Keypad and microphone arrangement

Disclosed is a keypad and microphone arrangement for a communication device. The arrangement comprises: a key having a cap portion and a stem portion; a base layer attached to the stem portion; a key circuit to recognize activation of the key; a support member to support the key and base layer; a microphone located beneath the support member; a port in the base layer extending from an upper surface of the base, through an interior of the base layer, to a lower surface of the base layer. The support member has an opening extending from its top surface, through its interior, to its bottom surface. There is also an air channel connecting the microphone to ambient air above the cap portion, the air channel comprising the port and the opening. The stem portion and the cap portion are located about the port such that the cap portion extends fully over the port. The arrangement may be used in any communication device having voice reception capabilities.

FIELD OF INVENTION

The invention relates to a microphone arrangement for a voice communication device, in particular an arrangement relating to a layout of a microphone and a keypad.

BACKGROUND

In a voice communication device, a microphone and a speaker must be provided in order to allow a user to send and receive audio signals with another compatible device used by another person.

In a typical telephone, a handset is provided which is a shaped form having a microphone and a speaker positioned in a spaced relationship. Typically, both the microphone and the speaker are placed behind a series of ports to allow transmission of sounds to and from them to outside the handset. These ports provide benefits for the acoustic frequency response characteristics of the handset, but can be aesthetically distracting to the appearance of the handset. Further having exposed ports leaves the ports susceptible to blockage from ambient dust or dirt. Liquids spilled around the ports may also enter the port and may damage the devices underneath.

Meanwhile, portable communication devices, such as cellular phones, have smaller and smaller form factors. Positioning transducers for a cellular phone having a small form factor is a difficult task, because there is little area to place a port for a transducer.

There is a need for an arrangement which addresses deficiencies in the prior art of locating a transducer for a communication device.

SUMMARY

In a first aspect, a keypad and microphone arrangement for a communication device is provided. The arrangement comprises: a key having a cap portion and a stem portion; a base layer attached to the stem portion; a key circuit to recognize activation of the key; a support member to support the key and base layer; a microphone located beneath the support member; a port in the base layer extending from an upper surface of the base, through an interior of the base layer, to a lower surface of the base layer. The support member has an opening extending from its top surface, through its interior, to its bottom surface. There is also an air channel connecting the microphone to ambient air above the cap portion, the air channel comprising the port and the opening. The stem portion and the cap portion are located about the port such that the cap portion extends fully over the port.

In the arrangement, the key circuit may be located beneath the base layer. The key circuit may be mounted on a PCB. The PCB may have a second opening from its top surface through its interior to its bottom surface. Also, the arrangement may have: a second PCB for mounting the microphone thereon; and a support for the key circuit mounted to the second PCB and being located below the key circuit. The support may have a third opening from its top surface, through its interior to its bottom surface. The air channel further comprises the second and third openings.

In the arrangement, the air channel may extend vertically from the microphone to the port in a column.

In the arrangement, an opening for the port in the top surface of the base layer may be located about a corner of the stem.

In the arrangement, the stem may have an inward notch in its body in the corner of the stem portion.

In the arrangement, the microphone may be enclosed in a Faraday shield about the PCB.

In a second aspect, a wireless communication device is provided. The device comprises: an exterior frame; an antenna for transmitting wireless signals; a key having a cap and a stem; a base layer attached to the stem; a support member to support the keypad and the base layer; a key circuit to recognize activation of the key; a microphone located beneath the support member; a port in the base layer extending from an upper surface of the base, through an interior of the base layer, to a lower surface of the base layer; and an air channel connecting the microphone to ambient air above the cap, the air channel comprising the port and an opening in the support member extending from its top surface, through its interior, to its bottom surface. In the device, the stem and the cap are located about the port such that the cap extends fully over the port.

In the device, the key circuit may be located beneath the base and the key circuit may be mounted on a PCB. The PCB has a second opening from its top surface through its interior to its bottom surface. Also, the device further comprises: a second PCB for mounting the microphone thereon; and a support for the key circuit mounted to the second PCB. The support is located below the key circuit and has a third opening from its top surface, through its interior to its bottom surface. Further, the air channel comprises the second and third openings.

In the device, the air channel may extend vertically from the microphone to the port in a column.

In the device, an opening of the port in the top surface of the base layer may be located about a corner of the stem.

In the device, the microphone may be enclosed in a Faraday shield on the second PCB.

