Patent Publication Number: US-2007111750-A1

Title: Mobile communication terminal with multi orientation user interface

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S)  
      This application claims the benefit of U.S. application Ser. No. 10/690,934 filed 22 Oct. 2003 incorporated by reference herein in its entirety.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to mobile communication terminals comprising a user interface with a display and a keypad for supporting various functions and in particular facilitating user interaction with different functionalities associated with mobile communication terminals.  
      2. Brief Description of Related Developments  
      Mobile communication terminals such as mobile phones or personal digital assistants (PDA) generally have a layout with a front surface provided with a screen in the upper part and a keypad there below. As mobile communication terminals have become increasingly complex, a great number of additional features have been included, giving users an increased number of ways to use their mobile communication terminal. For some of these functions, the traditional layout described earlier is appropriate, but for another group of functions a different layout would be preferable. Prior art terminals have however not provided a terminal with a more flexible layout, though several attempts have been made to allow these terminals to be used in different orientations:  
      US 2003/0073462 discloses a mobile terminal in which the orientation of the information on the display can be changed, so that the terminal can be used in an upright position and in a horizontal position. The keys of the keypad are however not labeled so that the user has to memorize the function(s) of the individual keys. Memorizing the functions of all the keys causes a steep learning curve, and in turn to a reduced user acceptance of this type of terminal.  
      WO 02/47365 discloses a mobile communication terminal with a user interface that can be used in a layout with a front surface provided with a screen in the upper part and a keypad there below. The orientation of the information shown on the display can be changed. The keypad as a whole is arranged on a disk that is rotatable relative to the housing of the mobile terminal with wire leads running through the central pivot point connecting the disk to the housing. The terminal can thus be used in different orientations, e.g. upside down with the keypad above the display. The rotatable keypad arrangement is however mechanically complicated and sensitive. Problems with twisting leads have also been observed. This is undesirable since mobile terminals need to be rugged and robust to endure the influences that they are exposed to during mobile use.  
      Thus, none of the prior art solutions have been quite satisfactory, since either the labels were absent, or the readability of the labels of the keys was difficult when the device is not used in its standard orientation or the means for changing the label orientation were sensitive mechanisms with complex mechanical and/or electro-mechanical features.  
     SUMMARY OF THE INVENTION  
      On this background, it is an object of the present invention to provide a mobile communication terminal of the kind referred to initially, with a flexible, robust and user friendly user interface.  
      This object is achieved in accordance with claim  1  by providing a mobile communication terminal having a user interface comprising a display for showing information and a keypad including at least one softkey. The function of the softkey is controlled by a controller unit and displayed as a soft label in a predetermined area of said display. The terminal is further provided with means for instructing the controller unit to change the orientation of the soft label.  
      When using the mobile terminal an orientation other than the standard orientation the readability of the labels is a problem (unless the user is trained to read tests upside down or sideways). This is particularly true for the softkeys since their function can due to their changing nature and contrary to e.g. the alphanumerical hard keys not be memorized. By allowing the orientation of the label in the predetermined area to the changed a better user interface is obtained when the terminal is not in the standard orientation. The orientation of the soft label is changed without changing the position of the predetermined area relative to the at least one softkey so that the any physical proximity there between is maintained.  
      The controller unit may change the orientation of the soft label in response to a state change of the terminal or a upon a user entered command.  
      Alternatively, an orientation sensor in the terminal or a manually activated switch can be used to prompt the controller unit to change the orientation of the soft label.  
      The same orientation changes can be applied to information on the display as to the soft label. Because the softlabel should not change place, the layout of the display will change.  
      The above object is also achieved by a mobile communication terminal having a user interface comprising a display for showing information and a keypad including at least one hard key with a hard label that can be read in at least two different orientations. The present function of the at least one hard key is controlled by a controller unit in dependence of the orientation of the terminal. Means are provided for informing the controller unit of the orientation of the terminal.  
      The orientation of the information on the display is preferably changed in accordance with the orientation of the terminal.  
      The combination of a multidirectionally labeled key and a display that can adapt the orientation of the information shown thereon allow the terminal to be used in different orientations.  
      The above object is also achieved by a mobile communication terminal having a user interface comprising a display for showing information and a keypad including a plurality of hard keys. The labels of the hard keys include textual and or graphical content relating to the function of the hard key concerned. The label of least one of the hard keys is formed by a hologram on which the textual and/or graphical content can be read in at least two different orientations.  
