Tiled electronic display structure and method for modular repair thereof

Abstract

A tiled display structure is formed containing a plurality of image tiles. A method for assembling a tiled display structure that includes a transparent front panel and a plurality of image tiles is disclosed. The method includes the steps of: (1) heating a heat activated adhesive to a working temperature; (2) applying the softened adhesive to the front surface of the display section of an image tile, or the inner surface of the transparent front panel; (3) aligning the surface of the display section of the image tile with the inner surface of the transparent front panel; (4) cooling the adhesive. Another aspect of the invention is a modular method of repairing a tiled display structure, which includes a transparent front panel, a heat activated adhesive, and a plurality of image tiles.

1. A tiled display structure comprising; :
 a plurality of image tiles;  
 a transparent front panel having an outer surface and an inner surface; and  
 a heat activated adhesive coupling the plurality of image tiles to the inner surface of the transparent front panel; and 
 whereina heating element configured to selectively soften the heat activated adhesive softens  with the application of heat at a softening temperature, and has a workingwherein the softening temperature which is greater than an operating temperature of the plurality of tiles andis less than a damage threshold temperature of the plurality of image tiles.  
 
     
     
       2. The tiled display structure of  claim 1 , wherein each image tile comprises; :
 a circuit board; and  
 a display section including a glass substrate having a front surface and a back surface including a plurality of pixel structures, each pixel structure defining a pixel area and having an active region which occupies a portion of the pixel area, the plurality of pixel structures being arranged in a matrix having rows and columns and including a plurality of contacts for receiving electrical signals.  
 
     
     
       3. The tiled display structure of  claim 2 , further comprising a black matrix mask having a plurality of rows and columns of dark-colored lines, the plurality of lines being substantially equal in width and defining a plurality of transparent regions oh  on the transparent front panel;
 wherein each of the plurality of transparent regions defined by the black matrix mask corresponds to an active region of a respective one of the plurality of pixel structures in the tiled display device.  
 
     
     
       4. The tiled display structure of  claim 3 , wherein the black matrix mask is coupled to the inner surface of the transparent front panel and the heat activated adhesive is disposed on the black matrix mask. 
     
     
       5. The tiled display structure of  claim 4 , wherein the plurality of lines in the black matrix mask contain resistive heating elements. 
     
     
       6. The tiled display structure of  claim 3 , wherein the black matrix mask is coupled to the outer surface of the transparent front panel. 
     
     
       7. The tiled display structure of  claim 3 , further comprising; :
 a plurality of row mullions extending horizontally between the plurality of image tiles; and  
 a plurality of column mullions extending vertically between the plurality of image tiles;  
 wherein the heat activated adhesive is disposed on the plurality of row mullions and the plurality of column mullions.  
 
     
     
       8. The tiled display structure of  claim 7 , wherein the plurality of row mullions and the plurality of column mullions include one of resistive heating elements and absorptive heating elements. 
     
     
       9. The tiled display structure of  claim 1 , wherein the working temperature of the heat activated adhesive is greater than 80° C. and less than 150° C. 
     
     
       10. The tiled display structure of  claim 1 , wherein the heat activated adhesive is a thermoplastic material. 
     
     
       11. The tiled display structure of  claim 10 , wherein the thermoplastic material contains at least one of polystyrene and acrylic. 
     
     
       12. The tiled display structure of  claim 2 , wherein the heat activated adhesive is transparent. 
     
     
       13. The tiled display structure of  claim 12 , wherein the heat activated adhesive is disposed substantially evenly over the front surface of the glass substrate. 
     
     
       14. The tiled display structure of  claim 2 , further comprising a plurality of heating elements coupled to the glass substrates of each of the respective plurality of image tiles. 
     
     
       15. The tiled display structure of  claim 2 , wherein; :
 the heat activated adhesive is formed on the inner surface of the transparent front panel as a plurality of rows and columns of dark-colored lines, the plurality of lines being substantially equal in width and defining a plurality of transparent regions; and  
 each of the plurality of transparent regions defined by the black matrix mask corresponds to the active region of a respective one of the pixel structures in a corresponding one of the image tiles.  
 
