Abstract:
The present invention is related to a system and method for providing input mechanisms in a handheld electronic device. The handheld electronic device includes a casing having a first surface and a second surface, where the second surface faces away from a user of the device when the first surface faces toward the user. An input control is arranged on the second surface. An input mechanism is configured to detect a user input event via the input control. A display is arranged on the first surface and configured to present a visual indication identifying the input control responsive to the user input event.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 10/834,406, titled “METHOD AND SYSTEM FOR PROVIDING INPUT MECHANISMS ON A HANDHELD ELECTRONIC DEVICE”, filed on Apr. 29, 2004, the entire disclosure of which is here incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to handheld electronic devices, and more particularly to input mechanisms on a handheld electronic device. 
       BACKGROUND OF THE INVENTION 
       [0003]    Technological improvements in processing speed and power and in memory capacity have opened the door to handheld electronic devices that provide a variety of functions that were heretofore found only in larger and bulkier devices. For instance, manufacturers have been able to shrink the size of a mobile phone to fit in the palm of a user&#39;s hand. 
         [0004]    While smaller devices are generally perceived to be desirable, a problem arises when the space for physical features of the device diminishes. For example, in most cases, a mobile phone has a minimum number of alphanumeric keys, and additional input keys, e.g., navigation and select keys. These keys are typically located on one face of the device, which also typically includes a display, e.g., an LCD, so that the user can see what he or she has entered, or so that the user can access other functions of the device. 
         [0005]    To make room for the input keys and display on the device face, the size of the keys and/or display, and the spacing between keys is usually decreased. Nevertheless, because the keys are so small and the number so many, it becomes difficult to distinguish between the keys. Moreover, even if the user can make such a distinction, it is difficult to press the desired key because the space between keys is so small. For individuals with large fingers, this can be particularly frustrating. 
         [0006]    To address this problem, some devices place direction related keys, i.e., navigation keys, on a side surface perpendicular to the device face. Nevertheless, because these handheld electronic devices are slim devices, the side surface is thin and the keys must be positioned in a row along the side surface. Accordingly, navigation keys assigned to allow the user to navigate in a direction perpendicular to the row, i.e., right or left if the keys are on the left or right side of the device, are not intuitive for the user. Other devices offer a touchpad on a backside of the device, i.e., on the surface opposing the device face. (See, e.g., U.S. Pat. No. 5,543,588, entitled “Touch Pad Driven Handheld Computing Device” issued Aug. 6, 1996 to Bisset et al.). Here, the user navigates by tracing his or her finger on the surface of the touchpad to control the movement of a cursor on the display. Nevertheless, compared to input keys, a touchpad is more expensive, consumes more power, and requires more complex programming. 
         [0007]    Each of the above described devices presents an additional disadvantage as well. For each device, the location of the navigation mechanism is fixed. Thus, if the user is not comfortable having the navigation mechanism facing away from him or her as the user is viewing the display, the user cannot change the position of the navigation mechanism. 
         [0008]    Accordingly, a need exists for a system and method that provides navigation mechanisms, such as input keys, on a handheld electronic device. The system and method should be highly intuitive for the user, while being cost effective and efficient. The present invention addresses such a need. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention is related to a system and method for providing input mechanisms in a handheld electronic device. In a first aspect, the handheld electronic device according to the present invention includes a casing having a first surface and an opposing second surface, where the first surface includes a display on which a user interface is displayed to a user of the device, a plurality of input keys on the second surface, a layout of the plurality of input keys displayed on the display, and means for allowing the user to enter commands into the device by pressing at least one of the plurality of input keys, whereby the layout allows the user to select an appropriate input key of the plurality of input keys associated with a particular command without viewing the input key. 
         [0010]    In a second aspect, the handheld electronic device includes a casing having a first surface and an opposing second surface, where the first surface includes a display on which a user interface is displayed to a user of the device, a hinge mechanism between the first and second surfaces such that the second surface rotates back and forth between a first position and a second position, where the first position is when the second surface is opposing the first surface and facing away from the user, and the second position is when the second surface is substantially co-planar with the first surface and facing the use, at least one input mechanism on the second surface, and means for allowing the user to enter commands into the device by activating the at least one input mechanism. 
