Patent Publication Number: US-2006012573-A1

Title: Apparatus and method for dual use of a numeric keypad

Description:
FIELD OF THE INVENTION  
      The present invention relates generally to electronic devices and more specifically to techniques for using a numeric keypad in such a device.  
     BACKGROUND OF THE INVENTION  
      A variety of computing devices such desktop computers, laptop computers, notebook computers, and personal digital assistants (PDAs) include an electronic keyboard and a display. Some devices also include a numeric keypad for entering numbers and performing simple calculations. The numeric keypad offers a convenient alternative to the top row of keys for inputting numbers and special symbols found on most typewriter-style keyboards. However, since the numeric keypad is operative only when the computing device to which it is connected or of which it is a part is powered up, the numeric keypad gets used only for the single purpose cited above.  
      It is thus apparent that there is a need in the art for an apparatus and method for dual use of a numeric keypad.  
     SUMMARY OF THE INVENTION  
      A method for sharing a numeric keypad between a first electronic device and a second electronic device is provided. The second electronic device may be activated and the numeric keypad may be interfaced with the second electronic device, when a first input condition is present. The numeric keypad may instead be interfaced with the first electronic device, when a second input condition is present. The second electronic device may be integrated with a keyboard connected with the first electronic device, or it may be integrated with the first electronic device itself. The second electronic device may provide one or more functions such as a calculator, clock/calendar, alarm clock, or timer even when the first electronic device is turned off. Apparatuses incorporating the method are also provided.  
      Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a functional block diagram of an electronic system that includes a dual-use numeric keypad in accordance with an illustrative embodiment of the invention.  
       FIG. 2  is an illustration of a notebook computer that includes a dual-use numeric keypad in accordance with an illustrative embodiment of the invention.  
       FIG. 3  is a flowchart of a method for sharing a numeric keypad between a first electronic device and a second electronic device in accordance with an illustrative embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       FIG. 1  is a functional block diagram of an electronic system  100  that includes a dual-use numeric keypad in accordance with an illustrative embodiment of the invention. In  FIG. 1 , primary electronic device  105  and secondary electronic device  110  are both electrically connected with numeric keypad  115  via switch  120 . As those skilled in the art will recognize, switch  120  may conduct both data and power signals to primary electronic device  105  and secondary electronic device  110  via connections  125 ,  130 , and  135 . Principles for designing and implementing switch  120  are well known in the art. Secondary electronic device  110  may include a display  140 . Primary electronic device  105  may have a system battery  145  that is controlled by on/off switch  150 . In some embodiments, system battery  145  may power both primary electronic device  105  and secondary electronic device  110 , in which case system battery  145  may be routed through switch  120  to secondary electronic device  110 . In other embodiments, secondary electronic device  110  may be powered by an independent power source  155 . For example, independent power source  155  may be a dedicated battery. In some embodiments, a solar cell may be used to power secondary electronic device  110  independently of primary electronic device  105 .  
      Primary secondary device  105  may be any electronic device that uses a keyboard, such as a desktop PC or a portable computing device. Portable computing devices include, but are not limited to, laptop computers, notebook computers, personal digital assistants (PDAs), radiotelephones, (e.g., cellular phones), and digital imaging devices (e.g., digital cameras and digital camcorders). In general, secondary electronic device  110  may be any electronic device that performs at least one function. Examples include, but are not limited to, a calculator, a clock, a calendar, an alarm clock, a timer, or any combination thereof. Switch  120  may be configured to activate secondary device  110  and interface numeric keypad  115  with secondary electronic device  110 , when switch  120  is in a first position. In some embodiments, this first position may be labeled “on.” Switch  120  may be further configured to interface numeric keypad  115  with primary electronic device  105 , when switch  120  is in a second position. In some embodiments, this second position may be labeled “off.” The activation of secondary device  110 , including associated display  140 , may be performed independently of the power state of primary electronic device  105 , making the functionality of secondary electronic device  110  available to a user at any time.  
      The principles illustrated in  FIG. 1  may be applied, for example, to a notebook computer. Larger displays on recent notebook computers have resulted in larger areas of unused space on the keyboard deck. A portion of that unused space may be used to provide a secondary electronic device  110  that can share numeric keypad  115 . Although a more detailed description is provided in the context of notebook computers, the principles of the invention are applicable to any primary electronic device  105  with the characteristics mentioned above, including other types of portable computing devices.  
