Abstract:
A device comprising at least a touch screen and a keypad for providing input functions. The keypad is provided with a key lock operation comprising an active state and a inactive state. The active state is adapted to disable at least part of the input functions of the keypad, and the inactive state is adapted to enable the input functions of the keypad. The device also comprises a detector for detecting when a stylus is in proximity with the touch screen; and a key lock activator for setting the key lock into said active state when the detector provides indication of the proximity of the stylus.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a device comprising at least a touch screen and a keypad. The invention also relates to a system comprising a touch screen and a keypad. The invention further relates to a method and a computer program product to be used in processing input information from a touch screen and a keypad.  
       BACKGROUND OF THE INVENTION  
       [0002]     There exist devices comprising a touch screen, which can be used in connection with a display to provide input information to the devices, for example to perform selections among objects shown on the display. Such devices may also comprise a keypad for inputting information by the keys of the keypad. For example, the user of the device may input a text message or a telephone number by the keypad.  
         [0003]     There are some different kind of touch screens available. For example, there are inductive touch screens in which an inductive stylus is used to perform the touch operation. When the inductive stylus approaches the touch screen the detection circuitry detects the stylus, determines the touching point of the stylus and provides e.g. coordinate information on the touching point. The coordinate information of the touching point can then be used to determine which operation relates to the touching point.  
         [0004]     There are also optical, acoustical, resistive and capacitive touch screens, for example. These kind of touch screens do not usually need a special stylus to be used but, for example, a finger can normally be used as the stylus.  
         [0005]     There exists a problem with usability in devices equipped both with a touch screen and a keypad. It may happen that when the user tries to touch the touch screen to perform some touch based action either with finger or stylus he or she simultaneously presses some key or keys in the keypad. This may effect initiation of an unintentional action.  
         [0006]     There are some ways to avoid this usability problem for example by ensuring that the device size is big enough, by placing the touch screen and keys of the keypad not close to each other, therefore decreasing the probability to press the keys unintentionally. Another solution to avoid the aforementioned problem is to use a longer stylus, which can, however, make the pointing more difficult.  
         [0007]     The so called key lock operation is known by which the keypad of a device can be disabled and enabled. The key lock can be activated and deactivated by pressing a certain key or a key combination of the keypad. This may be cumbersome because every time the user wants to use the touch screen he or she should manually activate the key lock if it is not active and if the user wants the key lock to be activated, for example, to avoid erroneous key presses.  
         [0008]     The European patent application EP 1 284 450 discloses a method for preventing unintended touch pad input due to accidental touching. In the method the similar key lock operation can be activated to disable at least some of the touch screen functions. The key lock is activated and deactivated by a certain key or by a certain key combination wherein by pressing the certain key or key combination the status of the key lock is changed i.e. the key lock is activated or deactivated. However, the key lock does not effect the operation of the key pad itself wherein if the user wants to lock the keypad he or she has to do it manually by pressing a certain key or key combination on the keypad.  
       SUMMARY OF THE INVENTION  
       [0009]     In the present invention there is provided a solution for reducing the effects of unintentional touching of a keypad when operating the touch screen. The invention is based on the idea that the key lock of the keypad can be activated while beginning the operation of the touch screen. The activation may be based on detecting when the stylus of the touch screen is in proximity of the touch screen or detecting when the stylus such as a finger touches the touch screen or any other operation that is related to the touch screen operation. The status of the key lock of the keypad may be indicated on the screen. The feature can be switched off, because some features or actions of the device may require simultaneous use of the keypad and the touch screen.  
         [0010]     According to a first aspect of the present invention there is provided a device comprising at least 
        a touch screen;     a keypad for providing input functions, the keypad being provided with a key lock operation comprising an active state and a inactive state, the active state being adapted to disable at least part of the input functions of the keypad, and the inactive state being adapted to enable the input functions of the keypad;     a detector for detecting when a stylus is in proximity with the touch screen; and     a key lock activator for setting the key lock into said active state when the detector provides indication of the proximity of the stylus.        
 
         [0015]     According to a second aspect of the present invention there is provided a system comprising at least 
        a touch screen;     a keypad for providing input functions, the keypad being provided with a key lock operation comprising an active state and a inactive state, the active state being adapted to disable at least part of the input functions of the keypad, and the inactive state being adapted to enable the input functions of the keypad;     a detector for detecting when a stylus is in proximity with the touch screen; and     a key lock activator for setting the key lock into said active state when the detector provides indication of the proximity of the stylus.        
 
         [0020]     According to a third aspect of the present invention there is provided a method comprising at least 
        activating a key lock of a keypad, the keypad being provided with a key lock operation comprising an active state and a inactive state, in which active state at least part of input functions of the keypad being disabled, and in which inactive state the input functions of the keypad being enabled;     detecting when a stylus is in proximity with the touch screen; and     setting the key lock into said active state when the proximity of the stylus is detected.        