         [0011]    By locating input mechanisms such as input keys on another surface, i.e., the back face of the device, more or better features can be included on the surface facing the user, i.e., the front face. For instance, because fewer buttons are located on the front face, there is more space available for a larger display. Also, the button arrangement is less cluttered and the spacing between buttons can be increased so that the likelihood of pressing an incorrect button is decreased. When the input mechanisms are facing away from the user, a layout of the input mechanisms is displayed to the user so that the user can activate a desired mechanism. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0012]      FIGS. 1A and 1B  are front and back views, respectively, of a handheld electronic device according to a preferred embodiment of the present invention. 
           [0013]      FIGS. 2A ,  2 B and  2 C back and front views of a handheld electronic device according to another preferred embodiment of the present invention. 
           [0014]      FIGS. 3A and 3B  are back and front views, respectively, of a handheld electronic device according to a third preferred embodiment of the present invention. 
           [0015]      FIG. 4  is a flowchart illustrating a method for displaying the layout of the input keys via touch sensitive keys according to a preferred embodiment of the present invention. 
           [0016]      FIG. 5  is a flowchart illustrating a process for reassigning direction related keys according to a preferred embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]    The present invention relates to handheld electronic devices, and more particularly to, input mechanisms on a handheld electronic device. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiments and the generic principles and features described herein will be readily apparent to those skilled in the art. For example, while the preferred embodiments are described with respect to a mobile phone, the principles described can also be applied to any handheld electronic device, such as a PDA, digital camera, MP3 Player, and the like. Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein. 
         [0018]    The present invention is described with respect to two embodiments. According to a first aspect of the present invention, the total number of input keys cluttered onto a front face of a handheld electronic device, such as a mobile phone, is reduced by locating a plurality of input keys on another surface, such as the back face of the device. A layout of the plurality of input keys is displayed to the user on the front face of the device so that the user can determine the appropriate key to press. By relocating the plurality of input keys onto the back face, the front face can include a larger display, larger input keys and adequate spacing between the remaining input keys, without sacrificing the functionality provided by the plurality of input keys on the other surface. Also, because the plurality of keys are on the back face of the device, the intuitive nature of directional keys can be maintained. 
         [0019]    In a second aspect of the present invention, at least one input mechanism, e.g., a plurality of direction related keys and/or a select key, are located on a panel that is hinged to the device in such a manner that the user can “flip out” the panel. For example, in a closed position, the panel (and keys) faces away from the user, and in a completely open position, it faces the user. Unlike conventional “flip” phones, however, the user has access to the plurality of keys in either position so that the user can choose in what position he or she would like to activate the at least one input mechanism. Moreover, in this aspect of the present invention, the device includes a sensor that senses the position of the panel, i.e., whether it is in the open or closed position. The sensor is coupled to an assigner that controls the directional assignment of direction related keys. The assigner ensures that the intuitive nature of the direction related keys is maintained with respect to the user. 
         [0020]      FIGS. 1A and 1B  are front and back views, respectively, of a handheld mobile phone according to the first aspect of a preferred embodiment of the present invention. The phone  100  includes a front face  120  and an opposing back face  122 . The front face  120  of the mobile phone  100  ( FIG. 1A ) includes a display  140  and ten (10) alphanumeric keys  160  typical of a phone. The display  140  is used to display a user interface (not shown) that typically includes a menu of functions from which the user can choose. 
         [0021]    According to the preferred embodiment of the present invention, input mechanisms including direction related keys  123 - 128  and non-direction related keys, e.g., a select button  129 , are located on the back face  122  ( FIG. 1B ) of the mobile phone  100 . Note that if the input mechanisms were to be located on the front face  120 , the size of the display  140  and keys and/or spacing between the keys would necessarily decrease. Thus, by locating the input mechanisms  123 - 129  on the back face  122 , the usability of the phone  100  is significantly improved. 
         [0022]    According to the preferred embodiment of the present invention, the directional aspects of the direction related keys  123 - 128  are correlated to the user&#39;s perspective. Thus, the directional aspects are opposite to those viewed from the back face  122 . For example, the input key on the left side of the back face  126  corresponds to the user&#39;s right when the user is viewing the front face  120 , and is assigned to be a right-menu button  126 . Similarly, the input key on the right side of the back face  128  corresponds to the user&#39;s left when the user is viewing the front face  120 , and is accordingly assigned to be a left-menu button  128 . When the user presses the direction related key  124  on the left side of the back face  122 , this causes a cursor on the display  140  to move to the right from the user&#39;s perspective. In this manner, the intuitive nature of the direction related keys  123 - 128  is maintained from the user&#39;s perspective. 