       FIG. 2  is an illustration of a notebook computer  200  that includes a dual-use numeric keypad  115  in accordance with an illustrative embodiment of the invention. One or more component parts of notebook computer  200  are encased in enclosure  205 . One of the hinged halves of notebook computer  200  may include a keyboard deck  210 , which in turn may comprise a typewriter-style keyboard  215  (a set of alphanumeric keys arranged in a typewriter-style layout) and numeric keypad  115 . In such an embodiment, notebook computer  200  is the primary electronic device  105 . Secondary electronic device  110  may be concealed within enclosure  205 . For example, secondary electronic device  110  may be implemented on a small printed-circuit board. Display  140  may be visible from the outside of enclosure  205  to display functions such as calculations, clock/calendar, alarm clock, timer, or a combination thereof. In  FIG. 2 , switch  120  selects between the interfacing of numeric keypad with notebook computer  200  or secondary electronic device  110 . Switch  120  may additionally power on secondary electronic device  110  independently of the power state of notebook computer  200 . Both notebook computer  200  and secondary electronic device  110  may be powered by system battery  145 , or secondary electronic device  110  may have its own separate power source  155  (e.g., a solar cell or other dedicated battery). Notebook computer  200  typically also includes a display  220 .  
      A user may use secondary electronic device  110  by simply setting switch  120  to the appropriate position to activate secondary electronic device  110  and interface numeric keypad  115  with secondary electronic device  110 . In some embodiments, this position of switch  120  may be labeled “on” to signify that secondary electronic device  110  is turned on when switch  120  is in that position. When switch  120  is set to a different position, numeric keypad  115  may be interfaced with notebook computer  200 . That is, numeric keypad  115  may act as a portion of keyboard deck  210  of notebook computer  200  in the usual fashion. In some embodiments, this different position of switch  120  may be labeled “off” to signify that secondary electronic device  110  is not active when switch  120  is in that position.  
      In some embodiments, the functionality of keyboard deck  210  in  FIG. 2  may be embodied in an electronic keyboard that is separate from primary electronic device  105 . For example, a desktop computer usually has an electronic keyboard that is separate from the central processing unit (CPU). Such an electronic keyboard may be electrically connected with the CPU via either a wired or wireless connection. In that context, the same principles of the invention discussed above apply, except that secondary electronic device  110  may be integrated with a separate electronic keyboard that is electrically connected with primary electronic device  105 . Such an electronic keyboard may be very similar in function and layout to keyboard deck  210  of notebook computer  200 . For example, the electronic keyboard may include a set of alphanumeric keys with a typewriter-style layout that is interfaced with primary electronic device  105  (similar to typewriter-style keyboard  215  in  FIG. 2 ). Additionally, the separate electronic keyboard may include a numeric keypad  115  that, under control of switch  120 , may interface with either primary electronic device  105  or secondary electronic device  110 , as explained above.  
      Though it is possible to combine a secondary electronic device with an external numeric keypad that can be connected with a portable computing device or a desktop PC via, for example, a USB cable, the approach described above in which the secondary electronic device  110  is integrated with the portable computing device or a typewriter-style electronic keyboard offers distinct advantages. First, it saves space since the numeric keypad is part of the portable computing device or typewriter-style electronic keyboard. Secondly, it is more convenient since there is no need for the user to carry or connect a separate device to enjoy the functionality of numeric keypad  115  and secondary electronic device  110 .  
       FIG. 3  is a flowchart of a method for sharing a numeric keypad  115  between a first electronic device  105  and a second electronic device  110  in accordance with an illustrative embodiment of the invention. At  305 , a first input condition is tested. If the first input condition is present, secondary electronic device  110  may be activated and numeric keypad  115  may be interfaced with secondary electronic device  110  at  310 . If the first input condition is not present, the method proceeds to  315 , where a second input condition is tested. If the second input condition is present at  315 , numeric keypad  115  is interfaced with primary electronic device  105  at  320 . If secondary electronic device  110  had been activated prior to step  320 , secondary electronic device  110  may also be deactivated (e.g., powered off) at  320 . In some embodiments, first and second input conditions may comprise different positions of switch  120 . For example, switch  120  may be a toggle switch labeled “on” and “off,” as described above. Where switch  120  does comprise a toggle switch, the absence of the first condition at  305 , of course, necessarily implies the presence of the second input condition at  315 , and vice versa. In general, however, switch  120  may have more than two states, as those skilled in the art will recognize.  
      The foregoing description of the present invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and other modifications and variations may be possible in light of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and various modifications as are suited to the particular use contemplated. It is intended that the appended claims be construed to include other alternative embodiments of the invention except insofar as limited by the prior art.