     
     
       16. A method of assembling a tiled display structure that includes a transparent front panel which has an inner surface and an outer surface, and a plurality of image tiles, each image tile including a display section which has a plurality of pixels in a matrix of rows and columns, the method comprising the steps of; :
 heating a heat activated adhesive to a working temperature above a softening point temperature and below a damage threshold temperature of the plurality of image tiles, wherein the tiled display structure comprises a heating element configured to selectively reheat the heat activated adhesive;  
 applying the heat activated adhesive to at least one of a surface of the display section of one of: a)  of the plurality of image tiles and b)  or the inner surface of the transparent front panel;  
 bringing the surface of the display section of the one of the plurality of image tiles into alignment with the inner surface of the transparent front panel such that the heat activated adhesive forms a thin layer between the surface of the display section or the one of the plurality of image tiles and the inner surface of the transparent front panel; and  
 cooling the heat activated adhesive to a temperature below the softening point temperature.  
 
     
     
       17. The method of  claim 16 , further comprising the step of coupling a black matrix mask containing a plurality of transparent regions to the transparent front panel using means which remain coupled at a temperature less than a bonding temperature which is greater than the working temperature. 
     
     
       18. The method of  claim 17 , wherein the step of bringing the surface of the display section of the one of the plurality of image tiles into alignment further comprises the step of arranging the one tile so that each pixel is centered on a respective one of the transparent regions of the black mask. 
     
     
       19. The method of  claim 16 , further comprising the step of coupling a plurality of row mullions and a plurality of column mullions to the inner surface of the transparent front panel using means which remain coupled at a temperature less than a bonding temperature which is greater than the working temperature, thereby defining a plurality of regions on the transparent front panel substantially corresponding with the plurality of image tiles in the tiled display device. 
     
     
       20. The method of  claim 19 , wherein the step of bringing the surface of the display section of the one of the plurality of image tiles into alignment further comprises the step of arranging the one tile  of the plurality of image tiles so that the one tile  of the plurality of image tiles is centered in one of the plurality of regions defined by the plurality of row mullions and the plurality of column mullions. 
     
     
       21. The method of  claim 16 , further comprising the step of placing the display section and the transparent front panel in a vacuum to prevent gas pockets from forming within the thin layer of heated, heat activated adhesive when the one of the plurality of image tile  tiles is brought into alignment with the surface of the display section. 
     
     
       22. The method of  claim 16 , wherein the heat activated adhesive is applied to the at least one surface  in a star pattern. 
     
     
       23. A method of repairing a tiled display structure that includes a transparent front panel which has an inner surface and an outer surface, a heat activated adhesive, and a plurality of image tiles including at least one defective tile, each image tile including a display section, the method comprising the steps of; :
 heating , using a heating element coupled to the transparent front panel, the heat activated adhesive to a working temperature above a softening point temperature and below a damage threshold temperature of the plurality of image tiles in a region of the tiled display structure corresponding to the at least one defective tile;  
 removing the at least one defective tile from the inner surface of the transparent front panel;  
 bringing a surface of a display section of a replacement image tile into alignment with a portion of the inner surface of the transparent front panel in the region corresponding to the at least one defective tile such that the heat activated adhesive forms a thin layer between the surface of the display section of the replacement image tile and the inner surface of the transparent front panel; and  
 cooling the heat activated adhesive to a temperature below the softening point temperature.  
 
     
     
       24. The method of  claim 23 , further comprising the step of applying further heat activated adhesive to at least one of a  the surface of a  the display section of a  the replacement image tile and a  the portion of the inner surface of the transparent front panel in the region of the at least one defective tile before bringing the surface of the display section of the replacement image tile into alignment with the portion of the inner surface of the transparent front panel. 
     
     
       25. The method of  claim 24 , further comprising the step of removing the heat activated adhesive from the region  portion of the inner surface of the transparent front panel corresponding to the at least one defective tile before applying the further heat activated adhesive. 
     
     
       26. The method of  claim 23 , wherein the step of heating the heat activated adhesive includes at least one of; :
 exposing the region of the tiled display structure to heated air from a heat gun;  
 illuminating the region of the tiled display structure with an optical heat source;  
 contacting the region of the tiled display structure with a resistive heating element;  
 exposing the region of the tiled display structure to a microwave source;  
 exposing the region of the tiled display structure to a flame; and  
 immersing the region of the tiled display structure in a hot liquid.  
 