In a third aspect, a wireless handheld communication device is provided. It comprises: a housing having a front face; a display located proximately to a first end of the front face; a keypad located proximately to a second end of the front face, the second end being substantially opposite to the first end, the keypad having a plurality of keys allowing the entry of alphanumeric text to create textual messages to be wirelessly transmitted from the wireless handheld communications device; and a microphone for receiving voice, the microphone being located under the keypad with respect to a user's face. In the device the keypad has at least one audio input port that is located underneath a key of the keypad.

In the device, wherein the key of the keypad under which is the at least one audio input port may redirect air flow to the at least one audio input port.

In the device, air flow may be redirected in a substantially perpendicular manner.

In a fourth aspect, a wireless handheld communications device is provided. It comprises: a housing having a front face; a display located proximately to a first end of the front face; a keypad located proximately to a second end of the front face, the second end being substantially opposite to the first end, the keypad having a plurality of keys allowing the entry of characters, the entry of characters being used in wireless communications from the wireless handheld communications device; and a microphone for receiving voice, the microphone being located under the keypad with respect to a user's face. In the device, the keypad has at least one audio input port that is located underneath a key of the keypad.

In a fifth aspect, a wireless handheld communications device is provided. The device comprises: a housing having a front face; a display located near a first end of the front face; a keypad located proximately to a second end of the front face, the second end opposing the first end along a length of the front face, the keypad allowing an entry of characters; and a microphone located underneath the keypad. With the device, a user may select a text message mode of the wireless handheld communications device.

In other aspects various combinations of sets and subsets of the above aspects are provided.

DETAILED DESCRIPTION OF AN EMBODIMENT

The description which follows, and the embodiments described therein, are provided by way of illustration of an example, or examples, of particular embodiments of the principles of the present invention. These examples are provided for the purposes of explanation, and not limitation, of those principles and of the invention. In the description, which follows, like parts are marked throughout the specification and the drawings with the same respective reference numerals.

Referring toFIG. 1, communication device100is shown. Communication device100is preferably a wireless communication device such as a cellular phone, a personal digital assistant (PDA) or a wireless device providing voice and data transmission capabilities (such as text messaging or email capabilities). Communication device100has wireless transmission of voice capabilities, as provided by cellular communication devices known in the art. However, device100may also be a telephone, a cordless telephone, a handset for a telephone or any device providing voice communications. The main user interface elements of communication device100for its user are keypad102, display104and speaker106.

It will be appreciated that the layout of keys108within keypad102may be numeric, alphabetic, symbolic, alphanumeric or a combination of any of the above. It will also be appreciated that alphabetic keys may be arranged in the standard typist “QWERTY”-layout keyboard, a sequential layout or any other layout.

When a user activates communication device100to initiate a call, he enters a called telephone number via pressing appropriate keys108on keypad102. As each key108is pressed, display104presents the called telephone number as it is built. Upon connection of the call to the called telephone number, the user typically orients it such that speaker106is located near his ear and keypad102is located near his mouth. Behind the “A” key108A is port110. Port110forms part of an air channel to the interior of communication device100. At the end of the air channel, a microphone is located (not shown) which is a transducer to convert the audible energy in the user's spoken words to an electrical signal. Keys108are arranged in a spaced relationship such that there is an air gap112between sides of adjacent keys108to facilitate individual activation of keys108.

Port110is located underneath “A” key108A. As such, port110is hidden from sight from the user. “A” key108and its immediately adjacent keys108provide a physical barrier to impede foreign elements, such as dust and dirt from covering port110, which would attenuate the audio signals actually received by the microphone. As such, communication device100has a clean aesthetic appearance as port110is hidden when viewed from above. It will be appreciated in another embodiment, a corresponding port to port110may be located underneath a different key108.

Referring toFIG. 2, further detail on aspects of keypad108vis-á-vis the microphone are provided. Therein, exploded view200provides an exploded view of internal elements of communication device100. There are three main layers of internal elements: external layer202; keypad layer204; and PCB206. External layer202comprises external components exposed to the ambient environment about casing112. Keypad layer204is aligned to be located underneath external layer202and provides an electro-mechanical circuit to generate an electrical signal from activation of any key108for use by internal circuitry of device100. PCB206is located underneath keypad layer204and provides a substrate for supporting internal circuitry for device100. The internal circuits includes electronic components208, such as central processing units, radio frequency components, memory units, battery supplies, and microphone210. Embedded on PCB206are electrically-conductive tracks to make circuits for components208.