      Preferably, the information on the display can be shown in the different orientations in which the hologram label can be read.  
      The above object is also achieved by a mobile communication terminal having a user interface comprising a display for showing information and a keypad including a plurality of hard keys. The labels of the hard keys include textual and or graphical content relating to the function of the hard key concerned. At least one of the hard keys is formed by an at least partially transparent key body that allows objects under the key to be seen through the top of the key. At a substrate that can move relative to the key is provided with at least two labels. The labels include textual and/or graphical content that can preferably be read in different ordinations. The substrate can be moved relative to the hard key to allow a different one of the at least two labels to be visible through the key.  
      The different labels can associated with different functions of the key concerned or to different orientations in which the label can be read. Accordingly, a user can slide the substrate to a position in which the desired labels areas are visible.  
      The substrate may extend under a plurality of keys, so that a group of labels belonging to a plurality of keys can be moved simultaneously. Accordingly, it is possible to have a coherent group of functions for a set of keys visible in one position of the substrate, and another group of functions visible in another position of the substrate.  
      In one embodiment the labels are arranged on a substrate that can slide linearly, in another embodiment slidable the substrate is rotably arranged.  
      The above object is also achieved by a mobile communication terminal having a user interface comprising a display and a keypad including at with a plurality of hard keys. The labels of the hard keys include textual and or graphical content relating to the function of the hard key concerned. At least one of the hard keys comprises a lenticular screen with at least two interlaced labels there behind. Each of the at least two labels being visible from a different viewpoint and preferably being readable in a different orientation.  
      Accordingly, different labels becomes visible from different viewpoints e.g. one label area is visible in the standard orientation and another label area is visible in the upside down orientation.  
      Preferably, the orientation of the information on the display can be changed to be readable in different orientations of the terminal. A set of keys may be provided with labels of which different areas are visible from different viewpoints.  
      Accordingly, a group of coherent functions for the set of keys is visible form one viewpoint and another group of coherent functions is visible from another viewpoint.  
      The above object is also obtained by a mobile communication terminal having a user interface comprising a display and a keypad including a plurality of hard keys. The labels of the hard keys include textual and or graphical content relating to the function of the hard key concerned. At least one of the hard keys is formed by an at least partially transparent key body that allows objects under the key to be seen through the top of the key. A label is arranged under the key on a pair of polarized films that can be moved relative to one another. The textual and/or graphical content of the label can be read in at least two different orientations in dependence of the relative orientation of the polarized films to one another.  
      Accordingly, the label orientation can be changed. Preferably, a handle or other arrangement is provided to rotate the one film relative to the other.  
      The above object is also obtained by a mobile communication terminal having a user interface comprising a display and a keypad including a plurality of hard keys arranged in a substantially circular pattern. The labels of the hard keys include textual and or graphical content relating to the function of the hard key concerned. The hard keys are formed by an at least partially transparent key body that allows objects under the key to be seen through the top of the key. The labels of the hard keys being arranged on a rotatable substrate in a substantial circular pattern that matches the circular pattern in which the hard keys are arranged. Preferably, the labels are arranged on the substrate in different groups. Each group being visible through the plurality of keys in a given position of the substrate. The label may be attached to a handle or other mechanism for rotating the substrate, possible in small angular steps.  
      Accordingly, the user can rotate the substrate until the desired label group is visible. The label groups can relate to different functions and/or different orientations in which the labels can be read  
      The above object is also obtained by a mobile communication terminal having a user interface comprising display, a confirming key and a rejection key. A function to be confirmed or to be rejected is controlled by a controller unit and displayed in a predetermined area of the display. The terminal also comprises means for instructing the controller unit to change the orientation in which the function is displayed. Accordingly, the confirmation key and the rejection key can be used with the terminal in different orientations, whilst the function to be confirmed or rejected is comfortably readable by a user. The terminal can be provided with an orientation sensor that delivers a signal to the controller unit for automatically selecting the appropriate orientation for the function shown in the display. Accordingly, the user can simply turn the terminal in a desired orientation of use and continue using the confirmation and rejection keys without having any problems in reading the associated function in the display.  
      The controller unit changes the orientation of the function to be confirmed or to be rejected preferably without changing the position of the predetermined area relative to the confirming key and rejection key.  
      The controller unit may also change the orientation of the function to be confirmed or to be rejected in response to a state change of the terminal or a upon user entered command.  
