Abstract:
A method of updating luminance of light emitting elements of a portable electronic device according to ambient light intensity sensed by image capturing units of the portable electronic device is proposed. The method includes sensing ambient light intensities using light sensors of the image capturing units, determining the luminance of the light emitting elements of the portable electronic device according to the ambient light intensities sensed by the light sensors of the image capturing units, controlling the light intensity of the light emitting elements of the portable electronic device according to the determined luminance.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a method of updating luminance of light emitting elements, and more particularly, to a method of updating luminance of light emitting elements according to ambient light intensities sensed by image capturing units of a portable electronic device.  
         [0003]     2. Description of the Prior Art  
         [0004]     Portable electronic devices capable of taking pictures are getting more and more popular, and the function of taking pictures can be accomplished by the use of a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) sensor of a prior art portable electronic device. A displaying screen utilized by a prior art portable electronic device also uses more colors than before. The input keys of the prior art portable electronic devices also comprise light emitting diodes for supporting the function of taking pictures, and the function of taking pictures leads to a huge power consumption. Under a limited power supply, the efficient utilization and management of power is becoming more important also. In order to minimize the user of power, various ambient light sensors are provided for sensing ambient light intensities of a prior art portable electronic device. Then the light intensities of the backlight of the displaying screen and the light emitting diodes around the input keys of the prior art portable electronic device are updated automatically according to the sensed ambient light intensities. Therefore, although there is a limited power supply, the power supply time is lengthened, and the power consumption is also decreased by decreasing the light intensities of the backlight of the displaying screen and the light emitting diodes around the input keys of the prior art portable electronic device. However, the ambient light sensors utilized by the prior art portable electronic device increase the cost of the required hardware, require additional space, and increase the design time of the portable electronic devices.  
       SUMMARY OF THE INVENTION  
       [0005]     A method of updating luminance of light emitting elements of a portable electronic device according to ambient light intensity sensed by image capturing units of the portable electronic device comprises sensing ambient light intensities using light sensors of the image capturing units, determining the luminance of the light emitting elements of the portable electronic device according to the ambient light intensities sensed by the light sensors of the image capturing units, and controlling the light intensity of the light emitting elements of the portable electronic device according to the determined luminance of the light emitting elements of the portable electronic device.  
         [0006]     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a diagram of the reverse side of a portable electronic device utilizing the present invention method and having the function of taking pictures.  
         [0008]      FIG. 2  is an amplified diagram of the image capturing unit of  FIG. 1 .  
         [0009]      FIG. 3  is a diagram of the front side of the portable electronic device of  FIG. 1 .  
         [0010]      FIG. 4  is a flowchart of utilizing the present invention method on the portable electronic device of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION  
       [0011]     The present invention method can be applied on any electronic devices capable of taking pictures, and the function of taking pictures is accomplished by a charge coupled device or a complementary metal oxide semiconductor sensor of the electronic device. The method is an automatic luminance control procedure cooperating with the system of a portable electronic device for automatically detecting ambient light intensities. Therefore, it is not necessary to update the circuits in the electronic device or to add any hardware such as ambient light sensors to the electronic device. The light intensities of the backlight of the displaying screen and the light emitting diodes around the input keys of the portable electronic device are thus efficiently and automatically updated. However, besides running the automatic luminance control procedure of the present invention with software, there are still other ways to run the automatic luminance control procedure in the present invention. For example, running the automatic luminance control procedure with firmware or hardware cooperating with software. A portable electronic device utilizing the automatic luminance control procedure of the present invention is utilized to reach the aim of decreasing power consumption by updating the light intensities of light emitting elements and of saving the additional hardware cost needed for ambient light sensors.  
