Patent Publication Number: US-2012026385-A1

Title: Electronic device with power saving function and operating method thereof

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to an electronic device with power saving function and an operating method thereof. 
     2. Description of Related Art 
     Power saving solutions for portable electronic devices often adopt standby or sleep states. However, when a portable electronic apparatus is operated for a period of time with no input received, such as during audio or video playback, such power-saving modes may be implemented in spite of the current operation, and the audio or video playback is interrupt. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The components of the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout several views. 
         FIG. 1  is a schematic diagram of an electronic device with power saving function in accordance with an exemplary embodiment. 
         FIG. 2  is a structural diagram of an image obtaining unit of the electronic device  1  of  FIG. 1 . 
         FIG. 3  is a block diagram of the electronic device  1  of  FIG. 1 . 
         FIG. 4  is a flowchart of power-saving mode implementation method for the electronic apparatus of  FIG. 1 . 
         FIG. 5  is a flowchart of power-saving mode recovery method for the electronic apparatus of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a schematic diagram of an electronic device  1  with power saving function (hereinafter “the electronic device”) in accordance with an exemplary embodiment. The electronic device  1  can be, for example, an e-book or a computer. When the power saving function of the electronic device  1  is enabled, and if no user is detected in proximity of the electronic device  1 , a power saving mode, such as standby or sleep state, is implemented. When the electronic device  1  is in the power saving mode, no power is provided to selected components. The electronic device  1  includes an image obtaining unit  2  and an illumination unit  3 . The image obtaining unit  2  acquires images of the objects in a proximal area of the electronic device  1 . The illumination unit  3  provides additional illumination for the image obtaining unit  2  when needed. In this embodiment, the image obtaining unit  2  and the illumination unit  3  are separately mounted outside the electronic device  1 . In other embodiments, the illumination unit  3  can integrated into the image obtaining unit  2 . 
       FIG. 2  is a structural diagram of the image obtaining unit  2  of the electronic device  1  of  FIG. 1 . The image obtaining unit  2  includes an imaging unit  21 , an image sensor  22 , and an A/D converter  23 . The imaging unit  21  is configured for capturing images of a proximal area of the electronic device  1  onto the image sensor  22 . The image sensor  22  is configured for converting the image to electric signals. The A/D converter  23  converts the electric signals to digital signals. The image sensor  22  can be CCD or CMOS. 
       FIG. 3  is a block diagram of the electronic device  1  of  FIG. 1 . The electronic device  1  further includes a processing unit  12 , a data storage  13  and other necessary components (not shown). The processing unit  12  includes a distance measurement module  122 , a computation module  123 , a determination module  124 , and a control module  125 . 
     Once power saving function of the electronic device  1  is enabled, the distance measurement module  122  calculates the distance between the electronic device  1  and any object in a proximal area of the electronic device  1  according to the image obtained by the image obtaining unit  2 , and stores the distance as an original distance to the data storage  13 . The distance measurement module  123  periodically obtains the distance between the object and the electronic device  1 , and stores the distance as a current distance to the data storage  13  after the original distance determined. If there is no object in the proximal area of the electronic device  1 , the distance measurement by the distance measurement module is regarded as infinite. 
     The computation module  123  is configured for computing a difference between the original distance and the current distance. The determination module  124  determines whether the difference between the original distance and the current distance falls within a predetermined range. If the difference between the original distance and the current distance does not fall into the predetermined range, the control module  125  puts the electronic device  1  into power saving mode. If the difference between the original distance and the current distance falls within the predetermined range, the current distance is taken as the original distance and the original distance stored in the data storage  11  is updated accordingly. The predetermined range can be predefined by user input. 
     When the electronic device  1  is in operation, a standard distance range between the electronic device  1  and the object in a proximal area of the electronic device  1  is generated. For example, the standard distance range for the computer is 0-100 cm, and the standard distance range for e-book is 0-50 cm, if the distance between the object and the electronic device  1  falls within the standard distance range, it is assumed that a user is operating or will operate the electronic device  1 , and, conversely, if the distance between the object and the electronic device  1  does not fall into the standard distance range, it can be regarded that no user is present. 
     In another embodiment, if the difference between the original distance and the current distance falls within the predetermined range, the determination module  124  further determines whether the current distance falls within the standard distance range. If the current distance does not fall into the standard distance, the electronic device  1  is put into power saving mode. If the current distance falls within the standard distance range, the computation module  123  takes the current distance as the original distance and the distance measurement module  122  continues obtaining current distance measurements. 
     Once the electronic device  1  is in the power-saving mode, the distance measurement module  122  obtains the distance between the object and the electronic device  1  according to the image periodically obtained by the image obtaining unit  2 . The predetermined module  124  determines whether the distance falls within the standard distance range. If the distance falls within the standard distance range, the control module  125  recovers the electronic device  1  from the power saving mode. 
       FIG. 4  is a flowchart of power-saving mode implementation method for the electronic apparatus of  FIG. 1 . In step S 401 , the distance measurement module  122  obtains the distance between any object in a proximal area of the electronic device  1  and the electronic device  1  according to the image obtained by the image obtaining unit  2 , and stores the distance as the original distance to data storage  13 . 
     In step S 403 , the distance measurement module  123  periodically obtains the distance between the object and the electronic device  1 , and stores the distance as a current distance to the data storage  13 . 
     In step S 404 , the computation module  123  computes the difference between the original distance and the current distance. 
     In step S 405 , the determination module  124  determines whether the difference between the original distance and the current distance falls within the predetermined range. 
     If the difference between the original distance and the current distance does not fall into the predetermined range, in step S 406  the control module  125  puts the electronic device  1  into power-saving mode. 
     If the difference between the original distance and the current distance falls within the predetermined range, in step S  407 , the determination module  124  further determines whether the current distance falls within the standard distance range. 
     If the current distance does not fall into the standard distance, step S 406  is implemented. 
     If the current distance falls into to the standard distance, in step S 408 , the current distance is taken as the original distance, and step S 403  is implemented. 
       FIG. 5  is a flowchart of power-saving mode recovery method for the electronic apparatus of  FIG. 1 . In step S 501 , once electronic device  1  is in power-saving mode, the distance measurement module  122  periodically obtains the distance between the object and the electronic device  1  according to the image obtained by the image obtaining unit  2 . 
     In step S 502 , the predetermined module  124  determines whether the distance falls within the standard distance range. If the distance does not fall within the standard distance range, step S  501  is implemented. 
     If the distance falls within the standard distance range, in step S 503 , the control module  125  recovers the electronic device  1  from the power saving mode. 
     Although the present disclosure has been specifically described on the basis of preferred embodiments, the disclosure is not to be construed as being limited thereto. Various changes or modifications may be made to the embodiment without departing from the scope and spirit of the disclosure.