      Further objects, features, advantages and properties of the mobile communication terminal according to the invention will become apparent from the detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      In the following detailed portion of the present description, the invention will be explained in more detail with reference to the exemplary embodiments shown in the drawings, in which  
       FIG. 1  illustrates a first embodiment of a mobile communication terminal, for use with the present invention in a standard orientation;  
       FIG. 2  illustrates the terminal of  FIG. 1  in an upside down orientation;  
       FIG. 3  illustrates the terminal of  FIG. 1  in a sideways orientation;  
       FIG. 4  illustrates a second embodiment of a mobile communication terminal for use with the present invention in a standard orientation;  
       FIG. 5  illustrates the terminal of  FIG. 4  in an upside down orientation;  
       FIG. 6  illustrates a third embodiment of the present invention in a standard orientation;  
       FIG. 7  is a block diagram illustrating the general architecture of the mobile terminal of  FIG. 6 ;  
       FIG. 8  illustrates the mobile terminal of  FIG. 6  in an upside down orientation;  
       FIG. 9  illustrates a fourth embodiment of the present invention in a first orientation;  
       FIG. 10  illustrates the mobile terminal of  FIG. 9  in an upside down orientation;  
       FIG. 11  illustrates a fifth embodiment of the present invention in a first orientation;  
       FIG. 12  illustrates in detail a first arrangement to change visible label sections;  
       FIG. 13  illustrates the mobile terminal of  FIG. 11  in a sideways orientation;  
       FIG. 14  illustrates a sixth embodiment of the present invention;  
       FIG. 15  illustrates a variation of the sixth embodiment;  
       FIG. 16  illustrates a seventh embodiment of the present invention in a first orientation with a first set of labels being visible;  
       FIG. 17  illustrates in detail a second arrangement to change visible label groups;  
       FIG. 18  illustrates the mobile terminal of  FIG. 17  with a second label group being visible;  
       FIG. 19  illustrates the mobile terminal of  FIG. 17  with in and upside down orientation with a third label group is visible;  
       FIG. 20  illustrates in detail a third arrangement to change visible label sections;  
       FIG. 21  illustrates in detail a fourth arrangement to change visible label sections;  
      FIGS.  22  to  24  illustrate details of an arrangement to change label orientation;  
       FIG. 25  illustrates in detail a fifth arrangement to change visible label sections; and  
       FIG. 26  illustrates in detail a sixth arrangement to change visible label sections. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)  
      The various features of the invention will now be described with respect to the figures, in which like parts are identified with the same reference numerals.  
       FIG. 1  shows a first preferred embodiment the mobile communication terminal  1  according to the invention in the form of a pager. The pager  1  comprises a user interface having a keypad  2  and a display  3 . The keypad has a group of alpha keys  8  for entering texts and a softkey  9 . The present function of the softkey  9  is shown as text  22  (softkey-label) in a separate field  21  in the display  3  just above the softkey  9 . The softkey  9  is a multifunctional key and its present function depends on the state of the pager  1 . The softkey  9  give access to the menu and functions relating to message handling.  
      The pager is provided with an orientation sensor (not shown) that informs a processor unit (not shown) of the present orientation of the pager. When the signal from the orientation sensor indicates that the pager is in an upside down orientation as illustrated in  FIG. 2  the processor unit changes the orientation of the text  22  in field  21  accordingly. The processor unit changes the orientation of the text in the separate field  21  without changing the location of the separate field  21 . The separate field  21  stays therefore proximate to the softkey  9 . The processor unit may also change the orientation of the other information that is shown on the display  3 .  FIG. 3  illustrates the pager in a sideways orientation.  
       FIG. 4  shows a second preferred embodiment the mobile communication terminal  1  according to the invention in the form of a PDA. The PDA comprises a user interface having a keypad  2  and a display  3 . The keypad has a group of softkeys  9 ′ for entering texts and number and two softkeys for menu access and for selection of menu items. The present function of the softkeys  9 , 9 ′ is shown as text in a separate fields  21  and  23  in the display  3 . The softkeys  9 , 9 ′ are multifunctional keys and their present function depends on the state of the PDA, e.g. in a text editing mode the keys will have alpha functions, in a numerical mode the softkeys  9  will have numerical functions.  
