U.S. patent application number 12/033976 was filed with the patent office on 2009-08-20 for device providing an improved keypad assembly for a portable electronic device.
This patent application is currently assigned to Research In Motion Limited. Invention is credited to Albert Murray Pegg, Roman Rak.
Application Number | 20090207054 12/033976 |
Document ID | / |
Family ID | 40954629 |
Filed Date | 2009-08-20 |
United States Patent
Application |
20090207054 |
Kind Code |
A1 |
Rak; Roman ; et al. |
August 20, 2009 |
DEVICE PROVIDING AN IMPROVED KEYPAD ASSEMBLY FOR A PORTABLE
ELECTRONIC DEVICE
Abstract
A keypad assembly for a wireless device is provided. The keypad
assembly comprises a circuit board, a keypad portion, a light
guide, and at least one friction device. The keypad portion has a
number of keys for physical actuation, each of the keys having an
actuator post attached to a back side of the key. The circuit board
has one or more electrical switches, the electrical switches
corresponding to keys of the keypad. The light guide is located
between the keypad portion and the circuit board. The light guide
has a number of holes formed therein. The holes provide paths for
respective actuator posts of the keys to travel through to contact
the respective electrical switches on the circuit board. The at
least one friction device is located in at least one of the holes
of the light guide. The friction device provides a physical barrier
limiting movement of the actuator post in a direction normal to the
direction of actuation and the friction device applies friction to
the side of the actuator post, thereby resisting movement of the
actuator post in the direction of actuation.
Inventors: |
Rak; Roman; (Waterloo,
CA) ; Pegg; Albert Murray; (Cambridge, CA) |
Correspondence
Address: |
OGILVY RENAULT LLP
1, Place Ville Marie, SUITE 2500
MONTREAL
QC
H3B 1R1
CA
|
Assignee: |
Research In Motion Limited
Waterloo
CA
|
Family ID: |
40954629 |
Appl. No.: |
12/033976 |
Filed: |
February 20, 2008 |
Current U.S.
Class: |
341/34 |
Current CPC
Class: |
H01H 2221/026 20130101;
H01H 2221/058 20130101; H01H 13/7065 20130101; H01H 2221/002
20130101; H01H 2221/062 20130101; H03K 2217/96042 20130101; G06F
3/023 20130101; H01H 13/14 20130101; H01H 2237/00 20130101 |
Class at
Publication: |
341/34 |
International
Class: |
H03K 17/94 20060101
H03K017/94 |
Claims
1. A keypad assembly for a wireless device, the keypad assembly
comprising: a keypad portion having a number of keys for physical
actuation, each of the keys having an actuator post attached to a
back side of the key; a circuit board having one or more electrical
switches, the electrical switches corresponding to the keys of the
keypad; a light guide located between the keypad portion and the
circuit board, the light guide having a number of holes formed
therein, the holes providing paths for respective actuator posts of
the keys to travel through to contact the respective electrical
switches on the circuit board; and at least one friction device
located in at least one of the holes of the light guide, the
friction device providing a physical barrier limiting movement of
the actuator post in a direction normal to a direction of
actuation, the friction device applying friction to at least one
side of the actuator post and resisting movement of the actuator
post in the direction of actuation.
2. The keypad assembly according to claim 1, wherein the at least
one friction device comprises a grommet having at least one
interference zone.
3. The keypad assembly according to claim 2, wherein the grommet is
round and has an outside circumference approximately equal to or
greater than an inside circumference of the holes in the light
guide.
4. The keypad assembly according to claim 3, wherein the grommet is
press-fit into the hole.
5. The keypad assembly according to claim 3, wherein the grommet is
moulded into the holes using a two-shot moulding process.
6. The keypad assembly according to claim 3, wherein the grommet
has a number of interference zones selected from the group
consisting of one, two, three, and four.
7. The keypad assembly according to claim 6, wherein the
interference zones are equally spaced about an inside circumference
of the grommet.
8. The keypad assembly according to claim 3, wherein the
interference zones are raised portions that extend inwardly from an
inside circumference of the grommet, thereby decreasing the inside
circumference of the grommet over a portion of the inside
circumference of the grommet.
9. The keypad assembly according to claim 8, wherein the
interference zones extend in length anywhere from a portion of an
axial length of the grommet to the entire axial length of the
grommet.
10. The keypad assembly according to claim 1, wherein the at least
one friction device comprises one or more members attached to an
inside circumference of the holes of the light guide.
11. The keypad assembly according to claim 10, wherein the number
of members in a single hole is selected from the group consisting
of one, two, three, or four.
12. The keypad assembly according to claim 11, wherein the members
are equally spaced about the inside circumference of the hole.
13. The keypad assembly according to claim 11, wherein the members
form raised portions that extend inwardly from the inside
circumference of the hole, thereby decreasing the inside
circumference of the hole over a portion of the inside
circumference of the hole.
14. The keypad assembly according to claim 13, wherein the members
extend anywhere in length from a portion of an axial length of the
hole to the entire axial length of the hole.
15. The keypad assembly according to claim 1, further comprising: a
bezel Frame located in front of the keypad portion, the bezel frame
defining an opening in the frame for each of the keys; and one or
more light emitting diodes connected to the circuit board for
providing light to the light guide, wherein the switches on the
circuit board are dome switches.
16. A device for use in a hole of a light guide of a keypad
assembly, the light guide being located between a keypad and a
circuit board, the hole providing a path for an actuator post of a
key of the keypad to travel through to contact a respective switch
on the circuit board, the device comprising: a grommet having at
least one interference zone, the grommet having an outside
dimension approximately equal to or greater than an inside
dimension of the hole, the interference zones being raised portions
that extend inwardly from the inside dimension of the grommet,
thereby decreasing the inside dimension of the grommet over a
portion of the inside dimension of the grommet.
17. The device according to claim 16, wherein the grommet is round,
the outside dimension of the grommet being an outside
circumference, the inside dimension of the hole being an inside
circumference, the grommet having an axial length, and the
interference zones extending in length anywhere from a portion of
an axial length of the grommet to the entire axial length of the
grommet.
18. A device for use in a hole of a light guide of a keypad
assembly, the light guide being located between a keypad and a
circuit board, the hole providing a path for an actuator post of a
key of the keypad to travel through to contact a respective switch
on the circuit board, the device comprising: one or more members
attached to an inside dimension of the hole of the light guide, the
members forming raised portions that extend inwardly from the
inside dimension of the hole, thereby decreasing the inside
dimension of the hole over a portion of the inside dimension of the
hole.
