Abstract:
A mobile phone is provided. The mobile phone comprises a touch panel, a camera, and a processor. The touch panel comprises a touch-sensitive display screen, implementing a plurality of virtual buttons. The camera comprises a camera lens having a view-finding area in relation to the touch panel. The processor, respectively coupled with the touch panel and the camera, switches on the camera in response to receipt of a trigger signal, determines whether a focus of the camera for a subject is shorter than a preset distance, and if so, locks the touch panel.

Description:
RELATED APPLICATIONS 
     Reference is hereby made to the Taiwan patent applications, Ser. No. 97104771, the disclosure of the application is incorporated herein by reference. 
     BACKGROUND 
     The invention relates to mobile phones, particularly to mobile phones with a touch panel and method for controlling the same. 
     This section is intended to introduce the reader to various aspects of art, which may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information process to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     Mobile phones equipped with a touch panel have become popular. However, accidental triggering of functions has become troublesome for users. Specifically, because a receiver is generally positioned above the touch panel, when a user uses the receiver, the touch panel may be touched by the user&#39;s face, ear, fingers, or palm, thus accidentally triggering different functions. Additionally, only a few functions, such as ‘back to the main menu’, use hardware buttons, while a majority uses the touch panel. 
     The described problem becomes more serious for mobile phones with a capacitive touch panel. For a capacitive touch panel, conductive current is generated from capacitive changes caused between an electrode array and a surface of the human body. Accordingly, an operation can be triggered without force being applied on the touch panel. Thus, increasing the sensitivity of the touch panel and increasing the accidental triggering of functions for users. 
     For solving the described problem, a proximity sensor is used in mobile phones equipped with a touch panel. When the proximity sensor detects that a user is picking up the mobile phone and is using the receiver, the touch panel (screen) of the mobile phone automatically switches off, to avoid accidental triggering of functions. When the proximity sensor detects that the ear of the user has separated from the mobile phone earphone, the touch panel (screen) of the mobile phone automatically switches on, and returns to an active status. According to the conventional method, a proximity sensor is required. Thus, increasing manufacturing time and costs. 
     SUMMARY 
     Certain aspects commensurate in scope with the originally claimed invention are set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of certain forms the invention might take and that these aspects are not intended to limit the scope of the invention. Indeed, the invention may encompass a variety of aspects that may not be set forth below. 
     A mobile phone is provided. The mobile phone comprises a touch panel, a camera, and a processor. The touch panel comprises a touch-sensitive display screen, implementing a plurality of virtual buttons. The camera comprises a camera lens having a view-finding area in relation process to the touch panel. The processor, respectively coupled with the touch panel and the camera, switches on the camera in response to receipt of a trigger signal, determines whether a focus of the camera for a subject is shorter than a preset distance, and if so, locks the touch panel. 
     Also provided is a method for controlling a mobile phone. The mobile phone comprises a touch panel and a camera, wherein the touch panel comprises a touch-sensitive display screen implementing a plurality of virtual buttons, and the camera comprises a camera lens. A trigger signal has been received and the camera is accordingly switched on. It is determined whether a focal length of the camera for a subject is shorter than a preset focal length. When the focal length of the camera for the subject is shorter than a preset focal length, the touch pane is locked. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
         FIGS. 1A˜1D  are flowcharts of an embodiment of a method for controlling a mobile phone; 
         FIG. 2  illustrates an embodiment of a mobile phone; and 
         FIG. 3  illustrates a block diagram of an embodiment of a mobile phone. 
     
    
    
     DETAILED DESCRIPTION 
     One or more specific embodiments of the invention are described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve specific developer goals, such as compliance with system-related and business-related constraints, which may vary from one implementation process to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     In the following detailed description, reference is made to the accompanying drawings which form a part hereof, shown by way of illustration of specific embodiments. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense. The leading digit(s) of reference numbers appearing in the figures corresponds to the figure number, with the exception that the same reference number is used throughout to refer to an identical component which appears in multiple figures. It should be understood that the many of the elements described and illustrated throughout the specification are functional in nature and may be embodied in one or more physical entities or may take other forms beyond those described or depicted. 
       FIGS. 1A˜1D  are flowcharts of an embodiment of a method for controlling a mobile phone. The mobile phone comprises a touch panel and a camera, wherein the touch panel comprises a touch-sensitive display screen implementing a plurality of virtual buttons, and the camera comprises a front camera lens. Detailed description of the structure of the mobile phone is provided in  FIG. 2 . 
     Referring to  FIG. 1A , steps S 101  and S 102  represent a phone call being made. In step S 101 , a phone number input by a user has been received. In step S 102 , it is detected that a ‘call’ button has been pressed, and accordingly a signal is generated. The ‘call’ button can be a virtual button on the touch panel. 