      The PDA is provided with an orientation sensor (not shown) that informs a processor unit (not shown) of the present orientation of the pager. When the signal from the orientation sensor indicates that the pager is in an upside down orientation as illustrated in  FIG. 5  the processor unit changes the orientation of the text in fields  21 , 23  accordingly. The processor unit changes the orientation of the text in the separate fields  21 , 23  without changing the location of the separate fields  21 , 23 . The processor unit may—as shown—also change the orientation of the other information that is shown on the display  3 , however without changing the location of the separate fields  21 , 23 .  
       FIG. 6  illustrates a third embodiment the mobile communication terminal  1  according to the invention in the form of a mobile phone. The mobile phone, shown in the standard upright orientation, comprises a user interface having a keypad  2 , a display  3 , an on/off button (not visible, present in the top of the phone) a speaker  5 , and a microphone  6  (only the opening present in the bottom of the phone is visible). The mobile phone  1  according to the preferred embodiment is adapted for communication via a cellular network, such as the GSM 900/1800 MHz network, but could just as well be adapted for use with a Code Division Multiple Access (CDMA) network or the G3 network.  
      According to a preferred embodiment, the keypad  2  has a first group  8  of keys as alphanumeric keys, a confirm key  9 ″ and a reject key  9 ′″, a cursor navigation key  10  (scroll up/down/left/right), and on-hook and off-hook keys  12 . The present function to be confirmed or rejected is shown as text  22  (the function can alternatively also be shown graphically in the form of e.g. an icon) in separate field  21  in the middle of the lower part of the display  3  near the rejection key  9 ″ and confirming key  9 ′″. The present function to be rejected or confirmed depends on the state of the mobile phone, and the previously selected or rejected functions. The removal of an entry from the phonebook is illustrated in  FIG. 6  by way of example.  
       FIG. 7  illustrates in block diagram form the general architecture of the mobile phone constructed in accordance with the present invention. The mobile phone includes a microprocessor  18  for controlling the operation of the mobile phone, a program memory (flash ROM  17   b ) for storing programs used by the mobile telephone and a random access memory (RAM  17   a ). Input/output circuits interface the microprocessor  18  with a keypad  2 , a display  3 , digital signal processing unit  14 , and the receiver/transmitter circuit  19 . The receiver/transmitter circuit  19  is connected to an internal antenna  15 . The digital signal processing circuit  14  provides analog audio outputs to the speaker  5  and accepts analog audio inputs from the microphone  6 . The processor  18  also forms the interface to the peripheral units of the apparatus, including an orientation sensor  20  and a SIM card  16 , as well as data, power supply, etc.  
      The mobile phone comprises a tilt sensor  20  which determines the direction and magnitude of the rotational displacement relative to vertical using the planetary gravitational field. The sensor preferably measures the rotational changes about two orthogonal axes. The construction of the sensor  20  is not shown but can be of any of well known types such as those operating with accelerometers (taking the gravitational force into accounts when determining acceleration), with encoding disks on a freely rotatable shaft connected to a weight, or of the type that uses sphere provided with an asymmetrical weight that floats in a liquid. Alternatively the tilt sensor  20  could be of the gyroscopic type. Preferably, the sensor is of a miniaturized type, e.g. by using Micro-Electro-Mechanical Systems (MEMS) technology (the integration of mechanical elements, sensors, actuators, and electronics on a common silicon substrate through micro-fabrication technology). If the mobile phone is provided with a digital camera the signal from the camera can be used to support the signal from an absolute type angular sensor, as described in e.g. PCT application PCT/EP 03/00607, hereby incorporated by reference.  
      The signal of the tilt sensor  20  is sent to the processor unit  18 . The processor unit  18  analyzes the signal from the tilt sensor  20  and determines the orientation of the mobile phone. The function to be selected or rejected can be displayed in four discrete orientations: normal, upside down, 90° clockwise and 90° anti-clockwise. The user will not normally hold the mobile phone perfectly upright, upside down, etc. The processor unit  18  selects therefore the display orientation that best matches the measured orientation of the phone.  FIG. 8  illustrates the mobile phone in and upside down orientation with the function to be selected perfectly readable to the user. In  FIG. 8  the display direction of the content of the main area of the display has been reversed.  
      The processor unit is preferably programmed to ignore quick changes in measured orientation in order to avoid inadvertent quick repetitive changes in the display origination of the function to be selected or rejected. The function to the selected or rejected can thus always be easily read by a user in any orientation of the mobile phone.  
      The user may switch off the orientation sensor  20  and control the orientation direction of the function to be selected or rejected via the user interface. This can be advantageous when e.g. traveling in an airplane or train, where the accelerative forces of the moving vehicle could disturb proper operation of the tilt sensor.  