Microphone210preferably has a channel providing air access to the exterior of device100to function effectively. In the embodiment, a space-efficient channel is provided, wherein microphone is vertically aligned with port110. The channel is defined by a series of openings in each of the three layers. In external layer202, port110extends from its upper surface through its interior to its bottom surface in a preferably cylindrical channel. Keypad layer204has port212which extends from its top through its interior to its bottom. The upper opening of port212is aligned with the bottom opening of port110. Microphone210is preferably located to be directly underneath port212. As such, the air channel is defined by port110and port212. In other embodiments, a different number of internal ports may be present, placing their microphone either closer to, or further away from, port110. Additional acoustic insulators may also be provided between interface areas between ports and between a port and microphone210.

Referring toFIG. 3, further detail is provided on internal elements of device100in view300. External layer202comprises base section302, frame304and caps306. Base section302is a silicon-based elastomer formed as a plurality of stems308having webbing310therebetween to connect bases of stems308together. In other embodiments, some or every stem308may not be connected together by webbing310. Each key108is comprised of two portions: a cap306and a stem308. Cap306is fused to its associated stem308by an adhesive. Other bonding techniques, such as sonic welding, may also be used. Stem308is a support for cap306. Pressing on cap306causes its stem308to be pushed downward to engage an electrical contact for a circuit in keypad layer204. Further detail on this engagement is provided below. In the embodiment, stem308is a solid rectangular shape. However, any volume shape which will support cap306and engage the electrical contact will also be suitable. Frame304provides a top cover for base section302and also provides structural rigidity to keypad102. As such, frame304is preferably made from a sufficiently stiff material, such as a stamped piece of metal or a moulded piece of hard plastic.

Keypad layer204comprises keypad PCB312, a plurality of domes314and keypad dome sheet316. For each key108, keypad PCB312has an electrical circuit located immediately underneath it. The electrical circuit has a first section and a second section in a spaced relationship. Dome314sits above the first and second sections for each key108. Dome314is generally a thin, convex, compressible, electrically conductive element. All of domes314are held in place by dome sheet316, which has an adhesive side on it lower surface and a non-adhesive polished side on its upper surface. When key108is depressed, stem308is moved downward and a bottom portion of stem308contacts dome314to force it downward. Compression of dome314causes it to make contact with the first and second sections of keypad PCB312simultaneously, thereby completing an electrical contact between the sections. Circuitry of keypad PCB312then recognizes the completion of the contact and appropriate signals are provided to other circuits therein. Upon release of key108, dome314flexes upward, returns to its uncompressed shape and causes key108to move upward to its original, unpressed position. Such circuits and elements for making an electrical connection for a key in a keypad, such as key108, are known in the art.

PCB206has microphone210mounted onto it within shield can316. Shield can316provides a Faraday shield to isolate microphone210from electromagnetic interference. Such interference may originate from signals received and generated by an antenna (not shown) provided for device100. Shield can316has aperture318therein to allow sounds entering port110to ultimately enter shield can316and be exposed to microphone210. Shield can316is preferably made of metal and is shaped to completely enclose microphone210, but for aperture318, when microphone210is mounted onto PCB206. Shield can316is oblong in shape, but any suitable shape may be used. Alternate embodiments may dispense with having a shield can.

Gasket320is an annular ring and is dimensioned to fit within aperture318and is comprised of a compressible material. In the embodiment, it is compressible by approximately 40%. Gasket320is positioned such that its lower end rests against microphone210and its upper end extends towards the bottom surface of keypad support332. Other materials may be used if other compression characteristics are required. Alternate embodiments may dispense with having a gasket.

Keypad support322provides a raised bracket for PCB206to locate keypad layer202at an appropriate height in casing112, while allowing components208to be located on PCB206underneath it. In situ, sides of keypad support rest on the surface of PCB206and snap tabs in the sides engage with the bottom of PCB206to snugly secure keypad support322to PCB206. As such, keypad support322also provides a brace for keypad108as keys108are pressed. Aperture324in keypad support322provides an opening to continue the air channel from port110to microphone210and is vertically aligned with aperture318and the interior of gasket320. When keypad support322is secured to PCB206, gasket320is compressed, but it still maintains an internal cavity, thereby defining an acoustic channel for sound to travel through opening324in keypad support322directly to microphone210.

To adhere keypad layer204to elements associated with PCB206, double-sided adhesive tape326is provided. The bottom of keypad PCB312is affixed to the top of keypad support322by adhesive tape326. Opening328in adhesive tape326allows the air channel to be maintained from microphone210through keypad support322through adhesive tape326to keypad layer204.

