Patent Publication Number: US-2011059724-A1

Title: hand-portable electronic device for verifying an input test sequence of characters against a predetermined sequence of characters

Description:
TECHNICAL FIELD 
     Embodiments of the invention relate to a hand-portable electronic device for verifying an input test sequence of characters against a predetermined sequence of characters and a security method for a hand-portable electronic device. 
     BACKGROUND OF THE INVENTION 
     Currently hand-portable electronic devices use security methods to restrict access to the device or one or more of its functions. For example, some current mobile cellular telephones may be configured so that a user must enter a security PIN code when the device is switched on in order to use the device. 
     Typically such a device has a memory that stores a security word as a predetermined sequence of characters, typically numbers. When the telephone is switched on, the user inputs a sequence of digits using the numeric keypad of the mobile telephone. As each digit is entered a ‘*’ is displayed on a display. When the user has finished entering the sequence she selects a function key and the mobile telephone verifies the user input sequence of characters against the stored predetermined sequence of characters. If verification is successful access to the device is allowed. If verification is unsuccessful access to the device is denied. 
     BRIEF SUMMARY OF THE INVENTION 
     According to one embodiment of the present invention there is provided a hand-portable electronic device comprising: a memory for storing a security word as a predetermined sequence of characters; a rotator, having a tactile surface arranged for tactile actuation by a user, and mounted for rotation about an axis; feedback means separate from the rotator for providing feedback to a user as the rotator is rotated; conversion means for converting each rotation of a sequence of rotations of the rotator into a character of a corresponding ordered test sequence of characters; and verification means for verifying the test sequence of characters against the predetermined sequence of characters. 
     According to one embodiment of the present invention there is provided a security method for a hand-portable electronic device comprising a rotator, the method comprising: a user making an ordered sequence of rotations of the rotator; providing at the device, separately from the rotator, feedback to the user as the rotator is rotated during the ordered sequence of rotations; and verifying whether the ordered sequence of rotations made by the user corresponds to a predetermined ordered sequence of rotations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the present invention reference will now be made by way of example only to the accompanying drawings in which: 
         FIG. 1  illustrates a hand-portable electronic device  10 ; 
         FIGS. 2A and 2B  schematically illustrate one example of a rotator input device  30  in cross-section and plan views; and 
         FIGS. 3A ,  3 B,  3 C and  3 D illustrate visual feedback provided to the user by the display  16 . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENT(S) OF THE INVENTION 
     In embodiments of the invention, a user can perform a security method at an electronic device  10  by making an ordered sequence of rotations of the rotator  32 . The device  10  provides separately from the rotator  32 , feedback to the user as the rotator  32  is rotated during the ordered sequence of rotations. There is verification whether the ordered sequence of rotations made by the user corresponds to a predetermined ordered sequence of rotations. This verification may occur at the device  10 . 
       FIG. 1  illustrates a hand-portable electronic device  10  comprising: a memory  12 , a user input  20 , an audio output device  14 , a display output device  16  and a processor  18 . The processor  18  is connected to receive control inputs from the user input  20  and to provide respective control signals to the audio output device  14  and the display  16 . The processor  18  is also connected to read from and write to the memory  12 . 
     The audio output device  14  provides an electrically amplified audio output to the user. 
     The memory  12  stores a security word as a predetermined sequence of characters. The predetermined sequence of characters may be specified by the user. 
     The hand-portable electronic device, in this example, is operable as a mobile cellular telephone. In other examples, the hand-portable electronic device does not have this functionality. The electronic device  10  additionally comprises a cellular radio transceiver  13  connected to the processor  18  that enables communication in a cellular radio telecommunications network (not shown). 
     The user input  20  comprises a rotator input device  30  and additional function keys  22 . The rotator input device  30  provides a first control input  31  to the processor  18  and the function keys  22  provide second control inputs  23  to the processor  18 . 
     The rotation input device  30  comprises a user-rotatable rotator. Rotation of the rotator varies, in a continuous analogue manner, an electrical characteristic of the rotator input device. The electrical characteristic is regularly sampled and quantised to give a quantised value. The quantized value is one of a discrete set of quantised values each of which represents a different rotational position of the rotator. The quantised value is regularly provided to the processor  18  as the time-varying digital first control signal  31 . 
     One example of a rotator input device  30  is schematically illustrated in cross-section in  FIG. 2A  and in plan view in  FIG. 2B . 
     The rotator input device  30 , in this example, replaces a keypad. The rotator input device  30  may be used for data entry such as dialling a telephone number or alphanumeric text entry. Each one of a plurality of different rotational positions of the rotator may correspond to a different input character. 
     The rotator input device  30  comprises a disk-like rotator  32  mounted for rotation about an axis  34  in response to tactile actuation by a user. The disk-like rotator  32  has a circular, flat upper tactile surface  36  that is presented for tactile actuation by a user. 
     In use, the user touches the upper tactile surface  36  with a digit. As the digit is moved, while contacting the upper tactile surface  36 , friction between the user&#39;s digit and the upper tactile surface  36  causes the disk-like rotator to rotate. 
     The circular upper tactile surface  36  has a downwardly depending curved edge  38  that is substantially inaccessible to a user. The axis of rotation  34  is, in this example, substantially perpendicular to the upper tactile surface  36 . The electronic device  10  has a front face  11  and the axis of rotation  34  is, in this example, substantially perpendicular to the front face  11  of the electronic device. 