      The user may also instruct the processor through the user interface to apply a 90° offset to the signal from the orientation sensor to compensate for the users present position. Thus, the orientation of the information in the display is also comfortably readable for a user who is using the terminal while laying on the side.  
       FIG. 9  illustrates a fourth preferred embodiment of the mobile communication terminal  1  according to the invention in the form of a mobile phone. The mobile phone, shown in the standard upright orientation, is similar to previously described mobile phone, however the keypad  2  has a first group  8  of keys as alphanumeric keys, two softkeys  9 , a cursor navigation key  10  (scroll up/down), and on-hook and off-hook keys  12 . The present functionality of the softkeys  9  is shown as text  22  in separate fields  21  (softkey-labels) in the display  3  just above the softkeys  9 . The softkeys  9  are multifunction keys and their present function depends on the state of the mobile phone  1 . The softkeys  9  give access to the menu, the phonebook and can activate actions related to call handling and message handling.  
      The mobile phone comprises the same tilt sensor  20  as in the previous embodiment. The processor unit changes the orientation of the softkey labels to match the presently detected orientation of the phone.  FIG. 10  illustrates the mobile phone in and upside down orientation with the softkey labels perfectly readable to the user. The processor may—as shown—also change the orientation of the information displayed in the main area of the display  3  (in this case the phone is in the idle mode and the operator logo is displayed). The position of the separate fields  21  is though not changed so that they remain proximate to the softkeys  9 .  
       FIG. 11  illustrates a fourth preferred embodiment the mobile communication terminal  1  according to the invention in the form of a mobile phone. The mobile phone, shown in the standard upright orientation, is similar to previously described mobile phone, however the first group  8  of keys as numeric keys, is arranged in a circular pattern.  
      With reference to  FIG. 12 , the keys  8  are made of a transparent material and can be provided with view limiting blinds  81 . Labels  24  are arranged on a rotary disk  23  there below. The disk  23  is formed by a film on which the labels  24  are printed. The labels are arranged in a circular pattern that matches the pattern of the keys  8 . The rotary disk is provided with at least two sets of labels, each set being visible in a different angular position of the disk  23 . The disk can be rotated clockwise in a stepped manner by operating a lever  25  in the direction of arrow  28 . A mechanism (not shown) translates the movement of the lever  25  into a rotary step of the disk  23 . A flexible intermediate layer  29  is arranged below the rotary disk  23 . Dome switches  31  mounted on a PCB  30  below the keys  8  are actuated through the film  23  and the flexible intermediate layer  29 .  
      The mobile phone comprises the same tilt sensor  20  as in the previous embodiments. The processor unit changes the orientation of the softkey labels to match the presently detected orientation of the phone.  FIG. 13  illustrates the mobile phone in and sideways orientation with the softkey labels and the labels  24  of the numeric keys perfectly readable to the user. The disk  23  shows now a set of labels wherein the numbers can be read in the sideways orientation of the phone. The processor may—as shown—also change the orientation of the information displayed in the main area of the display  3 . The position of the separate fields  21  is though not changed so that they remain proximate to the softkeys  9 .  
      The disk  23  may be provided with more than two label sets. The different label sets may relate to a different functionality of the keys, or to a different orientation of the label content. Accordingly, a switch may be connected to the rotary disk to inform the processor unit  18  of the present position of the rotary disk  23 , to adapt the functionality of the respective keys  8  to the visible label set. In a phone with user exchangeable covers—as well known in the art—the rotary disk  23  may also be user exchangeable to allow for further label sets to be employed with the phone. Hereto, the disks  23  are provided with a tag (not shown) that is recognized by the phone, so that the processor can be informed of the type of label sets that are present on the disk  23  that is in use. The tag could be magnetic, a transponder chip, or any other conventional identification means suitable for use inside a mobile communication terminal.  
      A sensor  34  ( FIG. 7 ) determines the present position of the rotary disk  23 . The sensor  34  interfaces with the processor unit  18  which in term determines the correct functionality for the key/dome switch associated with the presently shown key label.  
      Behind the rotary disk  23  another user exchangeable film with a background image may be provided (not shown). This user exchangeable film could be used to change the background color for the key labels or to provide a background image.  
