Patent Publication Number: US-2006012563-A1

Title: Rotatable input device for a mobile communication device

Description:
FIELD OF THE APPLICATION  
      The present application relates generally to mobile communication devices. More particularly, the present application relates to an input device for such mobile devices.  
     BACKGROUND OF THE APPLICATION  
      Mobile devices that include a combined text-entry keyboard and a telephone keypad are known. Examples of such mobile devices include cellular telephones, wireless personal digital assistants (PDAs), two-way messaging devices and others. Some mobile devices provide the capabilities to combine a cellular telephone, a two-way messaging device and a PDA. A few mobile devices involve keyboard arrangements and combination of a text entry keyboard (e.g. QWERTY-style keyboard) with a telephone keypad provided on the same mobile device. Ergonomic comfort and how to conduct fast and accurate text entry for e-mail, messaging, notes and other applications, as well as ease of use for telephone, are main concerns.  
       FIGS. 1   a  and  1   b  illustrate a known mobile device  100  featuring an input device  114  capable of providing a keyboard  130  and keypad  126 .  FIG. 1   a  shows device  114  in a closed telephone position whereat keypad  126  is manipulable. Hinge  110  segments the input device  114  to enable the keypad  126  to flip out to the left and reveal the keyboard  130 .  FIG. 1   b  illustrates the mobile device  100  with the keypad  126  flipped out so that input device  114  is in an open text entry position whereat keyboard  130  is manipulable. The keyboard  130  is split into two portions by the hinge  110 , whereby the first portion is integral to the mobile device  100  and the second portion is provided on the part that flips out.  
       FIG. 2  shows a known mobile device  200  featuring a flip out keyboard  214 . The keyboard  214  is attached to the main body of the mobile device  200  with hinge  210 .  
      It may be awkward to do text entry with either of the keyboards shown in  FIGS. 1 and 2 . Furthermore, the keyboard shown in  FIG. 2  may not be an acceptable solution as a telephone.  
     SUMMARY OF THE APPLICATION  
      It is an object of the present application to obviate or mitigate at least one disadvantage of existing input devices used with mobile devices.  
      It is a further object to provide flexibility in the manipulation of keyboards and keypads used with mobile devices.  
      In a first aspect, the present application provides an input device for a mobile device comprising a telephone keypad arranged on one side of the input device for providing an input signal corresponding to at least one telephone character, a keyboard arranged on the opposite side of the input device for providing an input signal corresponding to at least one text character, a connector for attaching the input device to the mobile device for rotating between a first position of the input device and a second position of the input device around a rotation axis. The telephone keypad is operable when the input device is in the first position, and the keyboard is operable when the input device is in the second position.  
      In a second aspect, the present application provides a mobile device comprising of an input device having a telephone keypad arranged on one side of the input device attached to the mobile device for providing an input signal corresponding to at least one telephone character, a keyboard arranged on the opposite side of the input device for providing an input signal corresponding to at least one text character, and a connector for attaching the input device to the mobile device for rotating between a first position of the input device and a second position of the input device around a rotation axis, a microprocessor, operatively connected to the input device for determining the position of the input device and enabling the telephone keypad operable when in the first position and the keyboard operable when in the second position, and receiving the input signal from the input device, and for controlling the operation of the mobile device, and an application module, executable by the microprocessor, for providing a plurality of operational features and initiating such features upon certain inputs from the input device.  
