expandable box or bag which in normal operation is partially open. In the expandable box is an open face directed to the environment and five closed faces. In at least one of the closed faces is located an acoustic window section which is located near but adjacent the 'side firing' acoustic port. The expandable box is configured so that under normal or low atmospheric pressure the at least one closed face with the acoustic window is located at least partially away from the device housing surface and maintains an acoustic pathway within the acoustic port between the acoustic component 601 and the outside of the valve via the acoustic window 609. However when the valve is placed under pressure the bellows 613 designed as part of the faces of the box expand the shutter valve 607 such that a portion of the valve, the water seal area overlies the acoustic port 641 and forms a seal preventing water entering the acoustic port and reaching the acoustic component 601 . The embodiments shown in Figure 7 are suitable for "side firing" acoustic ports whereby the bottom of the shutter valve closes against the device housing when water or liquid fills the cavity.

With respect to Figure 8 a further valve example according to some embodiments is shown. In this type of valve the acoustic shutter valve 707 comprises a plug configured to be moved within the acoustic port. In the example shown in Figure 8 a frusto-conical plug is shown within an acoustic port with at least a co-operating frustro-conical portion. The plug is as described previously in the other embodiments biased by the bellows towards maintaining an acoustic pathway from the acoustic component 701 and the external surface and via an acoustic window 709. In other words the bellows under normal pressure exerts a force on to the plug to keep the plug away from the acoustic port. The bellows 713 furthermore may comprise the acoustic window portion 709 which when the device is submerged, and pressure is placed against the acoustic window as water enters the gap between the plug and acoustic port, overcomes the natural elastic pressure keeping the plug away from the acoustic plug forms a seal region 7 between the plug and acoustic port. Furthermore once closed any further pressure placed upon the plug from outside further increases the seal.

With respect to Figure 9 a further example of the valve is shown according to some embodiments of the application. In this example the valve 807 comprises a 'sealed tube' which at at least one end comprises an acoustic window 809 (which can comprise any acoustically transparent material as discussed previously), and along the sides comprises a non-acoustically transparent bellows portion 8 3. The sealed tube is physically located in such embodiments within the acoustic port. The acoustic port is further configured in such embodiments to have at least one secondary port which opens open from the outside of the device housing 803 to the tube side portion (or bellows portion 813) of the tube. The valve 807 operates such that the bellows portion 813 in normal usage lines the acoustic port and maintains the acoustic pathway. However as water or other liquid enters via the at least one secondary window, the bellows portion 813 is pushed away from the side and towards the other side sealing the acoustic port and preventing any water entering via the acoustic window 809 through down the acoustic port to the acoustic component 801.

With respect to Figure 10 a multiple acoustic window pattern configuration valve according to some embodiments is shown. In such embodiments rather than large holes with acoustic windows a pattern of acoustic windows 909 are arranged within the water seal layer 911. The water seal layer 91 1 is suspended above or away from the acoustic port or sound hole configuration 951 (for example by the bellows portion of the valve). However under pressure the seal layer 91 1 moves towards the housing part within which the acoustic ports or sound holes 951 are located. A seal layer 91 1 thus forms a seal over and between each of the acoustic ports 951 as none of the acoustic windows 909 of the seal layer 91 1 are directly above any of the sound holes or acoustic port holes 951 .

It would be understood that although the previous examples used a single or few acoustic windows and/or acoustic ports that any suitable pattern of acoustic window and/or acoustic ports can be created.

Thus in at least one embodiments there is an apparatus comprising: an acoustic window configured to provide an interface between an acoustic channel and an environment external to the apparatus; a seal portion configured to close the acoustic channel when the seal portion experiences pressure greater than a predefined pressure from the environment external to the apparatus; and a flexible connection configured to permit the seal portion to move relative to the acoustic channel. In some of these embodiments the flexible connection may be further configured to resiliently locate the seal portion away from a seal surface when the seal portion experiences pressure less than or equal the predefined pressure from the environment external to the apparatus.

In such a way the apparatus can be both used and produce good acoustic performance due to the open acoustic channel but also be submersible or operated in pressure situations as the acoustic channel is closed by the seal when the pressure reaches a predefined level.

In at least one embodiment the acoustic window may comprise an acoustically transparent membrane.

Furthermore in some embodiments the apparatus may further comprise a transducer wherein the acoustic channel is configured to provide an acoustic pathway between the transducer and acoustic window.

In such embodiments the seal portion may be configured to cover and seal an acoustic port to close the acoustic channel, wherein the acoustic window is located adjacent the acoustic port. Also in such embodiments the seal portion may be configured to close the acoustic channel by co-operating with a further surface located over and at least partially separated from an acoustic port, wherein the acoustic window located over the further surface. The seal portion in some embodiments as described above may comprise an elastic bag, wherein the elastic bag comprises: a first window on at least one surface of the elastic bag configured to be the acoustic window, and a second window located adjacent to and on a surface other than the at least one surface, the second window co-operating with an acoustic port of at least one transducer.

The seal portion in some embodiments can comprise a plug configured to cooperate with a surface of an acoustic port to close the acoustic channel when the seal portion experiences pressure greater than a predefined pressure from the environment external to the apparatus.

Furthermore in some embodiments the seal portion can be a tubular member configured to constrict and close the acoustic channel when the seal portion experiences pressure greater than a predefined pressure from the environment external to the apparatus.