      In another embodiment the rotary disk  23  is not provided with a handle  25  but is motor driven instead. A substrate motor  35  ( FIG. 7 ) controlled by the processor unit  18  moves the rotary disk  23  automatically to the desired position. The automatic repositioning of the rotary disc  23  may be triggered by a user command, a state change event of the phone, or in response to a change in orientation detected by the orientation sensor  20 .  
       FIG. 14  illustrates a fifth preferred embodiment the mobile communication terminal  1  according to the invention in the form of a mobile phone. The mobile phone, shown in the standard upright orientation, is similar to mobile phone described with reference to  FIGS. 9 and 10 , however, a multifunctional key  27  is provided above the display  3 . The key  27  could however be arranged in any other suitable place in the user interface. The multifunctional key  27  is provided with two hard labels printed thereon. The two hard labels relate to two different functions and can be read in two different orientations. In this example, one function is the activation of a camera not shown) to use the phone as a photo or video camera, the other function is the activation of games. For capturing images, the phone is held sideways with the key  27  on the left and the keys  8  on the right, thus rendering the phone more photo camera like. The phone is held sideways with the key  27  on the right and the keys  8  on the left in gaming applications, allowing for easier access of the keys on the right and left side of the display during gaming, thus rendering the phone more suitable for gaming.  
       FIG. 15  shows a variation of the phone of  FIG. 14 . The hard labels are in this variation printed next to the key  27 . In both variations of this embodiment the labels can be provided with back lighting that can be alternatively activated, thus indicating to the user which of the functions is presently active.  
       FIG. 16  illustrates a fifth preferred embodiment the mobile communication terminal  1  according to the invention in the form of a mobile phone. The mobile phone, shown in the standard upright orientation, is similar to mobile phone described with reference to  FIGS. 9 and 10 , however, the keys  8  are transparent and the labels there behind are arranged on a slidable substrate  23 ′ as shown in more detail in  FIG. 17 , the keys  8  are made of a transparent material and can be provided with view limiting blinds  81 . The slidable substrate  23 ′ is formed by a film on which the labels  24  are printed. The labels are arranged in a rectangular pattern that matches the pattern of the layout of the keys  8 . The slidable substrate  23 ′ is provided with three sets of labels  24 , each set being visible in a different position of the slidable substrate  23 ′. The slidable substrate  23 ′ can be slid in the direction of arrows  33  by means of a handle  32  in three positions as illustrated by  FIGS. 18 and 19 . A flexible intermediate layer  29  is arranged below the slidable substrate  23 ′. Dome switches  31  below the keys  8  are actuated through the slidable substrate  23 ′ and the intermediate layer  29 .  
      In  FIG. 16 , the slidable substrate  23 ′ is in the upper position and a set of labels with the alphanumerical functions for the keys  8  is visible.  
       FIG. 18  illustrates the mobile phone in the upright position and the slidable substrate  23 ′ in the middle position with a second set of labels visible. The second set of labels is numerical only and in a larger font for ease of reading, in particular for visually impaired users.  
      The mobile phone comprises the same tilt sensor  20  as in the previous embodiments. The processor unit  18  changes the orientation of the softkey labels to match the presently detected orientation of the phone.  
       FIG. 19  illustrates the mobile phone in the upside down orientation with the softkey labels  22  and the labels  24  keys perfectly readable to the user. The slidable substrate  23 ′ is moved to the lower position and shows now a set of labels wherein the numbers and letters can be read in the upside down orientation of the phone. The processor unit  18  may—as shown—also change the orientation of the information displayed in the main area of the display  3 . The position of the separate fields  21  is though not changed so that they remain proximate to the softkeys  9 .  
      The slidable substrate  23 ′ may be provided with more than only two—or more than three—label sets. The different label sets may relate to a different functionality of the keys, or to a different orientation of the label content.  
       FIG. 20  illustrates a third embodiment for rendering different labels visible under the keys  8 . In this embodiment the label sets are arranged directly on the flexible intermediate layer  29 . The keys  8  are fitted in a slidable keypad section  26 . The slidable keypad section  26  can be slid in the direction of arrow  36  to move the keys  8  above a different label. Below each label  24  a dome switch  31  is arranged on the PCB  30 .  
       FIG. 21  illustrates a fourth embodiment for rendering labels readable in different orientations. In this embodiment, the key is provided with a holographic label  37  that is preferably molded into the plastic key. The holographic label  37  can be read in at least two directions. The label content may be identical for each orientation, or different functions can be used in different orientations. The key  8  with the holographic label  37  is arranged in a conventional manner above a dome switch  31  on the PCB  30 . A plurality of adjacent keys  8  may be interconnected by attaching them to a flexible keymat  40  that facilitates ease of insertion upon assembly. This type of arrangement can be used in combination with any of the previously described embodiments.  