     
     
       27. A display device comprising:
   a transparent panel comprising a first surface and a second surface;        a tiled display comprising at least one display tile coupled to at least one of the first surface or the second surface of the transparent panel with a heat activated adhesive; and        a heating element configured to soften the heat activated adhesive at a first temperature that is higher than an operating temperature of the tiled display.     
     
     
       28. The display device of  claim 27 , wherein a plurality of display tiles are coupled to the at least one of the first surface or the second surface of the transparent panel with a heat activated adhesive. 
     
     
       29. The display device of  claim 27 , wherein the at least one display tile comprises:
   a circuit board;        a display section including a front plate having a first surface and a second surface; and        a pixel structure formed on the second surface of the front plate, wherein the pixel structure defines a pixel area and has an active region that occupies a portion of the pixel area.     
     
     
       30. The display device of  claim 29 , wherein the at least one display tile comprises an insulating layer configured to insulate the circuit board from the display section. 
     
     
       31. The display device of  claim 29 , wherein the front plate comprises a glass substrate. 
     
     
       32. The display device of  claim 29 , wherein the heat activated adhesive is disposed substantially evenly over the first surface of the front plate. 
     
     
       33. The display device of  claim 29 , wherein the heating element is coupled to the front plate. 
     
     
       34. The display device of  claim 29 , wherein the pixel structure comprises a matrix of row electrodes and column electrodes, and wherein the pixel structure includes a contact capable of receiving an electrical signal. 
     
     
       35. The display device of  claim 29 , wherein the heat activated adhesive is disposed on the front surface of the transparent panel as one or more rows and columns of dark- colored lines, wherein the dark - colored lines define one or more transparent regions, and wherein the one or more transparent regions correspond to the active regions of respective pixel structures.   
     
     
       36. The display device of  claim 27 , further comprising:
   a matrix mask having rows and columns of lines, wherein the lines are substantially equal in width and define one or more transparent regions on the transparent panel;        wherein at least one of the one or more transparent regions corresponds to an active region of a pixel structure of the display tile.     
     
     
       37. The display device of  claim 36 , wherein the matrix mask is coupled to the first surface or the second surface of the transparent panel, and wherein the heat activated adhesive is disposed on the matrix mask. 
     
     
       38. The display device of  claim 36 , wherein the lines of the matrix mask include resistive heating elements. 
     
     
       39. The display device of  claim 27 , wherein the at least one display tile is attached to a second display tile via a mullion. 
     
     
       40. The display device of  claim 39 , wherein the heat activated adhesive is disposed on the mullion. 
     
     
       41. The display device of  claim 40 , wherein the mullion is coupled to the second display tile by the heat activated adhesive. 
     
     
       42. The display device of  claim 41 , wherein the mullion is coupled to the transparent panel by a second heat activated adhesive, wherein the second heat activated adhesive is configured to soften at a second temperature that is higher than the first temperature. 
     
     
       43. The display device of  claim 40 , further comprising a plurality of mullions arranged in one or more rows and in one or more columns extending between a plurality of display tiles. 
     
     
       44. The display device of  claim 40 , wherein the mullion includes at least one of a resistive heating element, an absorption heating element, or a thermocouple heating element. 
     
     
       45. The display device of  claim 27 , wherein the first temperature is greater than  80 ° C. and less than  150 ° C. 
     
     
       46. The display device of  claim 27 , wherein the heat activated adhesive comprises a thermoplastic material. 
     
     
       47. The display device of  claim 46 , wherein the thermoplastic material includes at least one of polystyrene or acrylic. 
     
     
       48. The display device of  claim 27 , wherein the heat activated adhesive is transparent. 
     
     
       49. The display device of  claim 27 , wherein the at least one display tile comprises a reflective display material. 
     
     
       50. The display device of  claim 27 , wherein the at least one display tile comprises a low power display material. 
     
     
       51. The display device of  claim 27 , wherein the at least one display tile comprises a bistable, reflective cholesteric ( BRC )  liquid crystal material.   
     
