Light-emitting diode display

Abstract

The present invention relates to a light-emitting diode (“LED”) display apparatus used for a display such as a type of standing signboard. The light-emitting diode display is comprised of light-emitting diodes which use a plurality of colors, including blues, reds and greens, arranged in a specific pattern such as a matrix pattern. The display is appropriate for displaying either a moving or a stationary graphical image by powering the LEDs to combine to produce specific colors.

1. A method for displaying an image on a light-emitting diode display, the display having a first set of light-emitting diodes capable of emitting light having a first set of at least four chromaticities, method comprising:
 identifying at least a first light-emitting diode from said first set capable of emitting light having at least one chromaticity for which an operating parameter is to be minimized;  
 identifying a first region of chromaticity with a boundary available through operation of said at least one light-emitting diode and a first subset of said first set of light emitting diodes capable of emitting light having a first subset of chromaticities;  
 identifying a second region of chromaticity with a second boundary available through operation of a second subset of light emitting diodes capable of emitting light having a second subset of chromaticities;  
 specifying a desired color;  
 determining whether the desired color resides within the second boundary;  
 generating the desired color using the second set of light-emitting diodes if the desired color resides within the second boundary, thereby minimizing said operating parameter; and  
 generating the desired color using said at least one light-emitting diode and the second set of light-emitting diodes if the desired color does not reside within the second boundary.  
 
     
     
       2. The method of  claim 1 , wherein the operating parameter to be minimized is power. 
     
     
       3. The method of  claim 1 , wherein the operating parameter to be minimized is current. 
     
     
       4. The method of  claim 1 , wherein the operating parameter to be minimized is operating time. 
     
     
       5. The method of  claim 1 , further comprising the step of verifying that the desired color resides within the first boundary. 
     
     
       6. The method of  claim 1 , further comprising the step of verifying that the desired color resides within the first boundary or the second boundary. 
     
     
       7. A light-emitting diode display comprising:
 a plurality of pixels arranged in a plurality of rows and columns to display a predetermined image, the plurality of pixels composed of a first set of light-emitting diodes capable of emitting light having a first set of at least four chromaticities;  
 digital input circuitry to input a digital signal for a desired color and a desired luminance;  
 a digital-to-analog converter capable of converting the digital signal to an analog signal, the digital-to-analog converter having a dynamic range;  
 control electronics capable of driving the plurality of pixels; and  
 a threshold operator capable of determining whether the desired color is within a first region of chromaticity with a first boundary available through operation of at least one light-emitting diode capable of emitting light having a first chromaticity and a first subset of said first set of light emitting diodes capable of emitting light having a first subset of chromaticities, wherein the first subset of light emitting diodes is less than or equal in number to the first set;  
 the threshold operator further capable of determining whether the desired color is within a second region of chromaticity with a second boundary available through operation of second subset of the first set of light emitting diodes having a second subset of chromaticities, the second subset not including the first light-emitting diode and, wherein the second subset of light-emitting diodes is less than or equal to the first set.  
 
     
     
       8. The light-emitting diode display of  claim 7 , wherein the desired color is within the first region of chromacity and the control electronics drives the at least one light-emitting diode and the second set of light-emitting diodes to generate the desired color. 
     
     
       9. The light-emitting diode display of  claim 7 , wherein the desired color is within the second region of chromacity and the control electronics drives the third set of light-emitting diodes to generate the desired color. 
     
     
       10. The light-emitting diode display of  claim 7 , wherein the control electronics implements a non-linear control function. 
     
     
       11. The light-emitting diode display of  claim 9 , wherein the control electronics implements a polynomial function. 
     
     
       12. The light-emitting diode display of  claim 9 , wherein the control electronics implements a piece-wise linear function. 
     
     
       13. The light-emitting diode display of  claim 9 , wherein the control electronics implements a control function closely matching human perceptible just-noticeable difference in intensity. 
     
     
       14. The light-emitting diode display of  claim 7 , wherein the parameter is power. 
     
     
       15. The light-emitting diode display of  claim 7 , wherein the parameter is current. 
     
     
       16. The light-emitting diode display of  claim 7 , wherein the parameter is operating time. 
     
     
       17. A light-emitting diode display system comprising:
 a first set of light-emitting diodes capable of emitting light having a first set of chromacities, the first set of chromacities being equal to or greater than four;  
 a first memory device for storing digital information;  
 a first computer processor capable of executing the steps of 
 identifying at least one light-emitting diode capable of emitting light having a at least one chromacity from within the first set of diodes for which a parameter is to be minimized;  
 identifying a first region of chromacity with a first boundary available through operation of the at least one light-emitting diode and a second set of light emitting diodes capable of emitting light having a second set of chromacities, wherein the second set of light emitting diodes is less than or equal to the first set;  
 
 identifying a second region of chromacity with a second boundary available through operation of a third set of light emitting diodes capable of emitting light having a third set of chromacities, the third set not including the first light-emitting diode and, wherein the third set of light-emitting diodes is less than or equal to the first set;  
 specifying a desired color;  
 determining whether the desired color resides within the second boundary;  
 if the desired color resides within the second boundary, generating the desired color using the third set of light-emitting diodes; and  
 if the desired color does not reside within the second boundary, generating the desired color using the at least one light-emitting diode and the second set of light-emitting diodes.  
 