      The hologram may be created by any commercially available holographic technology, such as 
          diffractive optically variable image device (DOVID) using an array of tiny diffractive pixels,     embossed, by embossing the impression of the hologram into the substrate material,     photopolymer, using a photosensitive medium used for display holograms, usually on a polyester film substrate.        

      FIGS.  22  to  24  illustrate an arrangement to change label orientation using polarized films. The key  8  is attached to a flexible keymat  40  that interconnects a plurality of keys  8 . A film  48  with polarized areas is arranged below the keymat  40 . Different areas can have different polarization orientations. A preferably white film  45  is arranged below film  48 . Black and white or color key labels  24  are printed on the white film  45  below the keys  8 . The printed areas are covered by polarized film sections  46 . The polarized film sections  46  are divided in sub-sections with differently polarized areas and non-polarized areas. A light guide layer  47  provides for backlighting. A dome switch  31  on the PCB  30  is arranged under a protrusion  49  on the bottom side of the white film  45 . The film  48  is movable by sliding and/or rotation. When the film  48  is moved relative to the film sections  46  different areas of the printed label  24  become visible, depending on the arrangement of the polarized areas and on the layout of the printed label  24 .  
       FIGS. 23 and 24  show how an upright part of label  24  and upside down part of label  24  become alternatingly visible by rotating the film  48 . In this example the upper part of the film section  46  is polarized in a first direction with an upright print part of label  24  there under. The lower part of film section  46  is polarized in a second direction with an upside down part of printed label  24  there under. In a first position of the film  48  ( FIG. 23 ) the upright part of the alphanumerical label  24  of key  8  is visible. When the film  48  is turned 90° ( FIG. 24 ) the label  24  changes, and is in this example upside down part becomes visible, thus facilitating the use of a terminal in which the key is used in an upside down orientation. The rotation of the film  48  may be effected by a handle driven mechanism (not shown) or any other conventional means to rotate a disk. The same effect could also be obtained by a slightly different arrangement of the polarized areas and by sliding the film  48  up and down or any other direction. This type of arrangement can be used in combination with any of the previously described embodiments.  
       FIG. 25  illustrates a fifth arrangement to change visible label sections. The transparent key  8  is provided with a blind  81 . The opening in the blind, and the height relative to the labels  24  under the key  8  is such that there is a keyhole effect. Two labels  24  are arranged on a keymat  40 , each label  24  being offset form the center of the key  8 . A dome switch  31  on the PCB  30  and below the flexible substrate  29  is arranged right under the key  8 . One of the labels  24  is completely visible from viewpoint  50 . The other label  24  is completely visible from viewpoint  51 , as indicted by the interrupted lines. Since the users usually hold a mobile terminal with the top tilted away from themselves, only one of the labels will be completely visible to the user. The content of the upper label  24  is in the upright orientation and will be seen when the terminal is held in the upright position with the top of the terminal titled slightly away from the user. The content of the lower label  24  is in the upside down orientation and will be seen when the terminal is held in the upside down position with the “top” of the terminal titled slightly away from the user. The same arrangement could of course also be created when the terminal is in the two different sideways orientations. This type of arrangement can be used in combination with any of the previously described embodiments.  
       FIG. 26  illustrates a sixth arrangement to change visible label sections. A lenticular screen  53  with two interlaced label images printed directly on the back of the plastic lenticular screen is placed at the bottom of a cavity  54  in the key  8 . One of the label images is visible from viewpoint  55 , the other from viewpoint  56 . The two images relate preferably to the same content in opposite orientations, e.g. upright and upside down. A plurality of adjacent keys  8  may be interconnected by attaching them to a flexible keymat  40  that facilitates ease of insertion upon assembly. Below the key  8  a dome switch  31  is arranged on the PCB  30 . This type of arrangement can be used in combination with any of the previously described embodiments.  
      Although the present invention has been described in detail for purpose of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art without departing from the scope of the invention.  
      Thus, while the preferred embodiments of the devices and methods have been described in reference to the environment in which they were developed, they are merely illustrative of the principles of the inventions. Other embodiments and configurations may be devised without departing from the scope of the appended claims.