Patent Publication Number: US-2006007223-A1

Title: Display control system and method

Description:
BACKGROUND  
      Electronic devices, such as portable telephones, notebook or laptop computers, projectors, personal digital assistants, desktop computers, televisions, and others, are generally configured to display an image using a variety of different methods (e.g., liquid crystal display (LCD), cathode-ray tube (CRT), etc.). Additionally, the environments in which such electronic devices are used greatly vary. For example, such electronic devices are generally capable of being used indoors and/or outdoors, thereby resulting in varied lighting conditions in which to use the electronic device. Further, lighting conditions may also change within a particular environment (e.g., lights dimmed or tuned off indoors; setting sun or cloudy conditions outdoors). Thus, maintaining image quality and visibility under varied lighting conditions is problematic for electronic devices.  
     SUMMARY OF THE INVENTION  
      In accordance with one embodiment of the present invention, a display control system comprises a display controller adapted to detect an ambient light condition about an electronic device. The display controller is also adapted to determine an optical response characteristic associated with the ambient light condition and automatically adjust a brightness of a display of the electronic device based on the optical response characteristic.  
      In accordance with another embodiment of the present invention, a display control system comprises a display controller adapted to detect an ambient light condition about an electronic device. The display controller is also adapted to determine an optical response characteristic associated with the ambient light condition and automatically adjust a color balance of an image displayed by the electronic device based on the optical response characteristic.  
      In accordance with another embodiment of the present invention, a display control system comprises a display controller adapted to detect a change in an ambient light condition about an electronic device. The display controller is also adapted to determine an optical response characteristic associated with the change in the ambient light condition and automatically adjust a rate of brightness change of a display of the electronic device based on the optical response characteristic. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following descriptions taken in connection with the accompanying drawings in which:  
       FIG. 1  is a diagram illustrating an embodiment of a display control system in accordance with the present invention;  
       FIG. 2  is a flow diagram illustrating an embodiment of a display control method in accordance with the present invention; and  
       FIG. 3  is a flow diagram illustrating another embodiment of a display control method in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
      The preferred embodiments of the present invention and the advantages thereof are best understood by referring to  FIGS. 1-3  of the drawings, like numerals being used for like and corresponding parts of the various drawings.  
       FIG. 1  is a diagram illustrating an embodiment of a display control system  10  in accordance with the present invention. Briefly, control system  10  controls and/or automatically adjusts a displayed image of an electronic device based on response characteristics of the human eye corresponding to ambient light conditions relative to the electronic device such as, but not limited to, the human eye&#39;s ability to adjust to changing light conditions (e.g., dark to light, and vice versa) and the human eye&#39;s ability to sense or perceive different colors under different lighting conditions.  
      In the embodiment illustrated in  FIG. 1 , system  10  comprises an electronic device  12  having a display device  14 . Electronic device  12  may comprise any type of device configured for displaying an image such as, but not limited to, a laptop or notebook computer, personal digital assistant, telephone, camera, desktop computer, television, or a projector. Accordingly, display device  14  may comprise any type of device for displaying an image such as, but not limited to, a liquid crystal display (LCD) or cathode-ray tube (CRT), or plasma display panel.  
      In the embodiment illustrated in  FIG. 1 , electronic device  12  comprises a display controller  20  for controlling various characteristics of an image displayed by electronic device  12 , such as via display device  14 . In the embodiment illustrated in  FIG. 1 , display controller  20  comprises a processor  22 , a memory  24 , color control logic  26 , and brightness control logic  28 . Color control logic  26  and brightness control logic  28  may comprise software, hardware, or a combination of software and hardware. In operation, display controller  20  uses color control logic  26  and/or brightness control logic  28  to control the display of an image by electronic device  12 , such as, but not limited to, color balance and brightness and/or contrast, based on ambient light conditions relative to electronic device  12  and based on optical response characteristics of the human eye. For example, in the embodiment illustrated in  FIG. 1 , electronic device  12  comprises a sensor  30  for detecting ambient light conditions relative to electronic device  12 . Thus, based on ambient light conditions about electronic device  12 , display controller  20  automatically adjusts display characteristics of a displayed image to accommodate optical response characteristics associated with the human eye.  
      In the embodiment illustrated in  FIG. 1 , memory  24  comprises ambient light condition data  40  and optical response characteristic data  50 . Ambient light condition data  40  comprises information associated with ambient light conditions relative to electronic device  12 , such as ambient light conditions detected by sensor  30 . In some embodiments of the present invention, ambient light condition data  40  comprises information associated with ambient light conditions relative to electronic device  12  occurring over a predetermined time period such that a comparison of ambient light condition data  40  values is performed by display controller  20  to detect or otherwise identify changes to ambient light conditions relative to electronic device  12 . Thus, in some embodiments of the present invention, display controller  20  dynamically controls a displayed image based on a human eye&#39;s response characteristics to changing light conditions.  