         [0023]    In a preferred embodiment, each of the input keys  123 - 129  includes an embossed pattern  130   a ,  130   b  on a surface touched by the user to assist the user in identifying the key, e.g.,  126 . To assist further the user, a layout  142  of the input keys  123 - 129  is displayed on the display  140  ( FIG. 1A ). With these additional features, the user can operate the input keys  123 - 129  without having to peek at the back face  122 . 
         [0024]    In an aspect of the preferred embodiment, the layout  142  is displayed upon request by the user by activating a display layout key  161  located on either the front face  120  or the back face  122  of the device. Alternatively, the input keys  123 - 129  are responsive to more than one touch pressure, i.e., they are touch-sensitive. A “light” touch at a first pressure indicates a request to display the layout  142 , while a “heavy” touch at a second pressure enters a command associated with the input key, e.g.,  126 . Preferably, to avoid an inadvertent request to display the layout  142 , a touch counter (not shown) is used to count the number of times the user applies the light touch to one or more input keys  123 - 129 . Only when the number of light touches exceeds a certain threshold value, e.g., three (3) touches, does the layout  142  display. 
         [0025]      FIG. 4  is a flowchart illustrating a method for displaying the layout  142  of the input keys  123 - 129  via the touch sensitive keys according to a preferred embodiment of the present invention. Referring to  FIGS. 1A ,  1 B and  4 , the process begins when an input event is detected (step  400 ), i.e., when an input key, e.g.,  126 , is touched. The device  100  determines whether the input event is a light touch (step  402 ). If it is, then it is determined whether the layout  142  is already displayed on the display  140  (step  404 ). If the layout  142  is displayed, then the input key touched  126  is highlighted on the layout  142  (step  412 ) to indicate to the user which key was touched. 
         [0026]    If the layout  142  is not already displayed (step  404 ), the touch counter (not shown) is incremented (step  406 ), and if the touch counter exceeds a certain threshold value (step  408 ), then the layout  142  is displayed and the touched key  126  is highlighted on the layout  142  (step  410 ). If the touch counter does not exceed the threshold (step  408 ), the process waits for another input event (step  400 ). 
         [0027]    If the input event is not a light touch (step  402 ), the touch counter is reset (step  414 ) and the layout  142  is removed from the display  140  (step  416 ). Then, the device  100  handles the input event (step  418 ), i.e., performs the command associated with the touched key  126 . 
         [0028]      FIG. 4  illustrates one preferred process for controlling the display of the layout  142 . Those skilled in the art would readily realize that other methods can be employed. For example, if the layout of the keys occupies a substantial portion of the display  140 , the layout  142  can be automatically removed, or the layout  142  can be automatically removed after a period of no activity. Such methods would be within the scope of the present invention. 
         [0029]    According to a second preferred embodiment of the present invention, the device is provided with a panel containing at least one input mechanism. The panel rotates to and from a first (closed) position from and to a second (open) position.  FIGS. 2A and 2B  are diagrams depicting a back face  220 ′ of a handheld mobile phone  200  according to the second preferred embodiment of the present invention. As is shown, the panel  222  is coupled to the device  200  by a hinge mechanism  230  such that the panel  222  rotates around the hinge mechanism  230  from the closed position (shown in  FIG. 2A ) to the open position ( FIG. 2B ) in the direction illustrated by the circular arrow, as shown in  FIGS. 2A and 2B . Note that the hinge mechanism  230  can also be located on the opposite side so that the panel  222  rotates in the opposite direction indicated by the arrow. 
         [0030]    In a preferred embodiment, input mechanisms, such as a touchpad  224  and direction-related keys, e.g., right and left menu buttons  226 ,  228 , are provided on the panel  222 . Notably, the input mechanisms  224 ,  226 ,  228  are operational in both the closed and open positions. Preferably, the directional assignments for direction-related keys  226 ,  228  are dependent on the position of the panel  222 . The position of the panel  222  is determined preferably by a sensor  232  located on the back face  220 ′ of the device  200  ( FIG. 2B ). For example, the sensor  232  can be a contact point that completes a circuit (not shown) when it comes in contact with a back surface  222 ′ of the panel  222 , or vice versa. Other methods of implementing the sensor  232  would be readily appreciated by those skilled in the art. 