      In preferred embodiments, the input device positions are provided such that the proper balance and ergonomics is achieved. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Embodiments of the present application will now be described, by way of example only, with reference to the attached figures, wherein:  
       FIG. 1   a  illustrates a known mobile device with a flip out input device shown in a telephone keypad position;  
       FIG. 1   b  illustrates a known mobile device with a flip out input device shown in a text entry position;  
       FIG. 2  illustrates a known mobile device with a flip out keyboard;  
       FIG. 3  is a block diagram of a mobile communication device to which the present application may be applied;  
       FIG. 4   a  is an oblique view of a mobile device with a flip out and rotatable input device shown in a telephone keypad position according to an embodiment of the present application;  
       FIG. 4   b  is an oblique view of the mobile device with the flip out and rotatable input device in a flip out position according to an embodiment of the present application;  
       FIG. 4   c  is an oblique view of the mobile device with the flip out and rotatable input device in a rotation position according to an embodiment of the present application;  
       FIG. 4   d  is an oblique view of the mobile device with the flip out and rotatable input device shown in a text entry keyboard position according to an embodiment of the present application;  
       FIG. 5   a  is an oblique view of a touch-screen mobile device with a flip out and rotatable input device shown in a telephone keypad position according to a further embodiment of the present application;  
       FIG. 5   b  is an oblique view of the touch-screen mobile device with the flip out and rotatable input device in a flip out position according to a further embodiment of the present application;  
       FIG. 5   c  is an oblique view of the touch-screen mobile device with the flip out and rotatable input device in a rotation position according to a further embodiment of the present application;  
       FIG. 5   d  is an oblique view of the touch-screen mobile device with the flip out and rotatable input device shown in a text entry keyboard position according to a further embodiment of the present application;  
       FIG. 6  is an outline of an exemplary 2-axis hinge used with the flip out and rotatable input devices for mobile devices according to the present application;  
       FIG. 7  is an exemplary QWERTY keyboard layout used with the mobile device according to present application;  
       FIG. 8   a  is an oblique view of a mobile device with a rotatable input device shown in a telephone keypad position according to a further embodiment of the present application;  
       FIG. 8   b  is an oblique view of the mobile device with the rotatable input device shown in a rotation position according to a further embodiment of the present application;  
       FIG. 8   c  is an oblique view of the mobile device with the rotatable input device shown in a text entry keyboard position according to a further embodiment of the present application. 
    
    
     DETAILED DESCRIPTION  
      Referring now to the drawings,  FIG. 3  is a block diagram of a mobile communication device  300  to which the subject matter of the present application may be applied. The mobile communication device  300  is preferably a two-way communication device having at least voice and data communication capabilities. The device preferably has the capability to communicate with other computer systems on the Internet. Depending on the functionality provided by the device, the device may be referred to as a data messaging device, a two-way pager, a cellular telephone with data messaging capabilities, a cellular telephone with two-way messaging capabilities and personal digital assistant capabilities, personal digital assistant, a wireless Internet appliance or a data communication device.  
      Where the device  300  is enabled for two-way communications, the device will incorporate a communication subsystem  311 , including a receiver  312 , a transmitter  314 , and associated components such as one or more, preferably embedded or internal, antenna elements  316  and  318 , local oscillators  313 , and a processing module such as a digital signal processor (DSP)  320 . As will be apparent to those skilled in the field of communications, the particular design of the communication subsystem  311  will be dependent upon the communication network in which the device is intended to operate. For example, a device  300  destined for a North American market may include a communication subsystem  311  designed to operate within the Mobitex™ mobile communication system, DataTAC™ mobile communication system, or 1X CDMA based data networks, whereas a device  300  intended for use in Europe may incorporate a General Packet Radio Service (GPRS) communication subsystem  311 .  
      Network access requirements will also vary depending upon the type of network  319 . For example, in the Mobitex and DataTAC networks, mobile devices such as device  300  are registered on the network using a unique personal identification number or PIN associated with each device. In GPRS networks however, network access is associated with a subscriber or user of a device  300 . A GPRS device therefore requires a subscriber identity module (not shown), commonly referred to as a SIM card, in order to operate on a GPRS network. Without a SIM card, a GPRS device will not be fully functional. Local or non-network communication functions (if any) may be operable, but the device  300  will be unable to carry out any functions involving communications over network  319 . When required network registration or activation procedures have been completed, a device  300  may send and receive communication signals over the network  319 . Signals received by the antenna  316  through a communication network  319  are input to the receiver  312 , which may perform such common receiver functions as signal amplification, frequency down conversion, filtering, channel selection and the like, and in the example system shown in  FIG. 3 , analog to digital conversion. Analog to digital conversion of a received signal allows more complex communication functions such as demodulation and decoding to be performed in the DSP  320 . In a similar manner, signals to be transmitted are processed, including modulation and encoding for example, by the DSP  320  and input to the transmitter  314  for digital to analog conversion, frequency up conversion, filtering, amplification and transmission over the communication network  319  via the antenna  318 .  