 
         [0024]     According to a fourth aspect of the present invention there is provided a computer program product comprising machine executable steps for 
        activating a key lock of a keypad, the keypad being provided with a key lock operation comprising an active state and a inactive state, in which active state at least part of input functions of the keypad being disabled, and in which inactive state the input functions of the keypad being enabled;     detecting when a stylus is in proximity with the touch screen; and     setting the key lock into said active state when the proximity of the stylus is detected.        
 
         [0028]     The invention improves the usability of small electronic devices and reduces the effects of unintentional actions for example when the user, while touching the touch panel, unintentionally presses one or more keys of the keypad of the device. 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0029]     In the following the present invention will be described in more detail with reference to the appended drawings in which  
         [0030]      FIG. 1  depicts a device according to an example embodiment of the present invention as a simplified block diagram,  
         [0031]      FIG. 2  depicts an example of a user interface of a device according to an example embodiment of the present invention,  
         [0032]      FIG. 3  shows as a flow diagram the method according to an example embodiment of the present invention, and  
         [0033]      FIG. 4  depicts another example of a user interface of a device according to an example embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0034]     An example of a device  1  and a system according to the present invention is shown in  FIG. 1 . The device  1  is, for example, a portable device such as a communicator, a personal digital assistant (PDA), a smart phone etc. but the invention is not solely restricted to these kinds of devices. The device  1  comprises a touch screen  2  which includes a touch panel  2 . 1 , a display  2 . 2  (also known as a screen), and a touch panel controller  2 . 3 . The touch pointing is handled with stylus  8  or with a finger. The device  1  also comprises a keypad  3 , a processor  4  and a memory  5 . The device  1  may also comprise a transmitter/receiver  6  for communicating with other devices (not shown) directly and/or via a network (not shown). It should be noted here that the device  1  may comprise more than one processor, display, keypad, memory, transmitter/receiver, etc.  
         [0035]     In the following the operation of an example method of the present invention will be described in connection with the device  1  of  FIG. 1 . The reference is also made to the flow diagram of  FIG. 3  showing some of the steps of the method according to an example embodiment of the present invention. When the device  1  is powered up, the touch panel controller  2 . 3  initializes the touch panel  2 . 1 . The touch panel  2 . 1  may need a calibration to calibrate the touch panel  2 . 1  with the display  2 . 2 . The processor  4  can also perform initialization operations to the device  1 , for example, to set the status of the key lock (block  301  in  FIG. 3 ), send information on the display  2 . 2 , perform a registration process to a wireless network by the transmitter/receiver  6 , etc. After the initialization is completed some information can be shown on the display and the user can begin to use the device  1 . It is assumed here that the key lock of the keypad  3  is deactivated in the beginning of the operation of the device  1  but it may also be activated.  
         [0036]     The touch panel controller  2 . 3  checks  302  at intervals or based on interrupts the status of the touch panel to determine whether the touch panel  2 . 1  is touched by a stylus  8  ( FIG. 2 ) or not. The way the touch can be detected depends on the type of the touch panel  2 . 1 . In addition to the touch detection some touch panels  2 . 1  can also detect when the stylus is in proximity of the touch panel  2 . 1 . For example, by inductive touch panels it may be possible to detect an inductive stylus even when the stylus is approximately several centimeters away from the surface of the touch panel  2 . 1 . This proximity detection can be used as an indication that the stylus is approaching the touch panel  2 . 1 .  
         [0037]     When the touch panel controller  2 . 3  detects that the stylus  8  touches the touch panel  2 . 1  the touch panel controller  2 . 3  sends information on the touch to the processor  4 . The information may include coordinates of the touch or other information of the location of the touch on the touch panel  2 . 1 . The processor  4  determines that there is a touch on the touch screen wherein the key lock of the keypad  3  should be activated unless the activation of the key lock is prevented, for example, by the user. The processor  4  may examine  303  before activating the key lock whether the key lock is already active, wherein it is not necessary to change the status of the key lock. The status of the key lock is stored in the memory  5  for a later use. The status of the key lock may also be indicated on the display  2 . 2  for example by a symbol  203  ( FIG. 2 ) or by some text. It is also possible that the status of the key lock is only indicated when the key lock is either active or inactive. The other status of the key lock can then be determined by the absence of the indication  203 .  
         [0038]     In an example embodiment of the present invention it is possible to prevent the activation of the key lock. Therefore, a key lock enablement indicator is provided e.g. in the memory  5 . The processor  4  examines  304  the value of the key lock enablement indicator to determine whether the key lock can be activated or not. If it is determined that the key lock can be activated, the processor  4  sets  305  the key lock active.  