19. The device according to claim 18, wherein the hole is round and
has an axial length, the inside dimension of the hole being an
inside circumference, and the members extending anywhere from a
portion of the axial length of the hole to the entire axial length
of the hole.
20. A portable wireless device having a keypad assembly, the keypad
assembly comprising: a keypad portion having a number of keys for
physical actuation, each of the keys having an actuator post
attached to a back side of the key; a circuit board having one or
more electrical switches, the electrical switches corresponding to
the keys of the keypad; a light guide located between the keypad
portion and the circuit board, the light guide having a number of
holes formed therein, the holes providing paths for respective
actuator posts of the keys to travel through to contact the
respective electrical switches on the circuit board; and at least
one friction device located in at least one of the holes of the
light guide, the friction device providing a physical barrier
limiting movement of the actuator post in a direction normal to the
direction of actuation and the friction device applying friction to
the side of the actuator post, thereby resisting movement of the
actuator post in the direction of actuation.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to portable
devices, and more particularly to a device providing an improved
keypad assembly for a portable electronic device.
BACKGROUND
[0002] Portable electronic devices, such as cellular phones,
personal digital assistants, pagers, etc., have become increasingly
popular among consumers. Many portable electronic devices have
miniature integrated buttons, keyboards, or keypads of one variety
or another. One variety of keyboard or keypad that is used in
portable electronic devices is commonly referred to as a
film-in-plastic (FIP) keypad, also known as an in-mould-decoration
(IMD) keypad.
[0003] Conventional FIP or IMD keypads are generally difficult to
affix in place. As a result, the keypad may move around or vibrate,
radiating audible frequencies that may enter into a microphone of
the portable electronic device, causing unwanted noise or
interference during a telephone conversation or voice recording on
the device.
DESCRIPTION OF THE DRAWINGS
[0004] Reference will now be made to the drawings, which show by
way of example, embodiments of the present disclosure, and in
which:
[0005] FIG. 1 shows in block diagram form a wireless device
suitable for having a keypad in accordance with one embodiment;
[0006] FIG. 2 shows in block diagram form a communication system
suitable for providing the operating environment of the wireless
device of FIG. 1 in accordance with one embodiment;
[0007] FIG. 3 shows in block diagram form the contents of a memory
of the wireless device of FIG. 1;
[0008] FIG. 4 is a front view illustrating the wireless device of
FIG. 1;
[0009] FIG. 5 shows an exploded perspective view illustrating
various components and the assembly of a keypad suitable for use
with the wireless device of FIG. 1;
[0010] FIG. 6 shows an alternative exploded perspective view
illustrating various components and the assembly of a keypad
suitable for use with the wireless device of FIG. 1;
[0011] FIG. 7a shows a perspective view of one embodiment of a
friction device suitable for use with the keypad shown in FIGS. 5
and 6;
[0012] FIG. 7b shows a front plan view of the friction device shown
in FIG. 7a;
[0013] FIG. 8a shows a front plan view of another embodiment of
friction devices suitable for use with the keypad shown in FIGS. 5
and 6; and
[0014] FIG. 8b shows a front plan view of another embodiment of
friction devices suitable for use with the keypad shown in FIGS. 5
and 6.
[0015] It will be noted that throughout the appended drawings, like
features are identified by like reference numerals.
DETAILED DESCRIPTION
[0016] One aspect of the description provides a keypad assembly for
a wireless device. The keypad comprises a keypad portion having a
number of keys for physical actuation where each of the keys has an
actuator post attached to a back side of the key. The keypad
assembly comprises a circuit board having one or more electrical
switches where the electrical switches correspond to the keys of
the keypad. The keypad further has a light guide located between
the keypad portion and the circuit board. The light guide has a
number of holes formed therein. The holes provide paths for
respective actuator posts of the keys to travel through to contact
the respective electrical switches on the circuit board. The keypad
also has at least one friction device located in at least one of
the holes of the light guide. The friction device provides a
physical barrier limiting movement of the actuator post in a
direction normal to the direction of actuation and the friction
device applies friction to at least one side of the actuator post,
thereby resisting movement of the actuator post in the direction of
actuation.
[0017] Another aspect of the description provides a device for use
in a hole of a light guide of a keypad assembly. The light guide is
located between a keypad and a circuit board and the hole provides
a path for an actuator post of a key of the keypad to travel
through to contact a respective switch on the circuit board. The
device comprises a grommet having at least one interference zone,
the grommet having an outside dimension approximately equal to or
greater than an inside dimension of the hole in the light guide.
The interference zones are raised portions that extend inwardly
from the inside dimension of the grommet, thereby decreasing the
inside dimension of the grommet over a portion of the inside
dimension of the grommet.
[0018] Another aspect of the description provides a portable
wireless device having a keypad assembly. The keypad assembly
comprises a circuit board, a keypad portion, a light guide, and at
least one friction device. The keypad portion has a number of keys
for physical actuation where each of the keys has an actuator post
attached to a back side of the key. The circuit board has one or
more electrical switches corresponding to the keys of the keypad.
The light guide is located between the keypad portion and the
circuit board. The light guide has a number of holes formed
therein, where the holes provide paths for respective actuator
posts of the keys to travel through to contact the respective
electrical switches on the circuit board. The at least one friction
device is located in at least one of the holes of the light guide,
the friction device providing a physical barrier limiting movement
of the actuator post in a direction normal to the direction of
actuation and the friction device applies friction to at least one
side of the actuator post, thereby resisting movement of the
actuator post in the direction of actuation.
[0019] Reference is first made to FIG. 1, which shows a block
diagram illustrating a portable wireless device 102 that has a
keyboard or keypad in accordance with one embodiment of the present
disclosure. The wireless device 102 communicates through a wireless
communication network 104. The wireless network 104 includes
antenna, base stations, and supporting radio equipment as for
supporting wireless communications between the wireless device 102
and other devices connected to wireless network 104. The wireless
network 104 may be coupled to a wireless network gateway and to a
wide area network, shown in FIG. 2.
[0020] In one embodiment, the wireless device 102 is a two-way
communication device having at least voice and/or data
communication capabilities, including the capability to communicate
with other computer systems. In one embodiment, the wireless device
102 is a handheld device. Depending on the functionality provided
by the wireless device 102, it may be referred to as a data
messaging device, a two-way pager, a cellular telephone with data
messaging capabilities, a wireless Internet appliance, a data
communication device (with or without telephony capabilities), or a
portable media or music player. The wireless device 102 may
communicate with any one of a plurality of fixed transceiver
stations within its geographic coverage area.