         [0031]    The sensor  232  is coupled to an assigner  234 , which controls the directional assignment of the direction-related keys  226 ,  228  depending on the position of the panel  222 , i.e., whether the panel  222  is facing away from the user or toward the user. Note that when the panel  222  is in the closed (first) position ( FIG. 2A ), the panel  222  is facing away from the user. Accordingly, the key  226  on the left side of the panel  222  is assigned to the right-menu button. Whereas when the panel  222  is in the open (second) position ( FIG. 2C ), it is facing toward the user and the same key  226  on the left side of the panel  222  is reassigned to the left-menu button. 
         [0032]    The assigner  234  applies the same adjustment to the directional signals interpreted by the touchpad  224 . For instance, when the panel  222  is facing away from the user (closed position), a finger trace from the left side of the touchpad  224  to the right side of the touchpad  224  correlates to the movement of a cursor on the display  240  from the right side of the display  240  to the left side of the display  240 . Whereas, when the panel  222  is facing toward the user, the direction of the finger trace corresponds directly with the movement of the cursor on the display  240 . 
         [0033]      FIGS. 3A and 3B  are back and front views, respectively, of a handheld mobile phone according to a third preferred embodiment of the present invention. This embodiment is similar to that illustrated in  FIGS. 2A-2C  except that the hinging mechanism  330  is located on a bottom side of the phone  300  such that the panel  322  “flips” down, as illustrated in  FIG. 3B . Note that the directional assignments for input keys associated with a horizontal direction  326 ,  328 ,  336 ,  338 , i.e. left or right, are not affected by the position of the panel  322 . Whereas, the assignments for the input keys associated with a vertical direction  332 ,  334  are dependent on the panel  322  position. While  FIGS. 3A and 3B  show the hinging mechanism  330  located on the bottom side of the phone  300 , it is also possible to locate the hinging mechanism  330  on a top side of the phone  300  such that the panel  322  “flips” up. 
         [0034]      FIG. 5  is a flowchart illustrating a method for reassigning direction sensitive keys according to a preferred embodiment of the present invention. Referring to  FIGS. 2A ,  2 B,  2 C and  5 , the process begins when an input event is detected (step  500 ), i.e., when the user presses an input key  226 ,  228 . The device  200  determines whether the pressed key, i.e.,  226 , is a direction related button (step  502 ). If the pressed key is not a direction related button, i.e., the pressed key is an alphanumeric key or a select button  350  ( FIG. 3A ), the device  200  handles the input event (step  510 ), i.e., performs the command associated with the pressed key. 
         [0035]    If the pressed key is a direction related button  226  (step  502 ), the sensor  232  determines the position of the panel  222  (step  504 ) and relays that information to the assigner  234 . The assigner  234  then checks the directional assignment of the pressed input key  226  (step  506 ) and, if necessary, reassigns the key  226  to an opposite direction to maintain the directional aspect from the user&#39;s perspective (step  508 ). After the reassignment, the device  200  handles the input event (step  510 ), and awaits another input event (step  500 ). 
         [0036]    Note that the layout  142  feature of the first embodiment can also be implemented in conjunction with the second embodiment. When the panel  222  is in the closed position and facing away from the user, the layout  142  of the input mechanisms  224 ,  226 ,  228  can be displayed automatically or upon request by the user. 
         [0037]    Through aspects of the present invention, a plurality of input keys and mechanisms are relocated from the front face of the handheld electronic device to the back face and a layout of the input keys and mechanisms is displayed to a user on the front face. By locating the input keys and mechanisms on the back face, more or better features can be included on the front face facing the user. For instance, because fewer buttons are located on the front face, there is more space available for a larger display. Also, the button arrangement on the front face is less cluttered and the spacing between buttons can be increased so that the likelihood of pressing an incorrect button is decreased. Moreover, when input mechanisms are located on a swinging panel coupled to the device, the user can choose to operate the input mechanisms in more than one position. According to the preferred embodiment of the present invention, the directional aspects of direction related mechanisms are correlated to the user&#39;s perspective when the user is viewing the front face. Accordingly, regardless of the panel&#39;s position, the direction related keys remain intuitive to the user. 
         [0038]    Although the present invention has been described in accordance with the embodiment shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims.