Abstract:
A palm-sized handheld device includes a body casing having a top end and a bottom end. In accordance with one embodiment of the invention, the device also includes a display screen proximately disposed near the bottom end of the device, and a plurality of input keys proximately disposed near said top end of the device above the input display screen.  
     As a result of such a configuration, accessibility to the input keys by users&#39; thumbs is improved while glare from a bright light source on the display screen may be decreased.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to the field of handheld digital devices. More specifically, the present invention relates to the placement of data entry keys with respect to the display within each of these devices.  
           [0003]    2. Background Information  
           [0004]    Advances in computer and telecommunication technology have led to the wide spread adoption and miniaturization of electronic organization and communication devices, such as personal digital assistants (PDAs) and wireless pagers. Although smaller versions of such devices allow increased portability, the reduction in size is typically accompanied by awkward keypad positioning thereby hindering one&#39;s ease of use and possibly causing discomfort to the user.  
           [0005]    [0005]FIG. 1 illustrates an exemplary prior art PDA. As illustrated, prior art PDA  100  typically includes body-casing  116  with top end  118 A, bottom end  118 B, left side  119 A and right side  119 B, as well as keypad  102 , disposed near bottom end  118 B. Keypad  102  represents a set of small, fingertip-sized data entry keys configured in a standard “QWERTY” arrangement to facilitate a user in providing numeric and/or alphanumeric input into PDA  100 . Keypad  102  further includes function keys  120 - 121 , which are linked to pre-programmed functions such as character mode and/or operating mode switching activated by the press of the appropriate function keys  120 - 121  by a user.  
           [0006]    PDA  100  further includes display screen  108 , which is disposed near top end  118 A above keypad  102 , and is used to echo numeric or alphanumeric inputs entered by a user, as well as to display various graphical and/or alphanumeric messages, menu options, control information, status information, and so forth. For example, display screen  108  is illustrated as displaying graphical icons  110 - 114 , and date and time information  104 .  
           [0007]    Although the physical size of body casing  116  may vary, PDA  100  is typically palm-sized so as to fit within the palm of an average user&#39;s hand. During normal use, by virtue of its configuration with keypad  102  disposed near bottom end  118 B and display screen  108  disposed near top end  118 A above keypad  102 , a user will typically rest body casing  116  on one or both of their index fingers formed into an arch with at least one of the user&#39;s thumbs being utilized to pinch PDA  100  against the arched forefinger(s), thus leaving only one of the user&#39;s thumb free to enter and/or manipulate data via keypad  102 . Accordingly, the user typically severely arches their thumbs into an inconvenient and uncomfortable position in order to operate PDA  100 , thereby exposing the user to possible discomfort. Furthermore, due to keypad  102  being disposed below display screen  108 , display screen  108  is rendered vulnerable to bright light sources such as the sun. In situations where display screen  108  represents a backlit display for example, such bright light shone on display screen  108  can severely interfere with the user&#39;s viewing of information displayed within display screen  108 .  
           [0008]    Therefore, a more user-friendly design, in particular, one that improves thumb manipulability of the keypad is desired.  
         SUMMARY OF THE INVENTION  
         [0009]    A palm-sized handheld device includes a body casing having a top end and a bottom end. In accordance with one embodiment of the invention, the device also includes a display screen proximately disposed near the bottom end of the device, and a plurality of input keys proximately disposed near said top end of the device above the input display screen.  
           [0010]    As a result of such a configuration, accessibility to the input keys by users&#39; thumbs is improved while glare from a bright light source on the display screen may be decreased.  
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0011]    The present invention will be described by way of exemplary embodiments, but not limitations, illustrated in the accompanying drawings in which like references denote similar elements, and in which:  
         [0012]    [0012]FIG. 1 illustrates a typical prior art PDA;  
         [0013]    [0013]FIG. 2 illustrates a PDA of the present invention incorporated with a keypad disposed above the display, in accordance with one embodiment;  
         [0014]    [0014]FIG. 3 further illustrates PDA  200  of FIG. 2, incorporated with the teachings of the present invention, in accordance with one embodiment;  
         [0015]    [0015]FIG. 4 illustrates a PDA incorporating various advantageous aspects of the present invention, in accordance with a second embodiment; and  
         [0016]    FIGS.  5 A- 5 E illustrate a PDA incorporating various advantageous aspects of the present invention, in accordance with a third embodiment.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]    In the following description, various aspects of the present invention will be described. However, it will be apparent to those skilled in the art that the present invention may be practiced with only some or all aspects of the present invention. For purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the present invention. However, it will also be apparent to one skilled in the art that the present invention may be practiced without the specific details. In other instances, well known features are omitted or simplified in order not to obscure the present invention. The phrase “in one embodiment” will be used repeatedly, however the phrase does not necessarily refer to the same embodiment, although it may.  