         [0039]     The processor  4  also examines, when necessary, the location information received from the touch panel controller  2 . 3  and compares it with the information shown on the display  2 . 2 . There may be activation areas  201  ( FIG. 2 ) shown on the display  2 . 2  to activate the function connected with the activation area. When the processor  4  detects that the coordinates of the touch are within an activation area  201  the processor  4  examines which function is connected with that activation area and begins the processing of the function. The function can be, for example, setting up a call, receive a call, execution of an application etc. It is also possible that some of the activation areas are meant for inputting free-form information such as drawing a picture, handwriting a note etc.  
         [0040]     The touch panel controller  2 . 3  can continuously provide information of the touch when the stylus is pressed on the touch panel  2 . 1  or is in proximity with the touch panel  2 . 1 . The coordinate information of the touch can be updated when the location of the touch changes.  
         [0041]     In an example embodiment of the present invention the key lock is activated all the time the touch is detected. When the touch panel controller  2 . 3  detects that the stylus is not touching the touch panel  2 . 1  any more or is diverged from the proximity of the touch panel  2 . 1  the touch panel controller  2 . 3  may provide an indication of the end of the touch to the processor  4 , or the touch panel controller  2 . 3  stops transmitting coordinate information to the processor  4 . In the first alternative, the processor  4  detects the indication of the end of the touch and can use this information to update the status of the key lock. In the latter alternative a delay has been defined for the processor  4  wherein if the key lock is active  306  and no coordinate information is received from the touch panel controller  2 . 3  during the delay the processor  4  deduces  307  that the stylus is not touching the touch panel anymore. When the processor  4  has detected the end of the touch the key lock of the key pad  3  may be deactivated  308 . However, if the user of the device  1  has manually activated the key pad for example by pressing certain keys of the keypad  3  the deactivation of the key lock by the processor  4  may have been prevented. In such a situation the user may not want that the processor  4  deactivates the key lock but the user may wish to manually deactivate the key lock at a later stage.  
         [0042]     When the touch panel controller  2 . 3  can detect the proximity of the stylus before the stylus is in contact with the touch panel  2 . 1  the proximity detection can be used by the processor  4  to activate the key lock of the keypad  3 . Therefore, the processor  4  need not wait for the coordinate information thus allowing the activation of the key lock at an earlier stage compared with the above described embodiment.  
         [0043]      FIG. 2  shows an example of a user interface of the device  1 . The user interface comprises the touch screen  2  and the keypad  3 . On the display  2 . 2  some information can be depicted to the user. For example, activation areas  201  and information  202  relating to an application being executed in the device  1  can be shown on the display  2 . 2 .  
         [0044]     It should be noted here that there can be some alternatives on the styluses  8  which can be used with the touch screen  2 . Some touch screens require a certain kind of stylus (e.g. the inductive touch screen) while other kind of touch screens may function properly with many different kinds of styluses. Further, the term “touch” need not necessarily mean that the stylus really touches the surface of the touch panel  2 . 1  but the touch may also be detected when the stylus is close to the surface but not touching it. For example, in some embodiments the touch can be detected when the stylus is from few millimeters to several centimeters above the surface of the touch panel  2 . 1 . There may also be a protective and at least partly transparent cover (not shown) on the surface of the touch panel  2 . 1  wherein the stylus  8  touches the cover but not the touch panel  2 . 1 .  
         [0045]     In another example embodiment of the present invention a certain detection area  204  is defined on the touch screen  2  for the detection of the proximity of the stylus  8 . An example of a user interface in which such detection area  204  is defined is depicted in  FIG. 4 . The proximity of the stylus  8  is to be detected when the stylus  8  is in proximity with the detection area  204  of the touch screen  2  and the key lock can be activated on the basis of the detection. If the stylus  8  is in proximity of the touch screen  2  but outside of the detection area  204  the proximity indication is not provided or, if the proximity indication is provided, it is not used to indicate the proximity of the stylus  8 . This kind of implementation can be used, for example, to restrict the area of the touch screen  2  on which the stylus  8  can be used for performing touch based operations. The detection area  204  can be defined in several different ways. For example, the detection area  204  can be predefined in the device  1 , or the detection area  204  can be defined by an application running in the device  1 , by a user of the device  1 , or by an operating system of the device  1 , etc. In these example embodiments of the invention the detection area  204  is not necessarily defined on a fixed part of the touch screen  2  but the location of the detection area  204  can vary in different situations. For example, if the detection area  204  is defined by an application which produces different kinds of outlooks on the display  2 . 1 , the location of the detection area  204  may vary according to the outlook produced by the application. This kind of approach is useful inter alia when different outlooks comprise different kinds of selectable objects presented to the user on the display  2 . 1  and the location of the selectable objects may be different in different outlooks.  
         [0046]     The present invention is not solely limited to the above described embodiments but it can be varied within the scope of the appended claims.