      Optical response characteristic data  50  comprises information associated with response characteristics of the human eye under different and/or changing light conditions. For example, different lighting conditions affect various functions of the human eye. For example, lighting conditions affect changes to the iris of the human eye such that the iris contracts or dilates to control the amount of light incident upon a retina of the human eye. The level of light also affects color perception or sensitivity of the human eye. Thus, in operation, optical response characteristic data  50  comprises information corresponding to human eye responsiveness related to various light conditions such that display controller  20  controls the display of an image based on human eye responsiveness to static and/or dynamic light conditions.  
      In the embodiment illustrated in  FIG. 1 , optical response characteristic data  50  comprises adaptive response time  60  and color balance sensitivity  62 . Adaptive response time  60  comprises information associated with time periods for the human eye to react or respond to changes in lighting conditions. For example, light conditions from dark to light, and vise versa, increases or decreases, respectively, the sensitivity of the retina of the human eye and generally requires a particular time period for the human eye to adapt to the change in light conditions. Color balance sensitivity  62  comprises information associated with the ability of the human eye to sense or perceive various colors at different light conditions. For example, the human eye comprises two types of photoreceptors (cones and rods) which operate differently under different lighting conditions such as, but not limited to, photopic conditions (when light is plentiful) and scotopic conditions (when light is scarce). Thus, under different lighting conditions, the human eye senses or perceives colors differently and/or lacks the ability to sense or perceive particular colors. Accordingly, in the embodiment illustrated in  FIG. 1 , in operation, display controller  20  uses adaptive response time  60  and color balance sensitivity  62  to control display characteristics of a displayed image such that brightness and color balance and/or color contrast of an image displayed by electronic device  12  is adjusted based on a human eye responsiveness to static and/or dynamic light conditions.  
      Thus, in operation, display controller  20  controls a brightness and/or contrast of a displayed image and/or color balance of a displayed image based on human eye characteristics as defined by optical response characteristic data  50 . For example, display controller  20  uses color control logic  26  to control a color balance of a displayed image of electronic device  12  based on optical response characteristic data  50  associated with ambient light conditions relative to electronic device  12  as detected by sensor  30 . Display controller  20  also uses brightness control logic  28  to control a brightness and/or contrast of a displayed image of electronic device  12  using optical response characteristic data  50  corresponding to ambient light conditions as detected by sensor  30 . In some embodiments of the present invention, display controller  20  dynamically controls the displayed image of electronic device  12  based on changes to ambient lighting conditions detected by sensor  30 . For example, display controller  20 , via color control logic  26  and/or brightness control logic  28 , accesses optical response characteristic data  50 , such as adaptive response time  60 , to determine response characteristics of the human eye corresponding to changing light conditions such that variations to the displayed image are made at a rate corresponding to a rate of human eye responsiveness. Thus, in operation, display controller  20  controls a rate of brightness change and/or color balance change corresponding to human eye responsiveness to changing light conditions as defined by optical response characteristic data  50 .  
      In operation, to control a color balance of a displayed image of electronic device  12 , display controller  20  uses color control logic  26  to detect or otherwise identify static and/or dynamic lighting conditions relative to electronic device  12  and identify an optical response characteristic of the human eye based on the detected static and/or dynamic lighting conditions via optical response characteristic data  50 . For example, in some embodiments of the present invention, display controller  20  uses control color logic  26  to access color balance sensitivity  62  indicating a perception or color sensitivity of the human eye in response to static and/or dynamic lighting conditions and adjusts the displayed image of electronic device  12  based on the optical response characteristic as defined by color balance sensitivity  62 . For example, in some embodiments of the present invention, display controller  20  is configured to adjust hue levels or values of the displayed image based on the human eye&#39;s ability to sense or perceive various colors under the detected light conditions as indicated by optical response characteristic data  50 . As described above, in response to dynamic light condition changes relative to electronic device  12 , display controller  20  uses color control logic  26  to control a rate of color balance change of the displayed image by accessing adaptive response time  60  and determining the optical response characteristic associated human eye reaction time to dynamic lighting condition changes to adjust a rate of color balance change to the displayed image. Thus, in some embodiments of the present invention, display controller  20  is adapted to perform color balance changes at a rate corresponding to the human eye&#39;s response or reaction time to ambient light changes.  