      The DSP  320  not only processes communication signals, but also provides for receiver and transmitter control. For example, the gains applied to communication signals in the receiver  312  and transmitter  314  may be adaptively controlled through automatic gain control algorithms implemented in the DSP  320 .  
      The device  300  preferably includes a microprocessor  338  that controls the overall operation of the device. Communication functions, preferably including at least data and voice communications, are performed through the communication subsystem  311 . The microprocessor  338  also interacts with further device subsystems such as the display  322 , flash memory  324 , random access memory (RAM)  326 , auxiliary input/output (I/O) subsystems  328 , serial port  330 , input device  332 , speaker  334 , microphone  336 , a short-range communications subsystem  340  and any other device subsystems generally designated as  342 .  
      Some of the subsystems shown in  FIG. 3  perform communication-related functions, whereas other subsystems may provide “resident” or on-device functions. Notably, some subsystems, such as input device  332  according to the present application and display  322  for example, may be used for both communication-related functions, such as making a telephone call and entering a text message for transmission over a communication network, and device-resident functions such as a calculator or task list.  
      Operating system software used by the microprocessor  338  is preferably stored in a persistent store such as flash memory  324 , which may instead be a read only memory (ROM) or similar storage element (not shown). 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 RAM  326 . It is contemplated that received communication signals may also be stored to RAM  326 .  
      The microprocessor  338 , in addition to its operating system functions, preferably enables execution of software applications on the device. A predetermined set of applications which control basic device operations, including data and voice communication applications for example, will normally be installed on the device  300  during manufacture. A preferred application that may be loaded onto the device may be a personal information manager (PIM) application having the ability to organize and manage data items relating to the device user such as, but not limited to e-mail, calendar events, voice mails, appointments, and task items. Naturally, one or more memory stores would be available on the device to facilitate storage of PIM data items on the device. Such PIM application would preferably have the ability to send and receive data items, via the wireless network. In a preferred embodiment, the PIM data items are seamlessly integrated, synchronized and updated, via the wireless network, with the device user&#39;s corresponding data items stored or associated with a host computer system thereby creating a mirrored host computer on the mobile device with respect to the data items at least. This would be especially advantageous in the case where the host computer system is the mobile device user&#39;s office computer system. Further applications may also be loaded onto the device  300  through the network  319 , an auxiliary I/O subsystem  328 , serial port  330 , short-range communications subsystem  340  or any other suitable subsystem  342 , and installed by a user in the RAM  326  or preferably a non-volatile store (not shown) for execution by the microprocessor  338 . Such flexibility in application installation increases the functionality of the device 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 device  300 .  
      In a data communication mode, a received signal such as a text message or web page download will be processed by the communication subsystem  311  and input to the microprocessor  338 , which will preferably further process the received signal for output to the display  322 , or alternatively to an auxiliary I/O device  328 . A user of device  300  may also compose data items such as email messages for example, using the input device  332  according to the present application, which is a complete alphanumeric keyboard on one side and a telephone-type keypad on the opposite side, in conjunction with the display  322  and possibly an auxiliary I/O device  328 . Such composed items may then be transmitted over a communication network through the communication subsystem  311 .  
      For voice communications, overall operation of the device  300  is substantially similar, except that received signals would preferably be output to a speaker  334  and signals for transmission would be generated by a microphone  336 . Alternative voice or audio I/O subsystems such as a voice message recording subsystem may also be implemented on the device  300 . Although voice or audio signal output is preferably accomplished primarily through the speaker  334 , the display  322  may also be used to provide an indication of the identity of a calling party, the duration of a voice call, or other voice call related information for example.  
      The serial port  330  in  FIG. 3  would normally be implemented in a personal digital assistant (PDA)-type communication device for which synchronization with a user&#39;s desktop computer (not shown) may be desirable, but is an optional device component. Such a port  330  would enable a user to set preferences through an external device or software application and would extend the capabilities of the device by providing for information or software downloads to the device  300  other than through a wireless communication network. The alternate download path may for example be used to load an encryption key onto the device through a direct and thus reliable and trusted connection to thereby enable secure device communication.  
