Abstract:
A cell phone prevents inadvertent dialing or answering of the cell phone by detecting a low light condition consistent with the phone being in a pocket, purse or the like. The ability to use the phone unencumbered in low light situations is provided by using the low-light detection not to disable the phone but to cause a user prompt that requests a user decision on rejecting the phone activity. The user input is tailored to a particular predetermined button for either condition to ensure the results of this prompt are unlikely to be satisfied by an accidental keypress.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. provisional application 61/345,709 filed May 18, 2010 and hereby incorporated by reference. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    - - - 
       BACKGROUND OF THE INVENTION 
       [0003]    The present invention relates generally to portable communication devices and, more particularly, to cell phones and a method of preventing accidental dialing of cell phones. 
       DESCRIPTION OF RELATED ART 
       [0004]    Portable communication devices, such as mobile phones, personal digital assistants, mobile terminals, etc., typically include a keypad that allows data entry by the user including, for example, the dialing of a telephone number to initiate a call. Frequently, such devices provide for shortcut key sequences that permit rapid dialing of pre-stored phone numbers. This latter feature, in particular, raises the possibility of inadvertently dialing valid phone numbers by an accidental pressing of the keys, for example, if the phone is not suitably deactivated before being placed in a pocket or purse or the like. Such unintended dialing of the cell phone may lead to excessive battery wear and potential embarrassment for the user. A similar problem can occur with incoming calls that are inadvertently answered without knowledge of the user. 
         [0005]    Typically such phones have keyboard lock sequences or devices; however, the users may forget to use the sequences. 
         [0006]    For this reason, it is known in the art to monitor the ambient light received by the phone to deduce the whether the phone may be in a pocket or purse or the like as taught by US patent application 2005/0066091 to Tsai. A low ambient light level detected by the phone indicates that the phone is in the user&#39;s pocket or purse causing any key strikes to be disregarded. 
       SUMMARY OF THE INVENTION 
       [0007]    The present inventors have determined that phone “lockout” systems that monitor ambient light can undesirably prevent the use of the phone in possibly critical situations when the phone is being used outside of the purse or pocket, yet in an environment that has low illumination, for example at night. The present invention addresses this defect through a supplemental prompting of the user for an authorization for the phone activity. Overriding the lockout during a predefined window of time allows the phone to be used in its normal manner. By limiting the keystrokes required for the override and the window of time, a trade-off between unintended calls and unintended lockout may be flexibly affected. 
         [0008]    Specifically, in one embodiment, the present invention provides a computer program stored in a non-transient computer medium. The computer program may be executed by a cell phone having a display screen, user input keys, and a light sensor, to detect phone activity on the cell phone indicating at least one of the beginning of an incoming call or outgoing call and, in response to this detection, check ambient brightness in the environment of the cell phone using the light sensor. When the ambient brightness is below a predetermined threshold, the user is prompted with a display on the display screen to process the call or hang up. In response to this prompt, when a key press on the input keys indicates an intent to terminate the phone activity within a predetermined time window, the phone activity is terminated. Alternatively, when a key press on the input keys indicating an intent to process the phone activity is received within the predetermined time window, the phone activity is allowed to complete. Finally, when no keypress is received within the predetermined time window the phone activity is blocked. 
         [0009]    It is thus a feature of at least one embodiment of the invention to provide a simple method of preventing unintended phone calls that can be used with most cell phones having light sensors such as cameras but that ensures operability of the phone in low light, possibly critical, situations. 
         [0010]    The keypress on the input keys indicating an intent to process the phone activity may be a key sequence starting with a key press of only one predetermined key. 
         [0011]    It is thus a feature of at least one embodiment of the invention to permit overriding of the light sensing feature through a keystroke command, without undoing the very purpose of the invention to prevent inadvertent keystrokes from activating a phone. By limiting the time window and the particular key which must be struck the likelihood of inadvertent phone answering is acceptably reduced. 
         [0012]    The display screen may present instructions as to the key sequence necessary to indicate an intent to process the phone activity and an intent to terminate the phone activity. 
         [0013]    It is thus a feature of at least one embodiment of the invention to provide a system that may be used without previous instruction of the user. 