     Steps S 103  and S 104  represent a phone call being answering. In step S 103 , an incoming call has been received. In step S 104 , it is detected that a ‘receive’ button has been pressed, and a trigger signal is accordingly generated. The ‘receive’ button can be a virtual button on the touch panel. In addition, the ‘call’ button and the ‘receive’ button can be implemented by the same virtual button. 
     In step S 105 , the camera with a front camera lens (hereinafter referred to as a front camera) has been switched on. 
     Referring to  FIG. 1B , after the front camera has been switched on, the front camera has been switched off (step S 117 ) once a hang up button has been pressed (step S 114 ). The hang up button can be a virtual button on the touch panel. 
     After the front camera has been switched on, the front camera is switch off (step S 117 ), a receiver has been switched off and a speaker has been switched on (step S 116 ), when a hands-free mode function has been activated (step S 113 ). The hands-free mode can be activated by pressing a virtual button (acting as a hands-free mode button) on the touch panel. 
     After the front camera has been switched on, the front camera starts to take pictures (step S 115 ), the receiver has been switched off and the speaker has been switched on (step S 116 ), when a video conference mode button has been pressed (step S 112 ). The video conference mode button can be a virtual button on the touch panel. 
     If none of the buttons, such as the hang up button, the hands-free mode button, and the video conference mode button has been activated, the method proceeds to step S 111 , wherein a light measurement is detected. 
     Referring to  FIG. 1C , in step S 121 , it is determined whether the current light measurement is lower than a preset illumination level, and if so, the method proceeds to step S 125 , otherwise, the method returns to step S 105 . 
     In step S 125 , exposure compensation has been performed. The exposure compensation can be a software exposure compensation process to increase the exposure of the camera, or hardware exposure compensation process to provide more light by a flash or lamp. This procedure is used to avoid a situation in which the light is insufficient for determining a focal length (step S 122 ). 
     In step S 122 , a focal length of the camera for a subject is determined. 
     In step S 123 , it is determined whether the focal length of the camera for the subject is shorter than a preset focal length, and if so, the method proceeds to step S 124 , otherwise, the method returns to step S 105 . The preset focal length is a minimum focal length for the camera. As described, the camera has a front camera lens, i.e., the camera lens and the touch panel face toward the same (roughly the same) direction (referred to as the ‘front’ direction). Accordingly, when the focal length of the subject is shorter then a certain focal length, it can be presumed that the subject is approaching the camera lens and the touch panel. 
     In step S 124 , it is determined that the mobile phone should operate in a communication mode. That is, it is determined that a user is making a call or answering a call when the ‘receive’ button (step S 104 ) or the ‘call’ button (step S 102 ) is pressed, and an object is approaching the touch panel. 
     Referring to  FIG. 1D , in step S 131 , the touch panel is locked. Thus, the virtual buttons on the touch panel cannot be activated to avoid accidental triggering of functions. 
     In step S 132 , the light measurement is determined when the touch panel has been locked. In step S 133 , it is determined whether the light measurement is lower than a preset illumination level. 
     Step S 134  is performed when the light measurement is not lower than the preset illumination level; step S 1331  is performed when the light measurement is lower than the preset illumination level. In step S 1331 , an exposure compensation process is performed. The exposure compensation process can be a software exposure compensation process to increase the exposure of the camera, or a hardware exposure compensation process to provide more light by a flash or lamp. 
     In step S 134 , the touch panel is unlocked. The method then returns to step S 105 . 
     In step S 135 , a focal length of the camera for a subject is determined. In step S 136 , it is determined whether the focal length of the camera for the subject is shorter than a preset focal length, and if so, the method proceeds to step S 131 , otherwise, the method returns to step S 134 . In step S 131 , the touch panel remains in a locked position. In step S 134 , the touch panel is unlocked. 
       FIG. 2  illustrates an embodiment of a mobile phone. Based on a front view, a mobile phone  20  comprises a touch panel  21 , receiver  23 , front camera  25 , and hardware button  27 . 
     The touch panel  21  comprises a touch-sensitive display screen implementing a plurality of virtual buttons. 
     The hardware button  27  implements functions such as ‘back to the main menu’, and other functions are implemented via the virtual buttons on the touch panel  21 . 
     The receiver  23  is positioned above the touch panel  21 . The front camera  25  is positioned on the upper-left or the upper-right of the touch panel  21  (upper-left in  FIG. 2 ). 
     Because the mobile phone  20  has a large touch panel  21  and a receiver  23  is positioned above the touch panel  21 , when a user uses the receiver, the touch panel  21  may be touched by the user&#39;s face, ear, and other parts of the body. 