[0021] The wireless device 102 may incorporate a communication
subsystem 112, which includes a receiver 114, a transmitter 116,
and associated components, such as one or more antenna elements 118
and 120, local oscillators (LOs) 122, and a processing module such
as a digital signal processor (DSP) 124. In one embodiment, the
antenna elements 118 and 120 may be embedded or internal to the
wireless device 102. As will be apparent to those skilled in the
field of communications, the particular design of the communication
subsystem 112 depends on the wireless network 104 in which the
wireless device 102 is intended to operate.
[0022] The wireless device 102 may send and receive communication
signals over the wireless network 104 after the required network
registration or activation procedures have been completed. Signals
received by the antenna 118 through the wireless network 104 are
input to the receiver 114, which may perform such common receiver
functions as signal amplification, frequency down conversion,
filtering, channel selection, etc., as well as analog-to-digital
(A/D) conversion. A/D conversion of a received signal allows more
complex communication functions such as demodulation and decoding
to be performed in the DSP 124. In a similar manner, signals to be
transmitted are processed, including modulation and encoding, for
example, by the DSP 124. These DSP-processed signals are input to
the transmitter 116 for digital-to-analog (D/A) conversion,
frequency up conversion, filtering, amplification, and transmission
to the wireless network 104 via the antenna 120. The DSP 124 not
only processes communication signals, but also provides for
receiver and transmitter control. For example, the gains applied to
communication signals in the receiver 114 and the transmitter 116
may be adaptively controlled through automatic gain control
algorithms implemented in the DSP 124.
[0023] Network access is associated with a subscriber or user of
the wireless device 102 via a memory module, such as a memory
module 130, which may be a Subscriber Identity Module (SIM) card
for use in a GSM network or a USIM card for use in a UMTS. The SIM
card is inserted in or connected to an interface 132 of the
wireless device 102 in order to operate in conjunction with the
wireless network 104. Alternatively, the wireless device 102 may
have an integrated identity module for use with systems such as
Code Division Multiple Access (CDMA) systems.
[0024] The wireless device 102 also includes a battery interface
136 for receiving one or more rechargeable batteries 138. The
battery 138 provides electrical power to at least some of the
electrical circuitry in the wireless device 102, and the battery
interface 136 provides a mechanical and electrical connection for
the battery 138. The battery interface 136 is coupled to a
regulator (not shown) which provides power V+ to the circuitry of
the wireless device 102.
[0025] The wireless device 102 includes a microprocessor 140 which
controls the overall operation of the wireless device 102.
Communication functions, including at least data and voice
communications, are performed through the communication subsystem
112. The microprocessor 140 also interacts with additional device
subsystems such as a display 142, a flash memory 144, a random
access memory (RAM) 146, a read-only memory (ROM) 148, auxiliary
input/output (I/O) subsystems 150, a Universal Serial Bus (USB)
port 152, a keyboard or keypad 154, a speaker or audio port 156 for
connecting to, for example a set of headphones, a microphone 158, a
clickable thumbwheel, thumbwheel, or set of scroll buttons 160, a
short-range communications subsystem 162, and any other device
subsystems generally designated as 164. Some of the subsystems
shown in FIG. 1 perform communication-related functions, whereas
other subsystems may provide "resident" or on-device functions.
Notably, some subsystems, such as the keypad 154, the display 142,
and the clickable thumbwheel 160, for example, may be used for both
communication-related functions, such as entering a text message
for transmission over the wireless network 104, and executing
device-resident functions such as a calculator or task list.
Operating system software used by the microprocessor 140 is
preferably stored in a persistent store such as the flash memory
144, which may alternatively be the ROM 148 or similar storage
element. Those skilled in the art will appreciate that the
operating system, specific device applications, or parts thereof,
may be temporarily loaded into a volatile store such as the RAM
146.
[0026] The microprocessor 140, in addition to its operating system
functions, enables execution of software applications on the
wireless device 102. A predetermined set of applications that
control basic device operations, including data and voice
communication applications, will normally be installed on the
wireless device 102 during or after manufacture. The wireless
device 102 may include a personal information manager (PIM)
application having the ability to organize and manage data items
relating to a user such as, but not limited to, instant messaging,
email, calendar events, voice mails, appointments, and task
items.
[0027] The PIM and/or media applications have the ability to send
and receive data items via either the wireless network 104 or a
link to a computer system. The link to the computer system may be
via the serial port 152 or the short-range communications subsystem
162. Additional applications may also be loaded onto the wireless
device 102 through the wireless network 104, the auxiliary I/O
subsystem 150, the serial port 152, the short-range communications
subsystem 162, or any other suitable subsystem 164, and installed
by a user in the RAM 146 or a non-volatile store such as the ROM
148 for execution by the microprocessor 140. Such flexibility in
application installation increases the functionality of the
wireless device 102 and may provide enhanced on-device functions,
communication-related functions, or both. For example, secure
communication applications may enable electronic commerce functions
and other such financial transactions to be performed using the
wireless device 102.
[0028] In a data communication mode, a received data signal
representing information such as a text message, an email message,
a media file to be transferred, or Web page download will be
processed by the communication subsystem 112 and input to the
microprocessor 140. The microprocessor 140 will further process the
signal for output to the display 142 or alternatively to the
auxiliary I/O device 150. A user of the wireless device 102 may
also compose data items, such as email messages, for example, using
the keypad 154 and/or the clickable thumbwheel 160 in conjunction
with the display 142 and possibly the auxiliary I/O device 150. The
keypad 154 may be either a complete alphanumeric keypad or
telephone-type keypad. In one embodiment, the keypad 154 may be a
film-in-plastic (FIP) or in-mould-decoration (IMD) keypad, which is
described in more detail below in connections with FIGS. 5-8.
[0029] For voice communications, the overall operation of the
wireless device 102 is similar, except that the received signals
would be output to the speaker or audio port 156 and signals for
transmission would be generated by a transducer such as the
microphone 158. Alternative voice or audio I/O subsystems, such as
a voice message recording subsystem, may also be implemented on the
wireless device 102. Although voice or audio signal output is
typically accomplished primarily through the speaker or audio port
156, the display 142 may also be used to provide an indication of
the identity of a calling party, duration of a voice call, or other
voice call related information. Stereo headphones may also be used
in place of the speaker 156.
[0030] The serial port 152 is normally implemented in a personal
digital assistant (PDA) type communication device for which
synchronization with a user's computer is a desirable, albeit
optional, component. The serial port 152 enables a user to set
preferences through an external device or software application and
extends the capabilities of the wireless device 102 by providing
for information, media file, or software downloads to the wireless
device 102 other than through the wireless network 104.