In some embodiments as described earlier the acoustic window may comprise a plurality of acoustic window parts, the seal portion may comprise a plurality of seal portion parts, and the acoustic channel may comprise a plurality of acoustic pathways wherein the plurality of seal portion parts may be configured to seal the acoustic pathways. The acoustic window in some embodiments can be configured to provide protection from liquid or particle ingress to the apparatus less than a second predefined pressure external to the apparatus, wherein the first predefined pressure is less than the second predefined pressure. For example as described previously the window may fail an ingress test if the pressure is greater than 1 metre of static water pressure but the seal configured to seal the acoustic channel before this pressure is reached.

In some embodiments the apparatus can further comprise a second seal portion connected to the flexible portion and configured to provide a second seal to the apparatus to define the acoustic channel.

As indicated above in some embodiments the pressure from the environment external to the apparatus can be liquid or water pressure.

It shall be appreciated that the term user equipment is intended to cover any suitable type of wireless user equipment, such as mobile telephones, headsets, portable data processing devices or portable web browsers. Furthermore, it will be understood that the term acoustic sound channels is intended to cover sound outlets, channels and cavities, and that such sound channels may be formed integrally with the transducer, or as part of the mechanical integration of the transducer with the device.

In general, the various embodiments of the invention may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof. The embodiments of this invention may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Further in this regard it should be noted that any blocks of the logic flow as in the Figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD.

The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), gate level circuits and processors based on multi-core processor architecture, as non-limiting examples.

Embodiments of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate. Programs, such as those provided by Synopsys, Inc. of Mountain View, California and Cadence Design, of San Jose, California automatically route conductors and locate components on a semiconductor chip using well established rules of design as well as libraries of pre-stored design modules. Once the design for a semiconductor circuit has been completed, the resultant design, in a standardized electronic format (e.g., Opus, GDSII, or the like) may be transmitted to a semiconductor fabrication facility or "fab" for fabrication.

As used in this application, the term 'circuitry' refers to all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) to combinations of circuits and software (and/or firmware), such as: (i) to a combination of processors) or (ii) to portions of processor(s)/software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions and (c) to circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present. This definition of 'circuitry' applies to all uses of this term in this application, including any claims. As a further example, as used in this application, the term 'circuitry' would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term 'circuitry' would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or similar integrated circuit in server, a cellular network device, or other network device.

The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of the exemplary embodiment of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention as defined in the appended claims.

Claims

CLAIMS:

1 . An apparatus comprising:

an acoustic window configured to provide an interface between an acoustic channel and an environment external to the apparatus;

a seal portion configured to close the acoustic channel when the seal portion experiences pressure greater than a predefined pressure from the environment external to the apparatus; and

a flexible connection configured to permit the seal portion to move relative to the acoustic channel.

2. The apparatus as claimed in claim 1 , wherein the flexible connection is configured to resiliently locate the seal portion away from a seal surface when the seal portion experiences pressure less than or equal the predefined pressure from the environment external to the apparatus.

3. The apparatus as claimed in claims 1 and 2, wherein the acoustic window comprises an acoustically transparent membrane.

4. The apparatus as claimed in claims 1 to 3, further comprising a transducer wherein the acoustic channel is configured to provide an acoustic pathway between the transducer and acoustic window.

5. The apparatus as claimed in claims 1 to 4, wherein the seal portion is configured to cover and seal an acoustic port to close the acoustic channel, wherein the acoustic window is located adjacent the acoustic port.

6. The apparatus as claimed in claims 1 to 4, wherein the seal portion is configured to close the acoustic channel by co-operating with a further surface located over and at least partially separated from an acoustic port, wherein the acoustic window located over the further surface.

7. The apparatus as claimed in claims 1 to 4, wherein the seal portion comprises an elastic bag, wherein the elastic bag comprises: a first window on at least one surface of the elastic bag configured to be the acoustic window, and a second window located adjacent to and on a surface other than the at least one surface, the second window co-operating with an acoustic port of at least one transducer.

8. The apparatus as claimed in claims 1 to 4, wherein the seal portion comprises a plug configured to co-operate with a surface of an acoustic port to close the acoustic channel when the seal portion experiences pressure greater than a predefined pressure from the environment external to the apparatus.

9. The apparatus as claimed in claims 1 to 4, wherein the seal portion is a tubular member configured to constrict and close the acoustic channel when the seal portion experiences pressure greater than a predefined pressure from the environment external to the apparatus.

10. The apparatus as claimed in claims 1 to 9, wherein the acoustic window comprises a plurality of acoustic window parts, wherein the seal portion comprises a plurality of seal portion parts, and the acoustic channel comprises a plurality of acoustic pathways wherein the plurality of seal portion parts are configured to seal the acoustic pathways.

11 . The apparatus as claimed in claims 1 to 10, wherein the acoustic window is configured to provide protection from liquid or particle ingress to the apparatus less than a second predefined pressure external to the apparatus, wherein the first predefined pressure is less than the second predefined pressure.

12. The apparatus as claimed in claims 1 to 1 1 , further comprising a second seal portion connected to the flexible portion and configured to provide a second seal to the apparatus to define the acoustic channel.

13. The apparatus as claimed in claims 1 to 12, wherein the pressure from the environment external to the apparatus is liquid or water pressure.

14. A method comprising:

providing with an acoustic window an interface between an acoustic channel and an environment external to an apparatus;

closing with a seal the acoustic channel when the seal experiences pressure greater than a predefined pressure from the environment external to the apparatus; and

permitting the seal portion to move relative to the acoustic channel with a flexible connection.

15. The method as claimed in claim 14, further comprising locating the seal portion away from a seal surface with the flexible connection when the seal experiences pressure less than or equal the predefined pressure from the environment external to the apparatus.