     
       52. A method of assembling a display device comprising:
   heating a heat activated adhesive to a working temperature, wherein the working temperature is higher than a softening temperature of the heat activated adhesive;        after said heating, applying the heat activated adhesive to a display tile or a surface of a transparent panel, wherein the display device comprises a heating element configured to selectively reheat the heat activated adhesive;        attaching the display tile to the surface of the transparent panel; and        cooling the heat activated adhesive to a temperature below the working temperature to harden the adhesive.     
     
     
       53. The method of  claim 52 , further comprising attaching a black matrix mask to the surface of the transparent panel using an adhesive that remains bonded at a temperature greater than the working temperature, wherein the black matrix mask defines a plurality of transparent regions. 
     
     
       54. The method of  claim 53 , further comprising aligning the display tile with the transparent panel so that the display tile is centered on a respective transparent region defined by the black matrix mask. 
     
     
       55. The method of  claim 52 , further comprising attaching a plurality of row mullions and column mullions to the transparent panel to define a plurality of regions for receiving the display tile. 
     
     
       56. The method of  claim 55 , further comprising aligning the display tile with a respective region of the plurality of regions for receiving the display tile. 
     
     
       57. The method of  claim 52 , further comprising attaching a back panel to the display tile and the transparent panel. 
     
     
       58. The method of  claim 57 , further comprising electrically connecting the back panel to the display tile. 
     
     
       59. The method of  claim 52 , further comprising placing the display tile and the transparent panel in a vacuum to prevent gas pockets from forming in the layer of heat activated adhesive. 
     
     
       60. The method of  claim 52 , wherein the step of applying the heat activated adhesive comprises applying the heat activated adhesive to the display tile or the surface of the transparent panel in a star pattern. 
     
     
       61. A method of repairing a display device comprising:
   selectively heating, using a heating element of the display device, a heat activated adhesive to a working temperature that is higher than a softening temperature of the heat activated adhesive, wherein the heat activated adhesive is in contact with a defective display tile that is coupled to a transparent panel;        removing the defective display tile from the transparent panel;        attaching a replacement display tile to the transparent panel in a region formerly occupied by the defective display tile, wherein the heat activated adhesive is configured to form a layer between the replacement display tile and the transparent panel; and        cooling the heat activated adhesive to a temperature below the softening temperature to secure the replacement display tile to the transparent panel.     
     
     
       62. The method of  claim 61 , further comprising:
   loosening a neighboring display tile of the defective display tile by heating a second heat activated adhesive corresponding to the neighboring display tile;        replacing the neighboring display tile; and        cooling the second heat activated adhesive to a second temperature below the softening temperature to secure a replacement neighboring display tile to the transparent panel.     
     
     
       63. The method of  claim 61 , further comprising applying additional heat activated adhesive to the replacement display tile or the transparent panel in the region formerly occupied by the defective display tile. 
     
     
       64. The method of  claim 63 , further comprising removing the heat activated adhesive from the transparent panel in the region formerly occupied by the defective display tile prior to applying the additional heat activated adhesive. 
     
     
       65. The method of  claim 61 , further comprising:
   applying additional heat activated adhesive to a mullion defining at least a portion of the region formerly occupied by the defective display tile; and        aligning the replacement display tile with the region formerly occupied by the defective display tile according to the mullion.     
     
     
       66. The method of  claim 61 , further comprising aligning the replacement display tile with the region formerly occupied by the defective display tile, wherein at least a portion of the region is defined by a black matrix mask. 
     
     
       67. The method of  claim 61 , wherein the step of heating the heat activated adhesive further comprises exposing the region formerly occupied by the defective display tile to heated air from a heat gun. 
     
     
       68. The method of  claim 61 , wherein the step of heating the heat activated adhesive further comprises illuminating the region formerly occupied by the defective display tile with an optical heat source. 
     
     
       69. The method of  claim 61 , wherein the step of heating the heat activated adhesive further comprises contacting the region formerly occupied by the defective display tile with a resistive heating element. 
     
     
       70. The method of  claim 61 , wherein the step of heating the heat activated adhesive further comprises exposing the region formerly occupied by the defective display tile to a microwave source. 
     
     
       71. The method of  claim 61 , wherein the step of heating the heat activated adhesive further comprises exposing the region formerly occupied by the defective display tile to a flame. 
     
     
       72. The method of  claim 61 , wherein the step of heating the heat activated adhesive further comprises immersing the region formerly occupied by the defective display tile in a hot liquid.