[0031] The short-range communications subsystem 162 is an
additional optional component which provides for communication
between the wireless device 102 and different systems or devices,
which need not necessarily be similar devices. For example, the
subsystem 162 may include an infrared device and associated
circuits and components, or a wireless bus protocol compliant
communication mechanism such as a Bluetooth.TM. communication
module to provide for communication with similarly-enabled systems
and devices (Bluetooth.TM. is a registered trademark of Bluetooth
SIG, Inc.). In another embodiment, the short-range communications
subsystem 162 may be a wireless networking communications
subsystem, conforming to IEEE 802.11 standards such as 802.11b,
802.11g, and/or 802.11n.
[0032] Reference is next made to FIG. 2, which shows a
communication system 200 suitable for use with the wireless device
102 shown in FIG. 1. The communication system 200 generally
includes one or more wireless devices 102 (only one of which is
shown in FIG. 2) and the wireless network 104. The wireless network
104 may include a wireless Wide Area Network (WAN) 202, a Wireless
Local Area Network (WLAN) 204, and/or other interfaces 206 (which
may not necessarily be wireless).
[0033] Referring to FIG. 2, the wireless WAN 202 may be implemented
as a packet-based cellular or mobile network that includes a number
of base stations 208 (one of which is shown in FIG. 2) where each
of the base stations 208 provides wireless Radio Frequency (RF)
coverage to a corresponding area or cell. The wireless NAN 202 is
typically operated by a cellular network service provider that
sells subscription packages to users of the wireless devices 102.
The wireless WAN 202 comprises a number of different types of
networks, for example, Mobitex Radio Network, DataTAC, GSM (Global
System for Mobile Communication), GPRS (General Packet Radio
System), TDMA (Time Division Multiple Access), CDMA (Code Division
Multiple Access), CDPD (Cellular Digital Packet Data), iDEN
(integrated Digital Enhanced Network) or various other third
generation networks such as EDGE (Enhanced Data rates for GSM
Evolution), UMTS (Universal Mobile Telecommunications Systems), or
Evolution-Data Optimized (EV-DO).
[0034] As shown in FIG. 2, the communications system 200 also
includes a wireless network gateway 210 and one or more network
provider systems 212. The wireless network gateway 210 provides
translation and routing services between the network provider
system(s) 212 and the WAN 202, which facilitates communication
between the wireless devices 102 and other devices (not shown)
connected, directly or indirectly, to the network provider system
212.
[0035] The WLAN 204 comprises a network which in some examples
conforms to IEEE 802.11 standards such as 802.11b, 802.11g, and/or
802.11n; however, other communications protocols may also be used
for the WLAN 204. The WLAN 204 includes one or more wireless RF
Access Points (AP) 214 (one of which is shown in FIG. 2) that
collectively provide a WLAN coverage area. For the embodiment
depicted in FIG. 2, the WLAN 204 is operated by an enterprise (for
example, a business or university in a building or campus type
environment) and the access points 214 are connected to an access
point (AP) interface 216. The AP interface 216 provides translation
and routing services between the access points 214 and the network
provider system 212 to facilitate communication between two or more
of the wireless devices 102 and other devices (e.g., such as
desktop computers) connected, directly or indirectly, to the
network provider system 212. The AP interface 216 is implemented
using a computer, for example, a server running a suitable computer
program or software.
[0036] According to one embodiment, the other interfaces 206 may be
implemented using a physical interface indicated by reference 218.
The physical interface 218 includes an Ethernet, Universal Serial
Bus (USB), Firewire, or infrared (IR) connection implemented to
exchange information between the network provider system 212 and
the wireless device 102.
[0037] The network provider system 212 comprises a server or server
modules or a number of servers or server modules which are
typically located behind a firewall (not shown). The network
provider system 212 may include a number of modules including a
mobile data delivery module 220. Various modules running on the
network provider system 212 may be implemented as a number of
services running on a single server or as a number of
interconnected servers each running a software program to implement
the functionality of the respective module. The network provider
system 212 provides access for the wireless devices 102, through
either the wireless WAN 202, the WLAN 204, or the other connection
206 to the devices connected, for example, through an enterprise
network 224 (e.g., an intranet), to the network provider system
212. In one embodiment, the data delivery module 220 is implemented
on a computer, such as the network provider system 212.
[0038] The enterprise network 224 comprises a local area network,
an intranet, the Internet, a direct connection, or combinations
thereof. The enterprise network 224 may comprise an intranet for a
corporation or other type of organization. In at least some
embodiments, the network provider system 212 is part of the
enterprise network 224, and is located behind a corporate firewall
and connected to the wireless network gateway 210 through the
Internet. A computer 222 (e.g., a desktop or laptop computer)
belonging to the user of the wireless device 102 is typically
connected to the enterprise network 224. As described earlier, the
wireless device 102 may be temporarily and directly connected to
the computer 222 using, for example, the serial port 152. This
direct connection may make use of a cradle or docking station
connected to a serial port of the computer 222, where the mobile
device 102 is placed in the cradle, therefore completing the serial
connection between the mobile device 102 and the computer 222.
Alternatively, the wireless device 102 may communicate with the
computer 222 using the communication subsystem 112 and the WAN 202
and/or the short-range communications subsystem 162 and the WLAN
204.
[0039] As shown in FIG. 2, an application/content server 226 may be
connected to the enterprise network 224 and also to another
network, for example a Wide Area Network (WAN) 228. In some
embodiments, an email server 232 and/or the content server 226 form
part of the enterprise network 224. The WAN 228 may further connect
to other networks. The WAN 228 may comprise or be configured with
the Internet, a direct connection, a LAN, a wireless communication
link, or any combination thereof. Content providers, such as Web
servers, may be connected to the WAN 228, an example of which is
shown in FIG. 2 as an origin server 230.
[0040] According to one embodiment, the mobile data delivery module
220 provides connectivity between the wireless WAN 202 and the WLAN
204 and the other connection 206 and devices and/or networks
connected directly or indirectly to the network provider system
212. In one embodiment, the connectivity provided may be Hypertext
Transfer Protocol (HTTP) based connectivity providing an Internet
based service connection to devices connected to the wireless WAN
202, the WLAN 204, or the other connection 206 and devices and/or
networks connected directly or indirectly to the network provider
system 212. The network 224, the application/content server 226,
the WAN 228, and the origin server 230, are individually and/or
collectively in various combinations a content source for the
network provider system 212. It will be appreciated that the system
shown in FIG. 2 comprises but one possible communication network or
configuration of a multitude of possible configurations for use
with the wireless devices 102.