         [0018]    Referring now to FIG. 2, wherein a front view of a personal digital assistant (PDA)  200 , incorporated with the teachings of the present invention in accordance with one embodiment, is shown. PDA  200  includes body casing  216  having a top end  218 A, a bottom end  218 B, a left side  219 A, a right side  219 B, display screen  208 , left key set  202 A and right key set  202 B. Except for the teachings of the present invention, each of these elements is used to provide the same functionality as the functionality provided by the corresponding element of prior art PDA  100  described earlier, that is for the input of numeric and/or alphanumeric data, for displaying various graphical and/or alphanumeric messages, and so forth. However, unlike prior art PDA  100  of FIG. 1, the keypad of PDA  200  has been advantageously and ergonomically disposed near top edge  218 A above display screen  208  as well as divided into left key set  202 A and right key set  202 B. Such an arrangement provides convenient access to the data input keys without causing thumb strain caused by prior art PDA configurations, and without causing users&#39; thumbs to interfere with viewing of the text and/or images displayed on display screen  208 . In one embodiment of the invention, display screen  208  is rectangular in shape having a top edge  208 A, a bottom edge  208 B disposed below top edge  208 A, a left side and a right side. In one embodiment, at least one of left key set  202 A and right key set  202 B is disposed at an angle with respect to at least one of bottom edge  208 B and/or top edge  202 A of display screen  208 . In one embodiment, at least one of left key set  202 A and right key set  202 B is disposed at approximately a forty-five degree angle with respect to at least one of bottom edge  208 B and/or top edge  202 A of display screen  208 .  
         [0019]    Note that top end  218 A and bottom end  21  BB (as well as top edge  202 A and bottom edge  208 B) are objectively determined. A device such as PDA  200  having display screen  208  necessarily has a display orientation. For example, textual data are either rendered from left to right and top to bottom, as denoted by arrows  220 A and  220 B respectively, as in the case of the English language, or right to left and top to bottom, as denoted by arrows  222 A and  222 B respectively, as in the case of the Hebrew language, or top to bottom and right to left, as denoted by arrows  224 A and  224 B respectively, as in the case of the Chinese language. Thus the manner in which textual data are rendered defines which end is the top end, and which end is the bottom end of PDA  200 . Accordingly, an element X of PDA  200  is necessarily above element Y of PDA  200  and element Y is necessarily below element X, if element X is closer to the objectively determinable top end of PDA  200  or if element Y is closer to the objectively determinable bottom end of PDA  200 .  
         [0020]    As illustrated, display screen  208  represents a broad category of display screens, such as a liquid crystal display (LCD), to display text and/or graphical information such as status information and input and output data the user may be interested in viewing. For example, display screen  208  includes date and time display  204  designed to inform a user of the current date and time, as well as graphical icons  210 - 214  designed to provide a user with expedited access to a variety of operating functions that PDA  200  may be equipped to perform.  
         [0021]    Depending upon the particular implementation, PDA  200  may be equipped to provide services including but not limited to electronic mail services, text editing services, file storage services, and calendaring services. For example, mail icon  210  may represent an electronic mail function, which when selected, provides a user with the ability to transmit and/or receive electronic messages. Similarly, edit icon  211  may represent a text editing function, which when selected, provides a user with the ability to create and/or edit simple text messages. Likewise, calendar icon  214  may represent various calendaring functions available to a user. These and other functions described in the context of PDA  200  are intended to be merely illustrative and should not be read as limiting the present invention. Accordingly, PDA  200  may represent a wide variety of devices that provide a similarly wide variety of functionalities. For example, PDA  200  may be implemented as a multi-function personal digital assistant, or as a dedicated personal paging device, provided that one or more data input keys and/or devices are disposed above display screen  208 . In one embodiment, PDA  200  is approximately 3.5 inches in length measured from left side  219 A to right side  219 B, and 2.5 inches in width measured from top end  218 A to bottom end  218 B.  
         [0022]    Body casing  216  further includes finger mouse  205  as well as left mouse button  203 A and right mouse button  203 B. In one embodiment finger mouse  205  is ergonomically disposed near top end  218 A so as to correspond to the natural arch of a user&#39;s index finger when naturally grasping a device such as PDA  200 . In FIG. 2, finger mouse  205  is illustrated as being disposed above right key set  202 B, however finger mouse  205  or an additional finger mouse may be disposed above left key set  202 A. Furthermore, other user input devices such as a track wheel and/or roller ball may be utilized in addition to, or in place of finger mouse  205 . However, such a user input device is not required. In the illustrated embodiment, left mouse button  203 A is disposed above display screen  208  and at least partially below left key set  202 A so as to provide convenient access by one&#39;s left thumb, whereas right mouse button  203 B is disposed above display screen  208  and at least partially below right key set  202 B so as to provide convenient access by one&#39;s right thumb. In one embodiment, left mouse button  203 A is disposed above display screen  208  and at least partially between left side  219 A and left key set  202 A, whereas right mouse button  203 B is disposed above display screen  208  and at least partially between right side  219 B and right key set  202 B.  