Continuing with the air channel, in keypad layer204, port212is defined by opening330in keypad PCB312and opening332in dome sheet316. In base section302, opening334is provided for the air channel and aligns with opening332. In frame304, opening336has section336A which aligns with opening334.

Referring toFIG. 4, elements ofFIG. 3are shown in cross section providing a different view of the air channel. Therein, air channel400is comprised of a channel formed by ports110and212, openings336A,334,332,330,328and324and gasket to provide access to microphone210. It will be appreciated that in other embodiments, the air channel may have a different volume, a different cross section and a different location relative to the location of microphone210. In other embodiments, there may be multiple air channels and a series of air channels may be provided to connect a series of ports to the microphone. Therein, some of the ports, if not all of the ports, may be hidden by one or more keys and their covers. As seen, when key108is fully engaged, preferably there is still a gap between the bottom of cap306A and frame304, such that port110is not physically sealed by the bottom of cap306A. However, in other embodiments, cap306A may temporarily seal port110when key108is fully engaged, as long as the seal is broken upon release of key108.

Air channel400is completed by space402, located between caps306A and306B, to ambient air. While air channel400is complete, port110is obscured from view by cap306A and its adjacent cap306located to the left of cap306A. It will be appreciated that in other embodiments, cap306A may in further laterally extend across port110to provide a different degree of obscuring when viewed from above.

Referring toFIG. 5, a selection of keys108in keypad102are shown. “A” key108A is located amongst neighbouring keys108. Caps306of keys108are made of a polycarbonate material, although other materials known in the art of keypads may be used. Each of caps306is shown as a having a quadrilateral cross-section, however, any shape of cap306would also work in other embodiments. Such shapes include ovoid, rectangular and a general polygon. Port110is mostly, if not fully, obscured from view from above by cap306A. Caps immediately to the left, above and diagonally to the left and above cap306A assist in obscuring port110, when viewed from different angles from above. Gaps112provide spacing between keys108. In other embodiments, no gap112is provided. Therein, acoustic energy must reach port110by entering from the ambient environment to an exterior edge of keypad102then travelling through a gap defined by the bottom surface of caps306, the top of frame204and the sides of stems308to reach port110.

Each key is preferably painted with its associated symbol. Accordingly, “A” key108is painted with an “A” symbol on it. However, keys may also be silk screened, impressed with, embossed upon, its associated symbol(s). Painting or silk screening key108also obscures port110from sight when keypad102is viewed from above. In other embodiments, keys108may be covered with a semi-opaque paint. Alternatively, a substrate used to manufacture cap306may be sufficiently opaque to obscure port110.

Underneath each key108the outline of its associated stem308is shown. Keys108which are not associated with port110generally have rectangular-shaped footprints for their respective stems308. However, “A” key108is used to obscure port110. As such, the shape of stem308A is adjusted to allow placement of port110underneath cap306A. In particular, in the upper left corner of the footprint of stem308A, internal notch500is provided, which is excised from stem308A. Notch500provides more room around port110. Opening336in frame304is made to be slightly larger than the exterior dimension of port110. Alternative embodiments may have port110more fully, if not completely, enclosed within the footprint of stem308A. Alternative embodiments do not use a notch, when the dimensions of its cap306, stem208, port110and location of port110are arranged to sufficiently obscure sight of its port110from above.

In other embodiments, the external port for the enclosed transducer may be obscured from sight by a non-functional key or a decorative cover providing a raised cover to the external port.

In still other embodiments, the air channel and port may be integrated into at least a part of the key obscuring the port. For example, the air channel may be integrated into the stem of a key and the port may be on a side of the stem. Alternatively, the air channel may pass entirely through the stem and the cap, with the port being an opening on a surface of the cap, such as its top, side or exposed underside. In other embodiments, one or more caps or stems near the port may have cut-in channels therein, to provide additional alternative path(s) for sound energy to access the port.

It will be appreciated that the embodiment permits arrangement of an antenna, microphone210and keypad102in device100to be in close proximity to each other.

While aspects of the embodiment have been associated with a communication device, it will be appreciated that in other further embodiments, the keypad and microphone arrangement described herein may be applied to any device having a microphone and a keypad. For example, one such device is a device having a media play back component (such as a CD player) with (audio) recording capabilities.

Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the scope of the invention as outlined in the claims appended hereto.