Abstract:
A mobile communication device includes a keypad having an integrated display for displaying alphanumeric information. The mobile communication device includes a housing. A keypad including a plurality of keys is disposed on a front surface of said housing. A plurality of light elements are arranged to emit light through spaces bordering the keys of the keypad. The light elements collectively form a segmented display for displaying alphanumeric characters. A controller operatively connected to the light elements controls the light elements to display alphanumeric information.

Description:
RELATED APPLICATION 
       [0001]    This application claims the benefit of Chinese application number 200910159510.2, filed on May 27, 2009, which is incorporated herein by reference. 
       BACKGROUND 
       [0002]    The present invention relates generally to keypads for electronic devices and, more particularly, to a keypad for electronic devices with an integrated alphanumeric display. 
         [0003]    Most cellular telephones, as well as other types of electronic devices, include a keypad and a display to facilitate user interaction with the device. When the cellular telephone is not in use, the display can be used to display the current date and time. Many people now use cell phones, rather than watches, to check the time of day. 
         [0004]    Using a cell phone display to display the time of day has some disadvantages. First, most cell phones have limited battery power and using the display to display the current date and time consumes power. Also, the displays on many cell phones, such as flip phones and slide phones, are frequently covered when the cell phone is not in use. Therefore, the user must open the cell phone in order to check the time. 
         [0005]    Because many people rely on cell phones as the primary means for checking time, there is a need to improve the display of the date and time on a cellular telephone and other portable electronic devices to reduce power consumption and make it easier for consumers to check the time. 
       SUMMARY 
       [0006]    The present invention provides a method and apparatus for displaying the current date and time, or other alphanumeric information, to a user of a cellular telephone or other electronic device. The present invention is useful in cellular telephones and other electronic devices having a keypad. In general terms, the invention comprises a segmented LED display that is integrated with the keypad of the cellular telephone or other electronic device. The integrated LED display comprises a plurality of light elements disposed to emit light from the spaces bordering the keys of the keypad. A light controller controls the individual light segments to output alphanumeric information to the user. Thus, the same area used for the keypad can also be used as a digital clock or alphanumeric display. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a perspective view of an exemplary cellular telephone. 
           [0008]      FIG. 2  illustrates a keypad for a cellular telephone with an integrated LED display. 
           [0009]      FIG. 3  is a section view of an exemplary keypad with an integrated LED display according to a first embodiment. 
           [0010]      FIG. 4  is a section view of another exemplary keypad with an integrated LED display according to a second embodiment 
           [0011]      FIG. 5  is a functional block diagram illustrating a display controller for controlling the integrated LED display. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    Referring now to the drawings, an exemplary embodiment of the present invention is shown. The invention relates to an electronic device having a keypad with an integrated LED display. The electronic device may, for example, comprise a cellular telephone, smart phone, personal digital assistant, laptop computer, or other type of electronic device including a keypad and display. The exemplary embodiment of the invention described below comprises a cellular phone indicated generally by the numeral  10 . However, those skilled in the art will appreciate that the present invention is useful in a wide variety of electronic devices. 
         [0013]      FIG. 1  shows a cellular phone  10  according to one embodiment of the present invention. Cellular phone  10  comprises a housing  12  that contains the electronic components necessary for transmitting and receiving signals. The cellular phone  10  also includes display  20  and keypad  40  to enable user interaction with the cellular telephone  10 . Display  20  renders visual information for viewing by a user. The display  20  may comprise, for example, a liquid crystal display. The keypad  40  comprises a numeric having a plurality of keys  42 . Display  20  and keypad  40  are disposed on the housing  12  with the keypad  40  below the display  20 . However, the particular arrangement of the display  20  and keypad  40  is not material. Thus, the present invention is not limited to the illustrated arrangement. 
         [0014]    In a conventional cellular telephone, information such as the current date and time is displayed to the user on the display  20 . The present invention provides an alternate means of displaying the current date, time, and/or other alphanumeric information to the user. Referring to  FIG. 2 , keypad  40  includes an integrated LED display  60 . LED display  60  comprises a plurality of light elements  62  arranged to emit light from spaces bordering the keys  42  of the keypad  40 . The light elements  62  collectively form a segmented, LED display  60  for displaying alphanumeric characters. The LED display  60  can display any type of alphanumeric information. For example, LED display  60  can be used to display the date and/or time of day, biometric data such as pulse rate or blood pressure levels, or ambient conditions such as the current temperature or barometric pressure. If cellular telephone  10  includes a pedometer (not shown), the distance or count generated by the pedometer may be output to the LED display  60 . 
         [0015]      FIG. 3  provides a section view of an exemplary keypad assembly with an integrated LED display  60 . The keypad assembly comprises a flexible keypad  40  having a plurality of keys  42  formed thereon. Keypad  40  overlies a printed circuit board  50  having contact pads  52  on an upper surface thereof. The keys  42  of the keypad  40  align with a corresponding set of contact pads  52  on the printed circuit board  50 . In the exemplary embodiment shown in  FIG. 3 , each key  42  includes an electrically conductive element  44 . When a key  42  is pressed, the conductive element  44  makes contact with a corresponding contact pad  52  on the printed circuit board  50  to generate an electrical signal that can be detected by a conventional keypad controller (not shown). 
         [0016]    The integrated display  60  comprises a plurality of light elements  62  that are surface mounted to the upper surface of the printed circuit board  50 . While described herein as an LED display  60  with LED light elements  62 , it will be appreciated that any type of light elements  62  may be used for the integrated display  60 . The light elements  62  are elongated and disposed along the sides of the keys  42  to form a segmented LED display  60  that is similar to the display of a digital clock. The light elements  62  emit light through slots  46  in the keypad  42 . The light emitted by the light elements  62  passes through respective lenses  14  on the housing  12 , which are disposed, adjacent the keys  42  of the keypad  40 . The light elements  62  and lenses  14  are located in the spaces bordering the keys, and are arranged to function as a segmented display  60 . 
         [0017]      FIG. 4  illustrates another exemplary keypad assembly with an integrated LED display  60 . In this embodiment, a flex circuit  70  having a plurality of raised domes  72  is interposed between the flexible keypad  40  and the circuit board  50 . Each dome  72  aligns with the corresponding key  42  on the keypad  40 . The domes  72  provide a tactile feedback to the user when a key  42  is fully pressed. Each of the raised domes  72  has an electrically conductive element  74  that aligns with contact pads  52  on the printed circuit board  50 . When a key  42  is pressed, the contact element  74  of the dome  72  makes contact with a corresponding contact pad  52  on the printed circuit board  50  to generate an electrical signal that can be detected by a conventional keypad controller (not shown). 
         [0018]      FIG. 5  illustrates a controller for controlling the segmented LED display  60 . Information for display is output from a main control unit  90  to a light controller  80 . Light controller  80  includes a decoder  82  that converts the alphanumeric characters output from the main control unit into control signals for controlling the individual light elements  62  of the LED display  60 . Decoder  82  may comprise a conventional 7-digit decoder. The control signals output from the decoder  82  are supplied to an LED driver circuit  84 , which generates drive signals to illuminate the light elements  62  responsive to the control signals from the decoder  82 . 
         [0019]    The present invention provides an alternative method and apparatus for displaying alphanumeric information, such as the date and time using a segmented display  60  that is integrated with a keypad  40 . The LED display  60  consumes less power than would a conventional LCD display. Also, the LED display  60  can be seen even in some electronic devices where the main LCD display  20  is covered, turned off, or in sleep mode. These advantages are realized without any additional space requirements, since the light emits through the gaps between the keys  42  of the keypad  40 . 
         [0020]    The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.