Patent Publication Number: US-2012026338-A1

Title: Electronic device and display mode control method thereof

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to electronic devices and display mode control methods thereof, more particularly to an electronic device that switches display mode according to a sight line vector. 
     2. Description of the Related Art 
     When not being operated for a predetermined time, a mobile terminal will often enter a power saving mode. Although the conventional power saving method for the mobile terminal satisfies the basic requirement, there is still a need for providing a new power saving control method. 
    
    
     
       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 an electronic device and display mode control method thereof. Moreover, in the drawings, like reference numerals designate corresponding parts throughout several views. 
         FIG. 1  is a schematic view of an electronic device according to an exemplary embodiment. 
         FIG. 2  is a block diagram view of the electronic device of  FIG. 1 . 
         FIG. 3  is a flowchart of a display mode control method implemented in the electronic device of  FIG. 1  according to an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 and 2 , an electronic device  10  according to an exemplary embodiment is illustrated. The device  10  includes an infrared lighting unit  20 , an imaging unit  30 , and a processing unit  40 . 
     The infrared lighting unit  20  illuminates a face or an eye of a person that is using the device  10 . In the embodiment, the lighting unit  20  utilizes two infrared light emitting diodes as light sources. 
     The imaging unit  30  takes an image of the face or the eye that the lighting unit  20  illuminates. The image includes a luminance point produced by reflecting the infrared light on an eyeball. 
     The processing unit  40  includes an image processing module  41 , a calculation module  42 , a determining module  43 , and a control module  44 . 
     The image processing module  41  detects positions of the luminance point and a pupil center according to the image taken by the imaging unit  30 . 
     The calculation module  42  calculates a sight line vector according to the positions of the luminance point and the pupil center. The calculation technology is disclosed in US application entitled “sight line detecting method” (publication number 20090015788). 
     The determining module  43  determines whether the sight line vector points to the device  10 . 
     The control module  44  switches the device  10  between a power saving mode and a normal mode according to a determination from the determining module  43 . That is, if the sight line vector points to the device  10 , the control module  44  switches the device  10  into a normal mode. Otherwise, the control mode  44  switches the device  10  into a power saving mode. 
     Referring to  FIG. 5 , a flowchart of a display mode control method is illustrated. 
     In step S 301 , the infrared lighting unit  20  illuminates the object in front of the device  10 , and the imaging unit  30  takes an image of the object. 
     In step S 302 , the image processing module  41  determines whether the image includes the luminance point. If no, the procedure goes to step S 307  described as below. 
     If yes, in step S 303 , the image processing module  41  detects the positions of the luminance point and the pupil center. 
     In step S 304 , the calculation module  42  calculates the sight line vector according to the positions of the luminance point and the pupil center. 
     In step S 305 , the determining module  43  determines if the sight line vector points to the device. If yes, in step S 306 , the control module  44  switches the device  10  into the normal mode. If no, in step S 307 , the control mode  44  switches the device  10  into the power saving mode. 
     Finally, while the present disclosure has been described with reference to particular embodiments, the description is illustrative of the disclosure and is not to be construed as limiting the disclosure. Therefore, various modifications can be made to the embodiments by those of ordinary skill in the art without departing from the true spirit and scope of the disclosure as defined by the appended claims.