      A short-range communications subsystem  340  is a further optional component which may provide for communication between the device and different systems or devices, which need not necessarily be similar devices. For example, the subsystem  340  may include an infrared device and associated circuits and components or a Bluetooth™ communication module to provide for communication with similarly enabled systems and devices.  
      Thus, it will be apparent that mobile devices of this type perform a wide variety of complex functions and it is a challenge to provide an input device which is sufficiently compact to match the form factor of the handheld device but which provides the necessary level of functionality required by the user.  
       FIG. 4   a  is an oblique view of a mobile device  400  with a flip out and rotatable input device  414  shown in a telephone keypad position according to an embodiment of the present application. The input device  414  is mounted to the mobile device  400  by a connector  410  such as a 2-axis hinge. One side of the input device  414  is a telephone keypad, and the opposite side of the input device  414  is a text entry keyboard such as a QWERTY keyboard. As shown in  FIG. 4   a , the input device  414  sits on the main body  404  of the mobile device  400  so that a telephone keypad  426  faces up. In this position, the telephone keypad  426  is activated and the mobile device  400  provides telephone-related functions. The telephone keypad  426  includes four rows of three buttons. The first three rows are typically formed from the numbers 1-9, arranged left to right, top to bottom, in an increasing order. The fourth row is formed from the keys ‘*’ ‘0’ and ‘#’. Alphabetic values are ascribed to keys 2-9 in a standardized alphabetic order. Although not expressly shown in the drawing, it is envisaged that SEND and END keys or other such inputs typical in telephony can also be provided in combination with the telephony keypad. In this telephony position, the input device  414  maintains a firm contact with main body  404  of the mobile device  400  so as to provide a good balance while it is used to enter telephony input. The user can perform fast and exact dialing by manipulating the telephony keypad  426 .  
      When the telephone keypad  426  faces up, the mobile device  400  may display a user interface including telephone-related applications or functions on a screen  418 . An auxiliary input device such as a thumbwheel  416  is used to navigate on the screen such as moving a cursor on the screen  418  to select an application like checking voice-mail and other menu-based functions. When a call is incoming, the screen  418  displays the options “answer call” and “ignore call”. The thumbwheel  416  is used to select one option and handle the incoming telephone call. An escape key  412  may be pressed to hang up a telephone call.  
      In this embodiment, the connector  410  is a 2-axis hinge as shown in  FIG. 6 . The hinge comprises a first axis and a second axis. The first axis is perpendicular to the second axis. The input device turns around the first axis to flip open from main body of the mobile device, and rotates around the second axis, and then flips back onto the main body of the mobile device to reveal the QWERTY keyboard for text entry. There are many options for the connector, which are known to those of skill in the art.  
       FIG. 4   b  is an oblique view of the mobile device  400  with the flip out and rotatable input device  414  in a flip out position according to an embodiment of the present application. The input device  414  is flipped up around a first axis or a flip axis for flipping and then rotated in a clock-wise direction or in a counter-clockwise direction around a second axis or rotation axis.  FIG. 4   c  shows an oblique view of the mobile device  400  with the flip out and rotatable input device  414  in a rotation position according to an embodiment of the present application. The first axis is perpendicular to the second axis.  
       FIG. 4   d  is an oblique view of the mobile device  400  with the flip out and rotatable input device  414  shown in a text entry keyboard position according to an embodiment of the present application. The input device  414  is flipped back in place and faced up after a process of flip out and rotation as shown in  FIG. 4   b  and  FIG. 4   c . In this keyboard position, the input device  414  maintains a firm contact with main body  404  of the mobile device  400  so as to provide a good balance while it is used to enter text characters. The user can perform fast and exact text entry by manipulating the QWERTY keyboard.  
      When the QWERTY keyboard  430  faces up, correspondingly the keyboard  430  is activated, and the mobile device  400  can display a user interface including data-related applications and functions such as email-related functions, taking notes, Internet access, calendar, to-do list and others. The thumbwheel  416  is rotated to navigate on the screen  418  for data-related functions. For example, causing a cursor to move in order to select and perform a function. The escape key  412  can be pressed for exiting a function.  