     According to the method for  FIGS. 1A˜1D , when a user picks up the mobile phone  20  and begins a communication session, the touch panel  21  is automatically locked to avoid accidental triggering of functions. 
       FIG. 3  illustrates a block diagram of an embodiment of a mobile phone. A mobile phone  30  comprises a central processing unit  31 , memory  32 , touch panel  33 , camera  35 , light meter  37 , focusing unit  39 , microphone  34 , speaker  36 , and communication unit  38 . 
     The memory  32  stores a preset illumination level value  321 , an exposure compensation program  323 , and a minimum focal length  325 . In addition, the memory  32  stores operation programs, melody data, telephone numbers, and other data. 
     The touch panel  33  comprises a touch-sensitive display screen implementing a plurality of virtual buttons for receiving operation commands. For example, the virtual buttons on the touch panel  33  comprise: a call/receive button  331 , a hang up button  333 , a hands-free mode button  335 , and a video conference mode button  337 . 
     The camera  35  comprises a front camera lens. Here, the camera  35  is also referred to as a front camera. The camera  35  also has a flash or a lamp (not shown) for providing light. 
     The communication unit  38  connects to an antenna  381 , and transmits and receives signals via the antenna  381 . 
     The microphone  34  receives voice from a user. 
     The speaker  36  emits voice via a receiver or a speaker according to signals received by the communication unit  38 . 
     The central processing unit  31  controls operation of the mobile phone  30  according to operation programs stored in memory  32 . 
     The central processing unit  31  generates a trigger signal when a telephone number is input by a user and the call button has been pressed. In addition, the central processing unit  31  generates a trigger signal when an incoming call has been received and the receive button has been pressed. 
     The central processing unit  31  switches on the camera  35  in response to the trigger signal. 
     After the camera  35  has been switched on, the camera  35  will be switched off in two circumstances. 
     First, the central processing unit  31  switches off the camera  35  when the hang up button has been pressed. Second, the central processing unit  31  switches off the camera  35  and the receiver and switches on the speaker, when the hands-free mode button has been pressed. 
     In addition, the central processing unit  31  directs the camera  35  to start taking pictures, switches off the receiver, and switches on the speaker when the video conference mode button has been pressed. 
     The central processing unit  31  further directs the light meter  37  to determine a light measurement when none of the buttons, such as the hang up button, the hands-free mode button, and the video conference mode button has been activated. In addition, the central processing unit  31  determines whether the light measurement is lower than the preset illumination level value  321 . 
     When the light measurement is not lower than the preset illumination level value  321 , it can be presumed that no object is approaching the touch panel  33  (the light is not obstructed). Thus, the camera  35  keeps on taking pictures and the light meter  37  periodically monitors illumination levels. 
     When the light measurement is lower than the preset illumination level value  321 , such as in a dark environment, it may be difficult to measure the focal length. To avoid this problem, the central processing unit  31  executes an exposure compensation program  323  to increase exposure value of the camera  35 . 
     Meanwhile, the focusing unit  39  determines a focal length of the camera  35  for a subject. Next, the central processing unit  31  determines whether the focal length is shorter than a preset focal length (such as a minimum focal length  325 ). 
     When the focal length is not shorter than a minimum focal length  325 , it can be presumed that there is no object positioned adjacent to the touch panel  33 . Thus, the camera  35  keeps on taking pictures and the light meter  37  periodically monitors illumination levels. 
     When the focal length is shorter than a minimum focal length  325 , the central processing unit  31  determines that the mobile phone is operating in a communication mode. That is, it is determined that a user is making a call or answering a call when the ‘receive’ button or the ‘call’ button has been pressed, and an object is approaching the touch panel. 
     In this situation, the central processing unit  31  locks the touch panel  33 . The virtual buttons on the touch panel  33  are therefore deactivated to avoid accidental triggering of functions. 
     During the locked status of the touch panel, the light measurement is periodically determined by the light meter  37 . Thus, the touch panel  33  can be automatically unlocked in response to an end of a communication session. The central processing unit  31  determines whether the light measurement is lower than the preset illumination level value  321 . When the light measurement is not lower than the preset illumination level value  321 , it can be presumed that the object (such as the user&#39;s face) has separated from the touch panel  33 , and the touch panel  33  is unlocked. When the light measurement is lower than the preset illumination level value  321 , the focusing unit  39  determines a focal length of the camera  35  for a subject, and the central processing unit  31  then determines whether the focal length is shorter than a preset focal length. If the focal length is shorter than a preset focal length, the central processing unit  31  locks the touch panel  33 , otherwise, the central processing unit  31  unlocks the touch panel  33 . 
     As described, using the embodiments of the invention, when a user picks up a mobile phone and uses the receiver, the touch panel of the mobile phone is automatically locked to avoid accidental triggering of functions. 
     While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.