     
     
       18. The system of  claim 17 , wherein the parameter to be minimized is power. 
     
     
       19. The system of  claim 17 , wherein the parameter to be minimized is current. 
     
     
       20. The system of  claim 17 , wherein the parameter to be minimized is operating time. 
     
     
       21. The system of  claim 17 , wherein the first computer processor is further capable of executing the step of verifying that the desired color resides within the first boundary. 
     
     
       22. The system of  claim 17 , wherein the first computer processor is further capable of executing the step of verifying that the desired color resides within the first boundary or the second boundary. 
     
     
       23. The system of  claim 17 , wherein a second computer processor is capable of sharing the executing the steps of
 identifying at least one light-emitting diode capable of emitting light having a at least one chromacity from within the first set of diodes for which a parameter is to be minimized;  
 identifying a first region of chromacity with a first boundary available through operation of the at least one light-emitting diode and a second set of light emitting diodes capable of emitting light having a second set of chromacities, wherein the second set of light emitting diodes is less than or equal to the first set;  
 identifying a second region of chromacity with a second boundary available through operation of a third set of light emitting diodes capable of emitting light having a third set of chromacities, the third set not including the first light-emitting diode and, wherein the third set of light-emitting diodes is less than or equal to the first set;  
 specifying a desired color;  
 determining whether the desired color resides within the second boundary;  
 if the desired color resides within the second boundary, generating the desired color using the third set of light-emitting diodes; and  
 if the desired color does not reside within the second boundary, generating the desired color using the at least one light-emitting diode and the second set of light-emitting diodes.  
 
     
     
       24. An electronic billboard system comprising:
   an electronic display;        a communication interface to a wide area network;        a feedback control system having one or more sensors sensitive to the image displayed on the electronic display and the environment to provide output signals indicative of a quality parameter of pixels in the electronic display; and        a controller for  (   1   )  controlling displaying an image of the electronic display;  (   2   )  communicating over the communication interface to receive the image for display on the electronic display; and  (   3   )  adjusting the image on the electronic display by varying the intensity of individual colors of the pixels in accordance with a prescribed intensity scale for each color and the output signals from the feedback control system.      
     
     
       25. An electronic billboard system as in  claim 24 , wherein the electronic display comprises a light- emitting diode display.    
     
     
       26. An electronic billboard system as in  claim 24 , wherein the quality parameter of the electronic display comprises brightness.  
     
     
       27. An electronic billboard system as in  claim 26 , wherein the brightness spans a dynamic range between  1 : 1  to  2000 : 1 .  
     
     
       28. An electronic billboard system as in  claim 27 , wherein the feedback control system comprises a camera.  
     
     
       29. An electronic billboard system as in  claim 24 , wherein the feedback control system detects the light pattern of the electronic display.  
     
     
       30. An electronic billboard system as in  claim 28 , wherein the output signals represent a digital representation of a distribution of the brightness.  
     
     
       31. An electronic billboard system as in  claim 24 , wherein the sensors detect a color pattern of the electronic display.  
     
     
       32. An electronic billboard system as in  claim 31 , wherein the output signals represent a digital representation of a distribution of the colors on the electronic display.  
     
     
       33. An electronic billboard system as in  claim 24 , wherein the output signals are provided over the wide area network to a remote computer.  
     
     
       34. An electronic billboard system as in  claim 33 , wherein the controller further adjusts the electronic display in accordance with control signals received over the wide area network from a remote computer.  
     
     
       35. An electronic billboard system as in  claim 34 , wherein the controller further receives multiple images from the remote workstation and an image display sequence for displaying the multiple images.  
     
     
       36. An electronic billboard system as in  claim 34 , wherein the controller reports a status of the electronic billboard system to the remote computer.  
     
     
       37. An electronic billboard system as in  claim 24 , wherein the communication interface provides a virtual private network service for communication over the wide area network.  
     
     
       38. An electronic billboard system as in  claim 24 , wherein the communication interface provides encryption and decryption services for communication over the wide area network.  
     