         [0023]    Referring now to FIG. 3, wherein PDA  200  is further illustrated as incorporating the teachings of the present invention, in accordance with one embodiment. As described above with respect to FIG. 2, PDA  200  of FIG. 3 includes display screen  208  disposed near bottom end  218 B, below left mouse button  203 A and left key set  202 A, as well as right mouse button  203 B and right key set  202 B, which are both partially hidden by right hand  306 . Right hand  306  represents a user&#39;s right hand grasping PDA  200  in a natural grasping position such that index finger  309  may be utilized to manipulate finger mouse  205 , and thumb  315  may be utilized to manipulate right key set  202 B, while at the same time limiting the strain normally placed on right thumb  315  and/or right hand  306  by keypad configurations of the prior art. At the same time, the novel and advantageous configuration of PDA  200  likewise facilitates natural and reduced-strain grasping of PDA  200  by a user&#39;s left hand (not shown). Accordingly, finger mouse  205  may be disposed near top edge  218 A in a location more conducive for use with a finger from a user&#39;s left hand. However, it should be noted that the advantageous configuration of the present invention facilitates single-hand usage of PDA  200 , thereby freeing a user&#39;s second hand for other tasks.  
         [0024]    In addition to facilitating ergonomic use of PDA  200 , the novel arrangement of display screen  208  below left key set  202 A and right key set  202 B further provides a user with the ability to shield display screen  208  from glare caused by light source  330  without hindering use of PDA  200 . For example, when PDA  200  is grasped in a natural and comfortable manner such as is illustrated in FIG. 3, right hand  306  (as well as a user&#39;s left hand) necessarily tends to shield PDA  200  from light source  330  as illustrated by shadow  307 . Body casing configurations of the prior art, however, include display screens that are disposed above the keypad, leaving the display screen vulnerable to distracting glare. It should be noted that the novel configuration of body casing  216  is such that even as thumb  307  and index finger  309  are used to enter data via right key set  202 B and finger mouse  205  respectively, right hand  306  (as well as a left hand) is nonetheless continually positioned so as to block unwanted and distracting light from light source  330 .  
         [0025]    [0025]FIG. 4 illustrates a PDA incorporating advantageous aspects of the present invention, in accordance with a second embodiment. PDA  400  is shown being grasped by right hand  306 . PDA  400  is similarly configured to PDA  200 , however, PDA  400  includes left finger mouse  405 A in addition to right finger mouse  405 B. Both left finger mouse  405 A and right finger mouse  405 B may be activated concurrently, or either may be selectively activated based upon user preference. Additionally, PDA  400  includes body casing  416  having left key set  402 A disposed near left side  419 A and right key set  402 B disposed near right side  419 B. Each of left key set  402 A and right key set  402 B are arranged in two or more concentric circles and/or arches. Depending upon implementation, left key set  402 A may include all alphabetical characters, whereas right key set  402 B may include all numeric and/or special characters. Similarly, both left key set  402 A and right key set  402 B may include alphanumeric characters that are organized in a variety of positional relationships. Furthermore, left mouse button  403 A is formed in the shape of an oval rather than a triangle as illustrated in FIG. 2 and FIG. 3. It should be noted that data input keys and mouse buttons of a variety of shapes and sizes may similarly be utilized.  
         [0026]    FIGS.  5 A-E illustrate a PDA incorporating advantageous aspects of the present invention, in accordance with a third embodiment. PDA  500  includes upper body portion  550  having an outer end  552  and an inner end  554 . Upper body portion  550  further includes left key set  502 A and right key set  502 B. PDA  500  also includes lower body portion  551  having inner end  555  and outer end  553 , as well as display  508 . In one embodiment, upper body portion  550  and lower body portion  551  are pivotally coupled together by hinges  542  and  544 . It should be noted that a single hinge or multiple hinges might also be used. Similarly, connection mechanisms other than hinges may be used to allow movement of outer end  552  towards and away from outer end  553  while inner ends  554  and  555  remain in a substantially fixed location relative to each other. Such a hinged configuration not only provides advantageous positioning of display screen  508  below the left and right key sets, but also enables a user to close PDA  500  thereby shielding display screen  508  from exposure to damage and dust for example.  
         [0027]    Thus, a palm-sized hendheld device having an ergonomic inverted keyboard has been disclosed. In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.