[0041] Reference is next made to FIG. 3, which shows a block
diagram illustrating a memory 300 of the wireless device 102. The
memory 300 has various software components for controlling the
wireless device 102 and may include, for example, the flash memory
144, the RAM 146, the ROM 148, the memory module 130 and/or the
other device subsystems 164. In accordance with one embodiment, the
wireless device 102 is intended to be a multi-tasking wireless
communications device configured for sending and receiving data
items and for making and receiving voice calls that also includes
various applications enabling users to listen to music, watch video
files, play games, view picture files, surf the internet
wirelessly, etc. To provide a user-friendly environment to control
the operation of the wireless device 102, an operating system (OS)
302 resident on the wireless device 102 provides a basic set of
operations for supporting various applications typically operable
through a graphical user interface (GUI) 304. For example, the
operating system 302 provides basic input/output system features to
obtain input from the auxiliary I/O 150, the keypad 154, the
clickable thumbwheel 160, and other input devices, and to
facilitate output to the user via the display 142. The GUI 304 is
typically a component of the operating system 302. One or more
software modules 306 for managing communications or providing a
personal digital assistant (PDA) or other functions may also be
included.
[0042] The memory 300 also includes an email and calendar client,
which may be combined in, for example, a PIM application having
email-based calendaring and scheduling functions. Typically, the
PIM is installed as one of the software modules 306. The memory 300
also includes a keypad related control module 308 for managing I/O
function related to the keypad 154 of the wireless device 102. The
keypad control module 308 may be part of the operating system 302.
Further, the memory 300 typically includes a number of user files
or settings 310 which store, for example, media or document files
belonging to the user and configuration settings for various
applications.
[0043] Thus, the wireless device 102 includes computer executable
programmed instructions for directing the wireless device 102 to
implement various applications. The programmed instructions may be
embodied in the one or more software modules 306 resident in the
memory 300 of the wireless device 102. Alternatively, the
programmed instructions may be tangibly embodied on a computer
readable medium (such as a DVD, CD, floppy disk or other storage
media) which may be used for transporting the programmed
instructions to the memory 300 of the wireless device 102.
Alternatively, the programmed instructions may be embedded in a
computer-readable, signal-bearing medium that is uploaded to the
wireless network 104 by a vendor or supplier of the programmed
instructions, and this signal-bearing medium may be downloaded
through one or more of the interfaces 112, 150, 152, 162 to the
wireless device 102 from, for example, the wireless network 104 by
end users.
[0044] Reference is next made to FIG. 4, which shows a front view
of the wireless device 102. As mentioned above, the wireless device
102 may be a data and voice-enabled handheld device. The wireless
device 102 includes a casing 402, the data or serial port 152, the
display screen 142, the graphical user interface (GUI) 304, the
keypad 154, the clickable thumbwheel or scroll buttons 160a or
other device for navigation such as a trackball 160b, one or more
input buttons 404 (e.g., select, cancel, talk, play, stop, fast
forward, rewind, next, previous buttons), signal inputs/outputs 406
(e.g., direct wire connection or inductive coupling power connector
input, microphone, speaker, data interface input, etc.), and an
audio port 407. Additionally, the wireless device 102 may have a
number of navigation control buttons represented by numerals 409a
and 409b. The navigation control buttons 409 may provide a number
of functions such as a send and/or end key for a mobile telephone
application of the wireless device 102, a menu key, an escape key,
etc. The functions of the navigation control buttons 409 may be
user configurable. Internally, the wireless device 102 includes one
or more circuit boards (not shown), the microprocessor 140 (FIG.
1), the memory 300 (FIG. 3), the battery 138 (FIG. 1), the antennae
118, 120 (FIG. 1), etc., which may all be coupled to the signal
inputs/outputs 406, the keypad 154, the display screen 142, the
clickable thumbwheel 160, etc.
[0045] The microprocessor 140 is typically coupled to one or more
input devices (e.g., the buttons 404, the keypad 154, the clickable
thumbwheel 160) for receiving user commands or queries and the
display 142 for displaying the results of these commands or
queries. For example, user queries may be transformed into a
combination of commands for producing one or more tables of output
data which may be incorporated in one or more display pages for
presentation to the user. The microprocessor 140 is also coupled to
the memory 300.
[0046] A user may interact with the wireless device 102 and its
software modules 306 using the GUI 304. The GUI 304 is controlled
by the operating system 302 (FIG. 3) and provides a display format
enabling the user to choose commands, execute application programs,
manage computer files, and perform other functions by selecting
pictorial representations (i.e., icons), or selecting items from a
menu through the use of an input or pointing device such as the
clickable thumbwheel 160 and/or the keypad 154. Generally, the GUI
304 is used to convey information and receive commands from users
and generally includes a variety of GUI objects or controls
including icons, toolbars, drop-down menus, pop-up menus, text,
dialog boxes, buttons, etc. A user typically interacts with the GUI
304 presented on the display 142 by using an input or pointing
device to position a pointer or cursor 408 over an object 410
(i.e., "pointing" at the object) and by "clicking" on the object
410 (e.g., by depressing the thumbwheel 160 or a button on the
keyboard 154, etc.). This is often referred to as a point-and-click
or selection operation. Typically, the object 410 may be
highlighted (e.g., shaded) when it is selected or pointed at by the
pointer or cursor 408 to indicate that the object 410 is
selectable.
[0047] Typically, a GUI-based system presents application, status,
and other information to the user in windows appearing on the
display 142. A window 412 is a display area shown within the
display 142, typically rectangular, in which a user may view an
application or document. The window 412 may be open, closed,
displayed full screen, reduced to an icon, increased or reduced in
size, or moved to different areas of the display 142. Multiple
windows 412 may be displayed simultaneously. For example, the
windows 412 may be displayed within other windows, overlapped with
other windows, or tiled within the display area.