      When a QWERTY keyboard  430  faces up, an incoming call can still be picked up, as can an outgoing call be made. For incoming calls, the screen  418  displays the options “answer call” and “ignore call”, whereas for outgoing calls the keyboard  430  can be used for number dialing or for dial by name. Similarly, when the telephone keypad  426  faces up, an email can be checked by manipulating the thumbwheel  416 .  
      Preferably, the QWERTY keyboard  430  is a thumb keyboard so as to provide greater ergonomic comfort to a user when entering text. Text-entry characters could alternatively be arranged in other keyboard patterns, such as a DVORAK style keyboard, an alphabetic style keyboard, a QWERTZ style keyboard, an AZERTY style keyboard, or the like.  
      The mobile device  400  preferably displays a telephone-related user interface when the telephone keypad  426  faces up, and a text-entry related user interface when the QWERTY keyboard  430  faces up. Those of skill in the art can appreciate that a variety of sensing means, such as induction, opto-mechanical, or electro-mechanical contacts, may be used to determine which of keypad  426  or keyboard  430  faces up. The keypad  426  or keyboard  430  facing up is activated, and receives key input from the keypad or keyboard activated. The other one facing down is deactivated, and key input from it is not available. Alternatively, the mobile device  400  may display a user interface including telephone-related functions and data-related functions whenever the telephone keypad  426  or the QWERTY keyboard  430  is facing up.  
      In the embodiment, each key corresponds to one or more alphabetic characters, or corresponds to one or more alphanumeric characters as shown in  FIG. 7  so that the numbers of keys may be reduced and the mobile device  400  can be more compact. The input device  414  may also include other non-alphanumeric, or command, keys such as a symbol key  442 . Such a key may access symbols or alternative functions when depressed in conjunction with the depression of another key or an auxiliary input such as the thumbwheel  416 . A command key  434  is provided to access upper case letters when this command key  434  and a key with an upper letter are depressed in sequence. For example, if a user intends to input character “W”, the user just presses a key  438  whereat if a user intends to input number “1”, the user press the command key  434  and then press the key  438 .  
      Alternatively, when the input device  414  is in a text entry position, the mobile device  400  can perform telephone functions. For example, by manipulation of the thumbwheel  416 , the telephone functions displayed on the screen  418  can be selected. The input device  414  can be used to input telephone characters.  
      Depending on the user&#39;s preference and telephone use frequency, the user can set the telephone keypad of the input device  414  to face up normally. Since keys of the telephone keypad are bigger than keys of the keyboard, and since the telephone keypad layout is familiar to most users, it is advantageous to use the telephone keypad to make telephone calls.  
      According to present application, the keyboard of the mobile device can be used flexibly by changing keyboard positions around a 2-axis hinge between a telephone keypad and a text entry keyboard to meet different user&#39;s needs, and it makes use of the mobile device more interesting for users.  
      Alternatively, instead of a thumbwheel  418  and an escape key  412  on the side of the mobile device, a navigation key for navigating on a screen, and a key for picking up and hanging up telephone calls and exiting function may be arranged on the surface of the mobile device between the screen and the input device, the keypad, or the keyboard.  
       FIG. 5   a  is an oblique view of a mobile device  500  with a flip out and rotatable input device  514  shown in a telephone keypad position according to a further embodiment of the present application. The mobile device  500  is provided with a touch screen  518 . The touch screen  518  may be a touch sensitive liquid crystal display screen. A touch pad may be displayed on the lower portion of the screen  518  which can be covered by the input device  514 . When a user intends to use the touch pad to input alphabetic characters, he/she may flip out the input device  514  to make the screen  518  bigger. The input device  514  can be flipped out 180° to provide greater ergonomic comfort to the user when the touch pad is used. As shown in  FIG. 5   b , the input device  514  is in a flip out position. The input device  514  is an outer optional input which can be used to input telephone characters or text characters instead of the touch pad. Under this input device position, the keypad maintains a good balance for telephony signaling because it sits on and is supported by the main body  504  of the mobile device  500 . The user is provided greater ergonomic comfort, and can perform fast and exact telephony signaling.  