         [0014]    The user input keys may be virtual keys on a display screen having an overlay touchscreen and the program may present the instructions on the display screen as to the key sequence necessary to indicate an intent to process the phone activity by means of text printed on virtual keys. 
         [0015]    It is thus a feature of at least one embodiment of the invention to provide user instructions that may be readily assimilated and viewed in a low light situation. 
         [0016]    The display screen may further indicate whether the phone activity is an outgoing call or an incoming call. 
         [0017]    It is thus a feature of at least one embodiment of the invention to distinguish between incoming calls and accidental outgoing calls which the user may wish to treat differently. 
         [0018]    The cell phone may include a camera and the checking of ambient brightness may take an average of pixels of the camera. 
         [0019]    It is thus a feature of at least one embodiment of the invention to provide a simple method of detecting likelihood that the phone is in a pocket or purse to use of the camera. 
         [0020]    The computer program may include user input keys that are virtual keys on a display screen having an overlay touchscreen. 
         [0021]    It is thus a feature of at least one embodiment of the invention to prevent inadvertent dialing or phone answering which may occur on phones with virtual buttons. 
         [0022]    These particular objects and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is a perspective view of a front and rear surface of a conventional cell phone showing the keypad that may be accidentally activated and two typical camera locations on the front and back of the cell phone; 
           [0024]      FIG. 2  is a block diagram of a typical cell phone system showing a camera communicating with a processor having keyboard entry and associated with a radiofrequency subsystem; 
           [0025]      FIG. 3  is a flow chart of a program that may be executed by the processor of  FIG. 2  to implement the present invention; 
           [0026]      FIG. 4  is a screen display of a phone showing using the program of the present invention presenting virtual buttons for checking the intent of the user during the outgoing phone operation; and 
           [0027]      FIG. 5  is a figure similar to that of  FIG. 4  showing the buttons for checking the intent of the user during an incoming phone operation. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0028]    Referring now to  FIG. 1 , a cell phone  10  may provide for display  12  such as an LCD associated with a keypad  14 . The keypad  14  may have mechanical or membrane type switches that are pressed to enter alphanumeric data into the cell phone, for example, for the purpose of initiating a call, or may have virtual buttons formed by a touchscreen overlying the display  12  and having targets presented on the display  12 . The cell phone  10  may include a camera  16  placed on the front of the cell phone facing the user when operating the keypad  14 , or a camera  18  placed on the back side of the cell phone  10 . 
         [0029]    Referring now to  FIG. 2 , the cell phone  10  may incorporate a processor  20  that may execute a stored program to receive data from the keypad  14  and provide data to the display  12  in conjunction with the initiation of telephone calls by providing data to and receiving data from an RF subsystem  24  communicating with an internal antenna of the type well known in the art. The processor  20  may also receive image data from the cameras  16  or  18  comprised of multiple pixels each having a brightness value and a spatial location. 
         [0030]    Referring now to  FIG. 3 , the processor  20  may execute a stored program  30 , for example an application program downloadable to the cell phone  10 , that may start at process block  34  as activated by the user or according to a boot up routine. Process block  36  of the program  30  detects phone activity in the form of a beginning of an outgoing call or a receiving of an incoming call such as may be detected by monitoring states presented by the phone&#39;s operating system  31  (shown in  FIG. 2 ). The beginning of an outgoing call, for example, may be indicated by pressing of keys for dialing a phone number while the beginning of an incoming call may be detected by a signal from the RF subsystem  24  as is understood in the art. 
         [0031]    At process block  38 , a call direction (in/out) may be detected to start an outgoing service  40  or an incoming service  42  in the cell phone operating system  31 . These services, executed by the normal operating system  31  of the cell phone may activate an incoming display screen indicated by process block  44  or corresponding outgoing display screen indicated by process block  46 . 
         [0032]    At process block  50 , a brightness of the ambient environment of the cell phone may be determined by interrogation of the cell phone camera  16  or  18 . This interrogation may read an image from the cell phone camera and averaged brightness values of the pixels to deduce a brightness value for the ambient environment of the cell phone. At process block  52 , this brightness value is compared to a brightness threshold selected so that a brightness below the threshold is a low light condition likely to be experienced when the phone is in a pocket or purse and a brightness above the threshold is likely to occur when the phone is in the user&#39;s hand or on a table or the like. 