[0048] Reference is next made to FIGS. 5 and 6, which show exploded
perspective views illustrating the various components and the
assembly of the keypad 154 suitable for use with the wireless
device of FIG. 1. As shown in FIGS. 5 and 6, the keypad 154
includes a keypad portion 510, a light guide 512, an electrical
switch assembly or printed circuit board (PCB) 514 (FIG. 6) and the
casing 402. In one example, the electrical switch assembly 514 may
include a number of dome switches 516, typically one dome switch
516 for each key. In one example, the keypad portion 510 may be a
film-in-plastic (FIP) or an in-mould-decoration (IMD) keypad having
a number of keys 518. In one example, the casing 402 may be bezel
frame having a separate hole in the housing or casing 402 for each
of the keys 518. The keys 518 each have a contact surface on the
front side where a user may push down on a particular key and an
actuator post 520 (shown more clearly in connection with FIG. 6)
connected to the back side of each key 518. When the user depresses
the front surface of a key 518, the actuator post 520 of the
respective key 518 travels in the direction of actuation and
contacts a respective dome switch 516 (FIG. 6) thereby closing an
electrical contact of the associated electrical dome switch 516
allowing the processor 140 to detect the key depression.
[0049] The light guide 512 includes a number of holes 522 through
which the actuator posts 520 travel in order to contact the
electrical switches 516. The electrical switch assembly 514 also
includes a number of optional light emitting diodes 524 (FIG. 6)
that emit light. The light emitted by the light emitting diodes 524
travels through and/or is refracted through the light guide 512,
which in one example may be constructed of acrylic, and arrives at
the keypad portion 510, thereby illuminating the keypad portion 510
when the user wishes to use the portable wireless device 102 in
dark locations. The holes 522 of the light guide 512 have an inside
diameter that is larger than the outside diameter of the actuator
posts 520, connected to the back side of the keys 518. This allows
for easy assembly of the keypad 154 and provides the actuator posts
520 with enough clearance to freely travel in the direction of
actuation when the respective keys 518 are depressed by the user.
However, this larger diameter of the holes 522 also allows the
actuator posts 520 to travel laterally with respect to the light
guide 512, thereby allowing the entire keypad portion 510 to travel
laterally as much as is permitted by the casing 402 bezel frame
that surrounds each of the keys 518. Additionally, the larger
diameter of the holes 522, with respect to the actuator posts 520,
means that the actuator posts 520 are generally not contacting the
inside diameter of the holes 522. Rather, the actuator posts 520
float freely within the holes 522. This provides an additional
degree of freedom to the keys 518, allowing the keys 518 to travel
freely in the direction of actuation, as much as is permitted by
the casing 402 bezel frame that surrounds each of the keys 518 and
contacts the top surface of the keypad portion 510 in between the
keys 518.
[0050] The embodiment of the keypad 154 where the keypad 154
interacts with the casing 402 that is a bezel frame having a
separate hole for each of the keys 518 has many beneficial
characteristics compared to alternative designs, including the
prevention of key wobble and better ergonomics. However, the
freedom of the keys 518 to move, to some extent, in all three
spatial directions can sometimes result in vibration or rattling,
which is undesirable in devices such as the portable wireless
device 102, which may include a microphone 158 for voice recording
or voice calls.
[0051] The freedom of the keys 518 may be limited with the use of a
friction device 530, which is placed inside at least one of the
holes 522. In one example, the friction device 530 may be a grommet
and the friction device 530 has an outside dimension that is equal
to or greater than the inside dimension of the hole 522, so as to
be suitably secured within the hole 522. The friction device 530
contacts the sides of the respective actuator posts 520, thereby
restricting the lateral motion of actuator posts 520 (also referred
to as movement of the actuator post 520 in a direction normal to
the axis of the friction device) and, as a result, the entire
keypad portion 510. Additionally, since the friction device 530
also applies friction to the sides of the actuator posts 520, the
friction device 530 also makes it more difficult for the actuator
posts 520 to travel in the direction of actuation without an
associated threshold force being applied to the top of the keys 518
by the user. In the event that the friction device 530 is found to
apply too much friction to the side of the actuator posts 520, this
can be counteracted with appropriate choice of the dome switches
516. For example, 1.0, 1.35, and 1.6 Newton dome switches are
readily available in the market place. Therefore, if the use of the
friction device 530 is found to make it too difficult for the user
to depress the keys 518, a dome switch that requires less force to
be actuated may be selected for use with the keypad assembly
154.
[0052] In one aspect, the dimensions and material of the friction
device 530 are suitably chosen so as to interfere with the sides of
the actuator posts 520 at the tolerance limits of the actuator post
520 and hole 522 interface. The friction device 530 applies enough
friction to the sides of the actuator post 520 to substantially
reduce the likelihood that a key 518 will travel in the direction
of actuation without the key being depressed by the user of the
wireless device 102. The friction device 530 also serves as a
physical barrier to limit the lateral movement of the actuator post
520. Both of these effects of limiting the travel of the key 518 in
the direction of actuation, as well as laterally, aim to suitably
reduce the vibration of the keypad portion 510 without adversely
affecting the tactility of the keypad assembly 154.
[0053] FIGS. 5 and 6 show two exemplary embodiments of the friction
device 530. The friction device 530 shown in FIG. 5 is round and
may be easily placed within the holes 522. The friction device 530
shown in FIG. 6 comprises two separate elongated members, each of
which may be affixed to the inside circumference of holes 522 and
may be secured in place with a suitable adhesive. In one example,
the friction device 530 may be constructed of silicon or any
suitable silicon compound. However, the friction device 530 may be
constructed of any suitable material. Examples of various
embodiments of friction devices 530 are discussed in more detail
below in connections with FIGS. 7a, 7b, 8a, and 8b.
[0054] Reference is now made to FIGS. 7a and 7b. FIG. 7a
illustrates a perspective view of one embodiment of the friction
device 530. FIG. 7b illustrates a top plan view of the friction
device shown in FIG. 7a. In the embodiment shown in FIG. 7, the
friction device 530 may be round and may have a number of
interference zones 532. The interference zones 532 may also be
referred to as interference protrusions or friction mechanisms. In
the example where the friction device 530 is round, the friction
device 530 may be referred to as a grommet. The grommet may be
press fitted into the holes 522 of the light guide 512.
Alternatively, the friction device 530 may be moulded into the
holes 522 of the light guide 512. In one example, the friction
device 530 may be moulded into the holes 522 using a two-shot
moulding process. The light guide 512 may receive any number of
friction devices 530, from a single friction device 530 up to a
maximum of one friction device 530 for each of the holes 522. In
cases where the keypad portion 510 is a single FIP or IMD keypad,
the use of a single friction device 530 provides a significant
improvement, in particular with regards to reducing the lateral
movement of the keypad portion 510. In one embodiment, anywhere
from two to eight friction devices 530, such as the grommets shown
in FIG. 7, may be used in the holes 522.
[0055] The friction devices 530 may have any number of interference
zones 532. Additionally, the interference zones 532 may be of any
suitable shape or size. In the example shown in FIG. 7, there are
three interference zones 532, the minimum number needed for one
friction device 530 to substantially limit the motion of one of the
actuator posts 520 in a single plane normal to the direction of
actuation. The interference zones 532 shown in FIG. 7 do not span
the entire height of the friction device 530 (i.e., the height
being defined in the direction of actuation or in the axial
direction of an actuator post 520), as shown in FIG. 7a. However,
the interference zones 532 may be of any suitable height, and in
one embodiment, may span the entire height or axial length of the
friction device 530. One objective in designing the shape and size
of the interference zones 532 is to keep the interference zones 532
as small as possible such that the interference zones 532 interfere
with the actuator posts 520 at the tolerance limits of the
interface between the holes 522 and the actuator posts 520.
Expressed another way, in one embodiment, the interference zones
532 may be designed such that, if the holes were as small as
possible, yet still within the design tolerance limits, and the
actuator posts were as large as possible, yet still within the
design tolerance limits, the threshold would be reached where there
would be interference between the interference zones 532 and the
actuator posts 520. In one embodiment, there may be a generous
clearance between adjacent interference zones 532, indicated by
numeral 534. The clearance 534 allows for different shapes of
actuator posts 520 to be used. For example, the actuator posts 520
may be circular, square, triangular, hexagonal, octagonal, oval,
etc., or any other suitable shape.
[0056] In one embodiment where the friction device 530 is a
grommet, the interference zones 532 may be equally spaced about the
insider circumference of the grommet. The interference zones 532
are generally raised portions that extend inwardly from the inside
circumference of the grommet, thereby decreasing the inside
circumference of the grommet over a portion of the inside
circumference of the grommet. The interference zones 532 may extend
in length anywhere from a portion of the axial length of the
grommet to the entire axial length of the grommet.
[0057] In another embodiment where the friction device 530
comprises one or more elongated members attached in the inside of
the hole 522, the members may be equally spaced about the inside
circumference of the hole 522. The members generally form raised
portions that extend inwardly from the inside circumference of the
hole 522, thereby decreasing the inside circumference of the hole
over a portion of the inside circumference of the hole. The members
may extend anywhere in length from a portion of the axial length of
the hole to the entire axial length of the hole. Generally, the
axial length of the hole 522 will be approximately equal to the
thickness of the light guide 512.
[0058] Reference is now made to FIGS. 8a and 8b, which show a
number of alternative embodiments of friction devices 530. The
friction devices 530 are shown in an array to give some indication
of how the friction devices 530 may be arranged in the holes 522 of
the light guide 512. For clarity of description, new reference
numbers are adopted for FIGS. 8a and 8b.
[0059] Referring first to FIG. 8a, two friction devices 802,
individually indicated as 802a and 802b, are shown. The friction
devices 802a and 802b, in the depicted example, may also be
referred to as grommets. The friction devices 802a and 802b each
have two interference zones 804a and 804b, respectively. Therefore,
the friction devices 802 differ principally from the friction
device 530 shown in FIG. 7 in the number of interference zones that
exist. Therefore, the friction devices 802a and 802b are generally
the same as each other, although one is rotated ninety degrees with
respect to the other, to show how the friction devices 802a and
802b would be installed in the holes 522. One of the objectives of
the design of the friction devices 802 may be to apply some
friction to the sides of the actuator posts 520, but limited to an
amount of friction that is needed to substantially reduce unwanted
vibration of the keypad portion 510 without adversely affecting the
tactility of the keys 518. With each additional interference zone
804 that is added to a particular friction device 802, the
potential for reduced tactility of the key 518 to which the
associated actuator post 520 is connected increases. Hence, the
friction devices 802 each having two interference zones 804 may
represent an improvement over the friction device 530, having three
interference zones 532. In some embodiments, the keypad portion 510
is a single FIP or IMD keypad. Therefore, in some embodiments, it
may be desirable to reduce the number of interference zones 804 of
each friction device 802, but use more friction devices 802 in the
light guide 512
[0060] For example, the friction device 802a shows two interference
zones 804a positioned in the horizontal direction of FIG. 8a (e.g.,
in the X direction). The friction device 802b shows two
interference zones 804b positioned in the vertical direction of
FIG. 8a (e.g., in the Y direction). When the friction device 802a
is fitted into one of the holes 522 of the light guide 512, the
interference zones 804a of the friction device 802a will limit
movement of a respective actuator post 520 in the +/- X direction
because the interference zones 804a serve as a physical barrier
preventing the actuator post 520 from moving in the +/- X
direction. The interference zones 804a of the friction device 802a
will also limit movement of the actuator post 520 in the direction
of actuation of the actuator post 520 (e.g., in the +/- Z
direction), due to the friction applied to the side of the actuator
post 520. When the friction device 802b is fitted into another one
of the holes 522 of the light guide 512, the interference zones
804b of the friction device 802b will limit movement of a
respective actuator post 520 in the +/- Y direction because the
interference zones 804b serve as a physical barrier preventing the
actuator post 520 from moving in the +/- Y direction. The
interference zones 804b of the friction device 802b will also limit
movement of the actuator post 520 in the direction of actuation of
the actuator post 520 (e.g., in the +/- Z direction), due to the
friction applied to the side of the actuator post 520. Since, in
this embodiment, the keypad portion 510 is a single FIP or IMD
keypad, the overall effect of using at least one friction device
802a and at least one friction device 802b in the holes 522 is to
significantly limit any movement of the keypad portion 510 in the
X, Y, and Z directions. A user pushing the top of a key 518 in the
direction of actuation of the key 518 will still be able to depress
the respective electrical switch 516 by exerting enough force to
overcome the friction applied to the side of the respective
actuator post 520 and the actuation force needed to depress the
respective electrical switch 516 (e.g., either 1.0, 1.35, or 1.6N,
in some examples).
[0061] In another embodiment, FIG. 8a shows interference zones 806,
individually indicated as 806a and 806b. In this example, the
friction device is not formed in the shape of a grommet. Rather,
the interference zones 806 are separately formed as two elongated
members 806a and two elongated members 806b, a perspective view of
which was shown as friction device 530 in FIG. 6. The elongated
members 806a and 806b are then placed on the inside circumference
of the holes 522, for example either moulded into the holes 522 or
attached in the holes 522 using an adhesive. The elongated members
806 may be of any length, less than or equal to the axial length of
the holes 522. In one example, the axial length of the holes 522
may be approximately equal to the thickness of the light guide 512.