      The input device  514  is mounted to the mobile device  500  by a connector  510  such as a 2-axis hinge. One side of the input device  514  is a telephone keypad, and the opposite side of the input device  514  is a QWERTY keyboard. When the input device  514  is in a position as shown in  FIG. 5   a , the input device  514  sits on the main body  504  of the mobile device  500 , and a telephone keypad  526  is exposed and activated for entering telephone signals, and the mobile device  500  preferably provides telephone-related functions. The telephone keypad  526  is similar to that of  FIG. 4   a.    
      The connector  510  may be a 2-axis hinge including a first axis or a flip axis and a second axis or a rotating axis as shown in  FIG. 6 . By means of the flip axis, the input device can be opened. When a user intends to do text entry, he/she flips out the input device  514  as shown in  FIG. 5   b , and rotates it in a direction by means of the second axis as shown in  FIG. 5   c , and then flips the input device  514  back to reveal a QWERTY keyboard  530 .  
       FIG. 5   d  shows an oblique view of the mobile device  500  with the flip out and rotatable input device  514  shown in a text entry keyboard position according to a further embodiment of the present application. Under this input device position, the text entry keyboard is activated and the telephone keypad may be deactivated. The keyboard maintains a good balance for text entry because it sits on and is supported by the main body  504  of the mobile device  500 . The user is provided greater ergonomic comfort, and can perform fast and exact text-entry.  
      The mobile device  500  may display options about telephone-related functions such as telephone characters entry, sending and receiving telephone calls, and options about text-entry related functions such as composing, sending, and receiving email, taking notes and others on the screen  518 .  
      Similarly to  FIG. 4   a - FIG. 4   d , when the QWERTY keyboard  530  faces up, an incoming call still can be picked up by manipulating thumbwheel  516 , or by other means. When the telephone keypad  526  faces up, an email still can be checked by means of the thumbwheel  516 , or by other means.  
      The telephone keypad  526 , the QWERTY keyboard  530 , the thumbwheel  516 , an escape key  512 , and a command key  534  are all similar to those of  FIG. 4   a - 4   d  in structures and functions. The text-entry keyboard  530  may be styled as a QWERT keyboard, a DVORAK keyboard, an alphabetic style keyboard, a QWERTZ style keyboard, a AZERTY style keyboard, and the like.  
      Alternatively, when the input device  514  is in a QWERTY position, the mobile device  500  can send telephone calls via manipulation of the thumbwheel  516  to select a telephone function displayed on the screen  518 , or by manipulation of the keyboard  530  to type the name of a contact, or by pressing a key of keyboard  530  to utilize each key as a speed dial. The input device  514  can be used to input telephone characters as well, for example for number dialing, or to dial by name. In  FIG. 5   d , a command key  534  and an alphanumeric key  538  are all similar to the keys  434  and  438  in  FIG. 4   d.    
      In a further embodiment, an input device with a telephone pad on one side and a text entry keyboard on the opposite side is detachable with the main body of a mobile device. The input device may plug into the main body of the mobile device, and a user can use the telephone keypad or the text entry keyboard by rotating the input device around a connection axis to face up and activate the telephone keypad or the text entry keyboard. The mobile device is preferably a touch screen mobile device or a hand writing mobile device, and the input device can be used as an extra input device under this circumstance.  
       FIG. 6  illustrates an outline of an exemplary 2-axis hinge used with the flip out and rotatable input device for a mobile device according to the present application. It includes a flip axis  615 , a rotation axis  619  and a main body  610 . The input device is opened around the flip axis  615 , and then rotated around the rotation axis  619  to reveal the telephone keypad for telephone functions or the QWERTY keyboard for text-entry and Internet access. The input device can be changed flexibly between the telephone keypad and the QWERTY keyboard. The 2-axis hinge shown  FIG. 6  is only an example. There are other forms for it. For example, it can include a first part such as a single axis hinge, and a second part mounted to the first part perpendicularly. There are many hinges with different structures that can be used with the keyboards of the present application. Although  FIG. 6  shows one exemplary 2-axis hinge unit, the use of other 2-axis hinge units is envisaged, such as the Flexible type ST1231 hinge unit from Strawberry Corporation of Japan. According to the manufacturer&#39;s web site, “ . . . this hinge unit is best suited for devices such as Camera Phones or Mobile Phones with TV attached. In such applications the user can view the display without opening the device. This type of hinge unit is also known as nail-cutter type hinge.” 