     The processor  18  provides means for verifying a contemporaneous user-entered sequence of rotations of the rotator (a test sequence) against a predetermined sequence of rotations of the rotator. If the verification is successful, the security procedure has been successfully completed and access is allowed. If the verification is unsuccessful, the security procedure has been unsuccessfully completed and access is denied. Access may be to the general use of the electronic device  10  itself or some function provided by the device. 
     The processor  18  receives the first control signal  31  from the rotator input device  30 . This signal indicates the current rotational position of the rotator  32 . The processor  18  also receives a second control signal  23  from a first function key when it is selected by the user to indicate the termination of a rotation and from a second function key when it is selected to indicate termination of a sequence of rotations. 
     A user rotates the rotator and then presses the first function key to indicate the termination of a rotation. This is repeated for each rotation in the sequence of rotations of the rotator. The user then presses the second function key to indicate the termination of the sequence of rotations. 
     On each termination of a rotation, the processor  18  converts the current quantised value provided by the first control signal  23  to one data value in a set of data values—a “character”. In this example, the conversion is to an ASCII character value. The processor  18  stores the character in the memory  12  as a sequential addition to a test sequence of characters. 
     On termination of the sequence of rotations as indicated by input from the second function key, the processor  18  verifies the user-entered test sequence of characters against the stored predetermined sequence of characters. If the verification is successful, the security procedure has been successfully completed and access is allowed. If the verification is unsuccessful, the security procedure has been unsuccessfully completed and access is denied. Access may be to use the electronic device  10  itself or some function provided by the device. 
     The processor  18 , in addition to performing the security access function described above, also controls the feedback provided to the user during the security procedure. The feedback provided is separate from any noise or tactile feedback provided via the rotator  32  to a user as the rotator  32  is rotated. 
     The processor  18  controls the display to provide visual feedback as illustrated in  FIGS. 3A ,  3 B,  3 C and  3 D. 
     The display is initially controlled by the processor  18  to display an image of a locked safe  40  as illustrated in  FIG. 3A . The image of the safe includes a safe body  42 , a safe door  44  and a safe-dial  46  in the safe door  44 . A current input character  50  is displayed representing the current rotational position of the safe-dial. A sequence of characters  52  is displayed representing the previously entered rotations of the safe-dial  46  in the current sequence. 
     The displayed image, when the rotator  32  is rotated clockwise to its next discrete quantised value, is illustrated in  FIG. 3B . When the processor  18  determines that the first input signal  31  has changed because the rotator has been rotated to its next discrete quantised value the processor  18  converts the new current quantised value to a character and displays that character, rotates the safe-dial in the displayed image of the safe and provides a first audio control signal to the audio output device. 
     In more detail, when the processor  18  determines that the first input signal  31  has changed the processor  18  converts the current quantised value provided by the first control signal  23  to an ASCII character value and displays that value as the current input character. In this example, the displayed current input character  50  is “4”. The value of the displayed current input character increases discretely as the rotator is rotated in a clockwise direction and the value decreases discretely as the rotator is rotated in an anti-clockwise direction. The display, under the control of the processor  18 , provides feedback on the absolute extent of rotation of the rotator as represented by the current input character  50 . 
     In more detail, when the processor  18  determines that the first input signal  31  has changed, the processor  18  converts the change in the first input signal  31  into a change in the displayed image of a safe, so that the safe-dial in the displayed image appears to rotate with and in the same sense as the rotator. The rotational position is illustrated in the Figs using an arrow. 
     In more detail, when the processor  18  determines that the first input signal  31  has changed the processor  18  provides a first audio control signal to the audio output device. This signal controls the audio output device to produce a ‘click’ sound that emulates the sound made when a safe-dial is rotated. Thus the audio output device, under the control of the processor  18 , provides feedback on the relative changes in rotational position of the rotator. Each predetermined gradation in the rotation of the rotator provides a change in the quantised signal that in turn provides a ‘click’. 
     When the processor  18  determines that a rotation has been terminated, it controls the image in the display such that the current input character is transferred into the sequence of characters as the latest character in the sequence of characters  52  as illustrated in  FIG. 3C . 
     If the verification of the security procedure is successful the processor  18  controls the image presented in the display  16  so that it appears as if the safe door is opening as illustrated in  FIG. 3D  and simultaneously controls the audio output device to make a sound similar to a safe door opening. 
     In the above description, the end of a rotation is indicated by a user pushing the first function key. In other implementations, the termination of a rotation may be indicated by a user in a different manner. For example, the user may reverse the direction of rotation of the rotator and the processor  18  may be arranged to detect a reversal and take the quantised value before the reversal as the input value at the termination of the rotation. For example, the user may pause the movement of the rotator e.g. for greater than 0.5 seconds and the processor  18  may be arranged to detect such a pause and take the quantised value at the pause as the input value at the termination of the rotation. 
     Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the spirit and scope of the invention as claimed. For example although a disk-like rotator is described other shapes of rotators may be used. For example, the rotator may have a wheel-like shape or a barrel-like shape where the user actuates the curved surface of the rotator. For example, although in the described example the verification procedure occurs at the device, it may alternatively occur else where. For example, a remote station may store the security word as a predetermined sequence of characters, the device may send a message to the remote station indicative of the test sequence of characters and the remote station may provide verification means for verifying the received test sequence of characters against the stored predetermined sequence of characters. 
     Whilst endeavoring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.