         [0033]    Such low light conditions can also occur when the phone  10  is out of the pocket or purse in active use but in a dark environment, for example at night. For this reason, when the threshold section of process block  52  indicates a low light environment, at subsequent process block  54 , the user is prompted determine whether they wish the phone activity detected at process block  36  to be completed. 
         [0034]    Referring momentarily to  FIG. 4 , the prompt provided at process block  54  may consist of different displays depending on the detection of an incoming or outgoing phone call at process block  36 . For an outgoing phone call, possibly accidentally dialed, the display  12  provides two virtual buttons  56  and  58 , with virtual button  56  captioned “Hang up” and virtual button  58  captioned “Allow Call”. The user is thus directly informed as to the necessary button pressing to achieve the desired intent. The display  12  may also indicate that an outgoing call has been intercepted per text caption  60  so that the user can tell that the buttons  56  and  58  refer to an accidental dialing of a number by the user on the cell phone  10 . 
         [0035]    Conversely, for an incoming call that otherwise might be accidentally accepted, display  12  may display virtual buttons  62  and  64 , the former with the phrase “Take Call” and the latter the phrase “Hang up”, these captions instructing the user of the necessary actions that must be taken in this context. Addition text label  66  may be displayed indicating that this is an incoming call which the user may wish to treat differently than the outgoing call. 
         [0036]    Referring again to  FIG. 3 , at process block  70 , if there is no user input within a predetermined time period after the display of the prompt at process block  54  (for example, thirty seconds), the call is terminated as indicated by process block  71  whether it be an incoming call or an outgoing call. Alternatively if there is user input at process block  72  and that input is to hang up, per buttons  56  or  64 , the program  30  again proceeds to terminate the phone activity per process block  71 . 
         [0037]    In the event that the ambient light detected at process block  52  is above the threshold value, the program  30  may proceed to process block  74  at which the phone activity detected at process block  36  is completed (either an incoming call taken or outgoing call dialed). If at process block  72 , after the user prompt of process block  54 , the user indicates that hanging up is not desired (by pressing buttons  58  or  62  shown in  FIGS. 4 and 5 ) the program also proceeds to block  74  for the call to be completed. 
         [0038]    In alternate embodiments of the invention, the determination of whether the phone is in a purse or pocket may evaluate additional image features including (1) an averaging of each pixel value of the image to determine the average light level where low light levels are consistent with being in a pocket; (2) evaluation of the variation in illumination of the pixels of the image or image entry that may be consistent with a low light unfeatured surface such as the interior of a pocket; (3) a low focus image determined by the lack of image sharpness; (4) a regular periodic pattern consistent with fabric; and (4) particular colors or color ranges inconsistent with being in a pocket or pocketbook. Each of these determinations may be used individually or in combination and may be combined with other data such as phone orientation determined from internal accelerometers or the like. These determinations may further be weighted according to empirically derived weighting factors. For this purpose, the display illumination  12  may be changed by either dimming it or flashing it to provide for additional image clues from the immediate environment for example by reflected light. As used herein, the term keypress refers either to the pressing of a mechanical key or the touching or sliding of a virtual key on the cell phone. 
         [0039]    Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper,” “lower,” “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front,” “back,” “rear,” “bottom” and “side,” describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. 
         [0040]    When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0041]    References to “a microprocessor” and “a processor” or “the microprocessor” and “the processor,” can be understood to include one or more microprocessors that can communicate in a stand-alone and/or a distributed environment(s), and can thus be configured to communicate via wired or wireless communications with other processors, where such one or more processor can be configured to operate on one or more processor-controlled devices that can be similar or different devices. Furthermore, references to memory, unless otherwise specified, can include one or more processor-readable and accessible memory elements and/or components that can be internal to the processor-controlled device, external to the processor-controlled device, and can be accessed via a wired or wireless network. 
         [0042]    It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications, are hereby incorporated herein by reference in their entireties.