      Further the person skilled in the art will appreciate that the keys on the keyboard and keypads can be combined to provide various layouts. For example,  FIG. 7  shows an exemplary keyboard layout  714  used with the mobile device according to the present application. Some of keys include two text entry characters, and some of the keys include three numerical and text entry characters. For instance, a key  738  includes two associated text-entry characters “Q” and “W”, and a key  742  includes number “1” and two associated text-entry characters “E” and “R”. A command key  734  is used to toggle input on the three-character keys such as the key  742  between the numbers and the text entry characters. When the function key  734  and the key  742  is pressed in sequence, number “1” is input. For two-character key such as the key  738 , if the left-hand portion of the key  738  is pressed, then the text entry character “Q” is input. If the right-hand portion of the key  738  is pressed, then the text entry character “W” is input. For three-character keys such as a key  742 , their input is similar to those two-character keys when the function key  734  is not pressed. Alternatively, the mobile device may employ some predictive text software application in order to deduce what a user is spelling. For example, if the user were to depress the key  738 , the software would determine whether the user intends to enter a “Q”, or “W”. Predictive text software applications are typically executed by a keystroke interpreter which receives signals generated by the depressing of either the alphanumeric or the non-alphanumeric keys and maps the received signals into a sequence of alphanumeric or the non-alphanumeric values.  
      A symbol key  742  provides various symbols including “.”, “,”, “;”, “″”, “′”, “:”, “?”, “/”, “&gt;”, “&lt;”, “!”, “@”, “˜”, “$”, “%”, “ˆ”, “&amp;”, “(”, “)”, “_”, “−”, “+”, “=”, “[”, “]”, “{”, “}”, “|”, and “\”, among other known symbols.  
      Other keyboard layouts may also be provided. For example, some of the keys may have three associated text entry characters.  
       FIGS. 8   a - 8   b  show a mobile device  800  with a rotatable input device  814  according to a further embodiment of the present application. The input device  814  is mounted to the mobile device  800  by a connector  810  such as an axis. One side of the input device  814  is a telephone keypad  826  as shown in  FIG. 8   a , and the opposite side of the input device  814  is a text-entry keyboard  830  such as a QWERTY keyboard as shown in  FIG. 8   c . The mobile device provides telephone-related functions when the telephone keypad  826  faces up and is correspondingly activated, and provides text-entry related functions when the text-entry keyboard  830  faces up and is correspondingly activated. A display  818  can display a user interface as described in  FIGS. 4   a - 4   d  and  5   a - 5   d.    
       FIG. 8   b  shows the mobile device  800  with the rotatable input device  814  in a rotation position. By rotating the input device  814 , the telephone keypad  826  and the text-entry keyboard  830  face up alternatively for a user to use them.  
      Those of skill in the art will appreciate that a variety of sensing means, such as induction, opto-mechanical, or electro-mechanical contacts, may be used to determine which of keypad  826  or keyboard  830  faces up. For example, a sensing mean such as a electro-mechanical contact can be connected to the connector  810 . By detecting a change of its position, a microprocessor of the mobile device  800  determines which of keypad  826  or keyboard  830  faces up, and correspondingly enable the keypad  826  or keyboard  830  facing up to receive key input, and disable the other one facing down to make key input unavailable.  
      Other aspects of this embodiment including a command key  834 , an alphanumeric key  838 , a thumbwheel  816 , and an escape key  812  are all similar to those of the mobile devices in  FIGS. 4   a - 4   d  and  FIGS. 5   a - 5   d . They are not described further herein.  
      The above-described embodiments of the present application are intended to be examples only. Alternations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the application, which is defined solely by the claims appended hereto.