The elongated members 806 operate substantially in the same manner
as described above in connection with the interference zones 804.
The elongated members 806 have the advantage of being lighter than
the friction devices 802, an important consideration in the
construction of the portable wireless device 102.
[0062] Referring next to FIG. 8b, four friction devices 810,
individually indicated as 810a, 810b, 810c, and 810d, are shown.
The friction devices 810, in the depicted example, may also be
referred to as grommets. The friction devices 810a, 810b, 810c, and
810d each have one interference zone 812a, 812b, 812c, and 812d,
respectively. Therefore, the friction devices 810 differ from the
friction devices 802 principally in the number of interference
zones that exist. The friction devices 810a, 810b, 810c, and 810d
are generally the same, although each is rotated ninety degrees
with respect to the next, to show how the friction devices 810
would be installed in the holes 522. For example, whereas friction
device 810a would limit movement of a respective actuator post 520
in the -X direction, the friction device 810c would limit movement
of a respective actuator post 520 in the +X direction. Similarly,
whereas friction device 810b would limit movement of a respective
actuator post 520 in the +Y direction, the friction device 810d
would limit movement of a respective actuator post 520 in the -Y
direction. As mentioned earlier, one of the objectives of the
design of the friction devices 810 may be to apply some friction to
the sides of the actuator posts 520, but limited to an amount of
friction that is needed to substantially reduce unwanted vibration
of the keypad portion 510 without adversely affecting the tactility
of the keys 518. With each additional interference zone 812 that is
added to a particular friction device 810, the potential for
reduced tactility of the key 518 to which the associated actuator
post 520 is connected increases. However, in some embodiments, the
keypad portion 510 is a single FIP or IMD keypad. Therefore, in
some embodiments, it may be desirable to reduce the number of
interference zones 812 of each friction device 810, but use more
friction devices 810 in the light guide 512. Therefore, in some
applications, the friction devices 810 may represent an improvement
over the friction devices 802.
[0063] For Example, the friction device 810a shows one interference
zone 812a positioned in the horizontal direction of the FIG. 8b
(e.g., limiting motion of a respective actuator post 520 in the -X
direction). The friction device 810b shows one interference zone
812b positioned in the vertical direction of FIG. 8b (e.g.,
limiting motion of a respective actuator post 520 in the +Y
direction). The friction device 810c shows one interference zone
812c positioned in the horizontal direction of FIG. 8b (e.g.,
limiting motion of a respective actuator post 520 in the +X
direction). The friction device 810d shows one interference zone
812d positioned in the vertical direction of FIG. 8b (e.g.,
limiting motion of a respective actuator post 520 in the -Y
direction). When the friction device 810a is fitted into one of the
holes 522 of the light guide 512, the interference zone 812a of the
friction device 810a will limit movement of a respective actuator
post 520 in the -X direction because the interference zone 812a
serves as a physical barrier preventing the actuator post 520 from
moving in the -X direction. The interference zone 812a of the
friction device 810a will also limit movement of the respective
actuator post 520 in the direction of actuation of the actuator
post 520 (e.g., in the +/-Z direction), due to the friction applied
to the side of the actuator post 520. Similarly, when the friction
device 810b is fitted into another one of the holes 522 of the
light guide 512, the interference zone 812b of the friction device
810b will limit movement of the respective actuator post 520 in the
+Y direction because the interference zone 812b serves as a
physical barrier preventing the actuator post 520 from moving in
the +Y direction. The interference zone 812b of the friction device
810b will also limit movement of the actuator post 520 in the
direction of actuation of the actuator post 520 (e.g., in the +/-Z
direction), due to the friction applied to the side of the actuator
post 520.
[0064] Similarly, when the friction device 810c is fitted into one
of the holes 522 of the light guide 512, the interference zone 812c
of the friction device 810c will limit movement of a respective
actuator post 520 in the +X direction because the interference zone
812c serves as a physical barrier preventing the actuator post 520
from moving in the +X direction. The interference zone 812c of the
friction device 810c will also limit movement of the respective
actuator post 520 in the direction of actuation of the actuator
post 520 (e.g., in the +/-Z direction), due to the friction applied
to the side of the actuator post 520. When the friction device 810d
is fitted into another one of the holes 522 of the light guide 512,
the interference zone 812d of the friction device 810d will limit
movement of the respective actuator post 520 in the -Y direction
because the interference zone 812d serves as a physical barrier
preventing the actuator post 520 from moving in the -Y direction.
The interference zone 812d of the friction device 810d will also
limit movement of the actuator post 520 in the direction of
actuation of the actuator post 520 (e.g., in the +/-Z direction),
due to the friction applied to the side of the actuator post 520.
Since, in this embodiment, the keypad portion 510 is a single FIP
or IMD keypad, the overall effect of using at least one of each of
the friction devices 810a, 810b, 810c, and 810d in the holes 522 is
to significantly limit any movement of the keypad portion 510 in
the +/- X, +/- Y, and +/-Z directions. Of course, a user pushing
the top of a key 518 in the direction of actuation of the key 518
will still be able to depress the respective electrical switch 516
by exerting enough force to overcome the friction applied to the
side of the respective actuator post 520 and the actuation force
needed to depress the respective switch (e.g., either 1.0, 1.35, or
1.6N, in some examples).
[0065] In another embodiment, FIG. 8b shows interference zones 814,
individually indicated as 814a, 814b, 814c, and 814d. In this
example, the interference device is not formed in the shape of a
grommet. Rather, the interference zones 814 are separately formed
as elongated members 814a, 814b, 814c, and 814d. The elongated
members are then placed on the inside circumference of the holes
522, for example either moulded into the holes 522 or attached in
the holes 522 using an adhesive. The elongated members 814 may be
of any length equal to or less than the axial length of the holes
522. In one example, the axial length of the holes 522 may be
approximately equal to the thickness of the light guide 512. The
elongated members 814 are arranged and operate in a similar manner
as was described above in connection with the interference zones
812. The elongated members 814 have the advantage of being lighter
than the friction devices 810, an important consideration in the
construction of the portable wireless device 102.
[0066] The embodiments of the present disclosure described above
are intended to be examples only. Those of skill in the art may
effect alterations, modifications and variations to the particular
embodiments without departing from the intended scope of the
present disclosure. In particular, selected features from one or
more of the above-described embodiments may be combined to create
alternative embodiments not explicitly described, features suitable
for such combinations being readily apparent to persons skilled in
the art. The subject matter described herein in the recited claims
intends to cover and embrace all suitable changes in
technology.
* * * * *