     
       39. An electronic billboard system as in  claim 24 , wherein the electronic display comprises an array of pixels.  
     
     
       40. An electronic billboard system as in  claim 39 , wherein each pixel comprises a plurality of light sources of different colors.  
     
     
       41. An electronic billboard system as in  claim 40 , wherein each pixel comprises light sources of four or more different colors.  
     
     
       42. An electronic billboard system as in  claim 41 , wherein the different colors comprise two or more shades of green. 
     
     
       43. A method for displaying an image on a light- emitting diode  ( LED )  display, the display comprising a matrix of pixels, each pixel made up of at least four LEDs each capable of emitting light, at an individual chromaticity, the method comprising:      specifying a color to be displayed at a pixel;        selecting a color gamut from a plurality of color gamuts, each color gamut being defined by three or more of said LEDs, according to the specified color and an operating characteristic; and        generating said specified color using said selected color gamut.      
     
     
       44. The method of  claim 43 , wherein one of said plurality of color gamuts is defined by at least four LEDs.  
     
     
       45. The method according to  claim 43 , wherein said selecting comprises:
   selecting a specific LED within a pixel for which an operating parameter is to be optimized; and        selecting the color gamut most closely associated with said optimized operating parameter.      
     
     
       46. The method according to  claim 43 , wherein said operating characteristic is selected from the group consisting of power consumption, current draw, time usage and brilliance.  
     
     
       47. The method according to  claim 43 , wherein generating said specified color includes driving the selected gamut using a non- linear control circuit.    
     
     
       48. The method according to  claim 47 , wherein the non- linear control circuit has a characteristic function approximating human just-noticeable differences in luminance.    
     
     
       49. The method according to  claim 47 , wherein the non- linear control circuit has a polynomial characteristic function approximating human just - noticeable differences in luminance.    
     
     
       50. The method according to  claim 47 , wherein the non- linear control circuit has a exponential characteristic function approximating human just - noticeable differences in luminance.    
     
     
       51. The method according to  claim 47 , wherein the non- linear control circuit has a piece - wise linear characteristic function approximating human just - noticeable differences in luminance.    
     
     
       52. The method according to  claim 43 , wherein generating said specified color includes dividing a range of luminance into a set of increments.  
     
     
       53. The method according to  claim 52 , wherein the set of increments are spaced to approximate human just- noticeable differences in luminance.    
     
     
       54. The method according to  claim 52 , wherein the set of increments are spaced according to a polynomial function approximating human just- noticeable differences in luminance.    
     
     
       55. The method according to  claim 52 , wherein the set of increments are spaced according to an exponential function approximating human just- noticeable differences in luminance.    
     
     
       56. The method according to  claim 52 , wherein the set of increments are spaced according to a piece- wise linear function approximating human just - noticeable differences in luminance.    
     
     
       57. The method according to  claim 53  further comprising:
   detecting an output of the LED display; and        adjusting a range of luminance for the output of the LED display.      
     
     
       58. A light- emitting diode  ( LED )  display system, comprising:      a matrix of pixels each having a plurality of LEDs, each pixel emitting light of four or more different chromaticities forming a color gamut associated with an operating parameter; and        a processor controlling the matrix of pixels, the processor  ( a )  receiving information specifying each color to be displayed on the LED display system and specifying an operating characteristic for that pixel, and  ( b )  selecting the color gamut for each pixel by matching the operating parameter of the gamut to the specified operating characteristic.      
     
     
       59. The LED display system according to  claim 58 , wherein the matrix of pixels is shaded using a plurality of louvers.  
     
     
       60. The LED display system according to  claim 58 , wherein the matrix of pixels comprises an array of pixel blocks.  
     
     
       61. The LED display system according to  claim 58 , wherein the processor receives feedback from a camera detecting an output of the LED display system.  
     
     
       62. The LED display system according to  claim 61 , wherein the processor specifies the luminance or chrominance for each pixel in the matrix of pixels in response to the output of the LED display system.  
     
     
       63. The LED display system according to  claim 62 , wherein the luminance or chrominance spans a range that is divided into increments with spacing corresponding to human just- noticeable differences.    
     
     
       64. The LED display system according to  claim 62 , wherein the luminance or chrominance spans a range that is divided into increments with spacing corresponding to a polynomial function approximating human just- noticeable differences.    
     
     
       65. The LED display system according to  claim 62 , wherein the luminance or chrominance spans a range that is divided into increments with spacing corresponding to an exponential function approximating human just- noticeable differences.    
     
     
       66. The LED display system of  claim 62 , wherein the luminance spans a range that is divided into increments with spacing corresponding to a piece- wise linear function approximating human just - noticeable differences.