         [0012]     Please refer to  FIG. 1 , which is a diagram of the reverse side of a portable electronic device  100  utilizing the present invention method and having the function of taking pictures. As shown in  FIG. 1 , the portable electronic device  100  comprises a housing  102 , an image capturing opening  104  disposed on the housing  102 , and an image capturing unit  106  beneath the housing  102  and the image capturing opening  104 . The image capturing unit  106  comprises a plurality of light sensors  108 . Since the image capturing unit  106  is beneath the housing  102  and the image capturing opening  104 , the image capturing unit  106  is illustrated with dotted lines as are the plurality of light sensors  108 . The locations of the plurality of light sensors  108  on the image capturing unit  106  correspond to pixels. It represents that a light intensity detected by single light sensor  108  corresponds to the light intensity of a pixel. Please refer to  FIG. 2 , which is an amplified diagram of the image capturing unit  106  of  FIG. 1 . As shown in  FIG. 1  and  FIG. 2 , the plurality of light sensors  108  are disposed on the image capturing unit  106  for sensing ambient light intensities of the image capturing opening  104 . However, the number of the light sensors  108  is not limited by the embodiment shown in  FIG. 2  and can be updated according to requirements.  
         [0013]     Please refer to  FIG. 3 , which is a diagram of the front side of the portable electronic device  100  of  FIG. 1 . As shown in  FIG. 3 , the portable electronic device  100  further comprises an input key panel  110  disposed on the housing  102 , and a displaying screen  116  disposed on the housing  102  and having a backlight. The input key panel  110  comprises a plurality of input keys  112  and a plurality of light emitting diodes  114 . Each of the plurality of light emitting diodes  114  corresponds to an input key  112  and is disposed near the input key  112  and beneath the input key panel  110 . Since the plurality of light emitting diodes  114  are disposed beneath the input key panel  110 , the plurality of light emitting diodes  114  are illustrated with dotted lines as shown in  FIG. 3 . The input keys  112  are generally made up of light-transmitting materials and are drawn with characters. Therefore, the drawn characters on the light-transmitting input keys  112  can be seen clearly through with the light emitted from the light emitting diodes  114 . Since the characters are seen clearly, a user is able to input instructions precisely through the input key panel  110  to the portable electronic device  100 . The displaying screen  116  is utilized to display messages of the portable electronic device  110 . When the light intensities of the input key panel  110  and the backlight of the displaying screen  116  are darker than the ambient light intensities of the portable electronic device  100 , the input key panel  110  and the displaying screen  116  cannot be seen clearly. When the light intensities of the input key panel  110  and the backlight of the displaying screen  116  are brighter than the ambient light intensities of the portable electronic device  100 , unnecessary power consumption by the portable electronic device  100  is generated. Therefore, the present invention provides a method of dynamically updating the light intensities of the input key panel  110  and the backlight of the displaying screen  116  so that the light intensities of the input key panel  110  and the backlight of the displaying screen  116  are in harmony with the ambient light intensities of the portable electronic device  100 . Therefore, the input key panel  110  and the displaying screen  116  are seen clearly without generating unnecessary power consumption.  
         [0014]     Please refer to  FIG. 4 , which is a flowchart of utilizing the present invention method on the portable electronic device  100  of  FIG. 1 . As shown in  FIG. 4 , the present invention method comprises:  
         [0015]     Step  200 : Starting the automatic luminance control procedure;  
         [0016]     Step  204 : Retrieving a plurality of ambient light intensities detected by the plurality of light sensors  108  of the image capturing unit  106 , and calculating the average of the plurality of ambient light intensities;  
         [0017]     Step  206 : Updating the light intensity of the backlight of the displaying screen  116  of the portable electronic device  100  according to the average light intensity calculated in step  204 ;  
         [0018]     Step  208 : Updating the light intensities of the light emitting diodes  114  of the input key panel  110  according to the average light intensity calculated in step  204 ; and  
         [0019]     Step  210 : Finishing the automatic luminance control procedure.  