      In operation, to control a brightness and/or contrast of a displayed image, display controller  20  uses brightness control logic  28  to detect or otherwise identify static and/or dynamic lighting conditions relative to electronic device  12  and identify an optical response characteristic of the human eye based on the detected static and/or dynamic ambient light conditions via optical response characteristic data  50  to control a brightness and/or contrast of a displayed image. As described above, for dynamic light condition changes relative to electronic device  12 , display controller  20  uses brightness control logic  28  to access adaptive response time  60  to determine an optical response characteristic associated with time responsiveness of the human eye under dynamic light condition changes to control a rate of brightness and/or contrast change of the displayed image based on the dynamic ambient light conditions. Thus, in some embodiments of the present invention, display controller  20  is adapted to control a rate of brightness and/or contrast change of a display based on the human eye&#39;s response or reaction time to ambient light changes.  
       FIG. 2  is a flow diagram illustrating an embodiment of a display control method in accordance with the present invention. The method begins at block  100 , where display controller  20  detects or otherwise determines an ambient light condition relative to electronic device  12  via sensor  30 . At block  102 , display controller  20  accesses optical response characteristic data  50  to determine an optical response characteristic associated with the human eye based on the detected ambient light condition. At block  104 , display controller  20  adjusts a contrast and/or brightness of a displayed image of electronic device  12  based on the optical response characteristic corresponding to the detected ambient light condition. At block  106 , display controller  20  adjusts a color balance of the displayed image of electronic device  12  based on the optical response characteristic associated with the detected ambient light condition.  
       FIG. 3  is a flow diagram illustrating another embodiment of a display control method in accordance with the present invention. The method begins at block  200 , where display controller  20  monitors ambient light conditions relative to electronic device  12  via sensor  30 . At decisional block  202 , a determination is made whether an ambient light condition change is detected. If an ambient light condition change is not detected, the method proceeds to block  200 , where display controller  20  continues monitoring ambient light conditions. If an ambient light condition change is detected at block  202 , the method proceeds to decisional block  204 , where a determination is made whether a rate of the ambient light condition change exceeds a predetermined threshold. For example, in some embodiments of the present invention, display controller  20  is configured to adjust a rate of display characteristics change if a rate of ambient light condition change exceeds a predetermined threshold. If the rate of ambient light condition change does not exceed a predetermined threshold, the method proceeds to block  200 , where display controller  20  continues monitoring ambient light conditions relative to electronic device  12 . If a rate of ambient light condition change does exceed a predetermined threshold, the method proceeds to block  206 , where display controller  20  accesses optical response characteristic data  50 .  
      At block  208 , display controller  20  determines an optical response characteristic corresponding to the detected ambient light condition change. At block  210 , display controller  20  determines a display brightness for the display of electronic device  12  based on the optical response characteristic corresponding to the ambient light condition change. At block  212 , display controller  20  determines a color balance for the displayed image based on the optical response characteristic corresponding to the ambient light condition change.  
      At block  214 , display controller  20  determines an adaptive response time based on the optical response characteristic corresponding to the ambient light condition change. For example, as described above, display controller  20  accesses adaptive response time  60  to determine time responsiveness of the human eye in response to changing light conditions. At block  216 , display controller  20  adjusts the brightness of a displayed image of electronic device  12  at a rate corresponding to the optical response characteristic as indicated by adaptive response time  60 . At block  218 , display controller  20  adjusts a color balance of the displayed image at a rate corresponding to the optical response characteristic as indicated by adaptive response time  60 .  
      Thus, embodiments of the present invention enable automatic adjustment of a displayed image of an electronic device in response to static and/or dynamic light conditions based on human eye responsiveness to such light conditions. For example, embodiments of the present invention enable a brightness and/or contrast change to a displayed image to be mapped to human eye responsiveness to light conditions relative to the electronic device displaying the image. Additionally, embodiments of the present invention also enable a rate of brightness and/or contrast change to the displayed image to be controlled based on the human eye&#39;s rate of responsiveness or reaction to changing light conditions. Further embodiments of the present invention enable color adjustments or balancing of a displayed image based on the human eye&#39;s responsiveness to color at different light conditions. Embodiments of the present invention also enable a rate of color change to a displayed image to be controlled based on reaction time of the human eye to changes in light conditions. It should be understood that in the methods described in  FIGS. 2 and 3 , certain functions may be omitted, combined, or accomplished in a sequence different than depicted in  FIGS. 2 and 3 . Also, it should be understood that the methods depicted in  FIGS. 2 and 3  may be altered to encompass any of the other features or aspects described elsewhere in the specification.