         [0020]     In step  200 , the automatic luminance control procedure of the portable electronic device  100  in the present invention starts. The automatic luminance control procedure is utilized to dynamically update the light intensities of the input key panel  110  and the backlight of the displaying screen  116  according to variable ambient light intensities of the portable electronic device  100 . However, a user may also operate a manual luminance control procedure so that the light intensities of the backlight of the displaying screen  116  and the input key panel  110  are updated manually according to requirements of the user. Under the manual luminance control procedure, steps  204 ,  206 ,  208 , and  210  do not need to be performed.  
         [0021]     In step  204 , the ambient light intensities around the image capturing opening  104  are detected using the plurality of light sensors  108  of the image capturing unit  106 . Therefore, the detected ambient light intensities are regarded as standards of updating the light intensities of the backlight of the displaying screen  116  and the input key panel  110 . The average of the detected ambient light intensities is regarded as a reference ambient light intensity of the portable electronic device  100  for running steps  206  and  208 .  
         [0022]     In step  206 , the reference ambient light intensity retrieved in step  204  is utilized to update the light intensity of the backlight of the displaying screen  116  of the portable electronic device  100  so that the light intensity of the backlight of the displaying screen  116  is in harmony with the ambient light intensities of the portable electronic device  100 . Therefore, the messages shown on the displaying screen  116  are clearly seen through the appropriate light intensity of the backlight of the displaying screen  116 . Unnecessary power consumption by the displaying screen  116  is also prevented through the use of the appropriate light intensity of the backlight of the displaying screen  116 .  
         [0023]     In step  208 , the light intensities of the light emitting diodes  114  of the input key panel  110  are updated according to the reference ambient light intensity retrieved in step  204  also. Therefore, the light intensities of the light emitting diodes  114  of the input key panel  110  are in harmony with the ambient light intensities of the portable electronic device  100 . Thus, the user will not push the wrong keys due to dark light intensities of the input key panel  110 . The power consumption of the light emitting diodes  114  is also prevented through the appropriate light intensities of the light emitting diodes  114 .  
         [0024]     The order of running steps  206  and  208  is not limited to the order shown in  FIG. 4 . Therefore, steps  206  and  208  may also be run in an order other than the order of  FIG. 4 .  
         [0025]     In step  210 , the automatic luminance control procedure is finished. Further instructions from the portable electronic device  100  are also waited for continuously for dynamically updating the light intensities of the light emitting diodes  114  of the input key panel  110  and the backlight of the displaying screen  116  according to the ambient light intensities of the portable electronic device  100 . Therefore, the light intensities of the light emitting diodes  114  of the input key panel  110  and the backlight of the displaying screen  116  are in harmony with the ambient light intensities of the portable electronic device  100  continuously.  
         [0026]     The present invention provides a method of updating the light intensities of light emitting elements according to the ambient light intensities sensed by the image capturing unit of a portable electronic device. Therefore, the light intensities of the backlight of the displaying screen and the light emitting diodes of the key input panel are dynamically updated and are in harmony with the variable ambient light intensities of the portable electronic device. Moreover, the characters on the input keys of the input key panel and the messages on the displaying screen are clearly seen since the light intensities of the light emitting diodes of the input key panel and the backlight of the displaying screen are not darker than the ambient light intensities of the portable electronic device. Unnecessary power consumption by the light emitting diodes of the input key panel and the backlight of the displaying screen is also prevented since the light intensities of the light emitting diodes of the input key panel and the backlight of the displaying screen are not much brighter than the ambient light intensities of the portable electronic device. Furthermore, since the automatic luminance control procedure of the present invention is run by using software installed on the portable electronic device in the present invention, the aim of appropriately controlling the luminance of the light emitting elements is reached by updating the software installed on a prior art portable electronic device or by using hardware and firmware capable of running the automatic luminance control procedure without using the prior art ambient light sensors. Therefore, the portable electronic device of the present invention can be made smaller than the prior art portable electronic devices by getting rid of the prior art ambient light sensors. The practicability of the portable electronic device is thus increased.  
         [0027]     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.