Wide viewing angle liquid crystal display comprising at least one floating electrode in locations facing corresponding one or more pixel electrodes with liquid crystal layer therebetween

Abstract

A liquid crystal display (LCD) device. In one embodiment, the LCD device includes a first substrate and a second substrate positioned apart from the first substrate, a liquid crystal layer positioned between the first substrate and the second substrate, and a plurality of pixels. Each pixel includes two or more first common electrodes and one or more pixel electrodes formed on the first substrate, where each of the one or more pixel electrodes is located between two of the two or more first common electrodes. Each pixel further includes one or more floating electrodes and/or two or more second electrodes formed on the second substrate in locations opposite corresponding ones of the one or more pixel electrodes and the two or more first common electrodes on the first substrate.

What is claimed is: 
     
       1. A liquid crystal display (LCD) device, comprising:
 a. a first structure comprising:
 i. a first substrate having a first surface and an opposite, second surface defining a body portion therebetween; 
 ii. a plurality of scanning lines regularly spaced and formed on the second surface of the first substrate along a first direction; 
 iii. an insulation layer formed on the first substrate covering the plurality of scanning lines; 
 iv. a plurality of signal lines regularly spaced and formed on the insulation layer crossing over the plurality of scanning lines along a second direction that is substantially perpendicular to the first direction; 
 v. a passivation layer formed on the insulation layer covering the plurality of signal lines thereon; 
 vi. a plurality of first common electrodes regularly spaced and formed on the passivation layer along the second direction; and 
 vii. a plurality of pixel electrodes regularly spaced and formed on the passivation layer along the second direction, each of the pixel electrodes located between two neighboring first common electrodes; 
 
 b. a second structure comprising:
 i. a second substrate having a first surface and an opposite, second surface defining a body portion therebetween; 
 ii. a black matrix formed on the first surface of the second substrate directly facing the plurality of scanning lines and the plurality of signal lines in the first structure; 
 iii. a color filter layer formed on the remaining portion of the second substrate; 
 iv. an overcoat layer formed on the color filter layer and the black matrix; 
 v. a plurality of second common electrodes regularly spaced and formed on the overcoat layer along the second direction, each of the plurality of second common electrodes directly facing a corresponding one of the plurality of first common electrodes on the first substrate; and 
 vi. a plurality of floating electrodes regularly spaced and formed on the overcoat layer on the second substrate along the second direction, each of the plurality of floating electrodes directly facing a corresponding one of the plurality of pixel electrodes on the first substrate; 
 wherein the first structure and the second structure are positioned relative to each other such that a cell gap is defined therebetween; and 
 
 c. a liquid crystal layer having a plurality of liquid crystal molecules, the liquid crystal layer being positioned in the cell gap between the first structure and the second structure;
 wherein each of the plurality of floating electrodes is electrically disconnected from floating and is not directly electrically connected to the pixel electrodes, the first common electrodes, and the second common electrodes, such that, when a signal voltage is applied to a pixel electrode, the voltage is coupled to a corresponding floating electrode via the capacitance between the pixel electrode and the floating electrode, thereby inducing an electric field in the liquid crystal layer in the region between the pixel electrode, the floating electrode, the first common electrodes and the second common electrodes, and wherein the liquid crystal molecules in the region are rotated according to the electric field. 
 
 
     
     
       2. The LCD device of  claim 1 , wherein the liquid crystal layer comprises nematic liquid crystals having a positive dielectric anisotropy. 
     
     
       3. The LCD device of  claim 2 , wherein the liquid crystals are selected such that a product of the refractive index δ n  of the liquid crystals and the cell gap is in a range of about 0.15-0.60 μm. 
     
     
       4. The LCD device of  claim 1 , wherein each of the pixels electrode and one of its two neighboring first common electrodes define a distance therebetween, which is greater than the cell gap. 
     
     
       5. The LCD device of  claim 1 , wherein the first structure further comprises a first alignment layer formed on the passivation layer covering the plurality of pixel electrodes and the plurality of first common electrodes thereon, and wherein the second structure further comprises a second alignment layer formed on the overcoat layer covering the plurality of floating electrodes and the plurality of second common electrodes thereon. 
     
     
       6. The LCD device of  claim 5 , wherein each of the first alignment layer and the second alignment layer is formed to have a rubbing axis with a pre-tilted angle in a range of about 0-10 degrees relative to the second direction so as to align the liquid crystals to a desired direction. 
     
     
       7. The LCD device of  claim 6 , further comprising:
 a. a polarizer formed on the first surface of the first substrate, the polarizer having a polarizing axis in a first predetermined direction, the polarizing axis being optically related to the liquid crystal layer; and 
 b. an analyzer formed on the second surface of the second substrate, the analyzer having an absorbing axis in a second predetermined direction, the absorbing axis being optically related to the polarizer. 
 
     
     
       8. The LCD device of  claim 7 , wherein the polarizing axis of the polarizer and the rubbing axis of the first alignment layer define an angle in a range of about 0-90 degrees, and wherein the polarizing axis of the polarizer is about 90 degrees relative to the absorbing axis of the analyzer. 
     
     
       9. The LCD device of  claim 1 , wherein each of the plurality of first common electrodes is located over a corresponding one of the plurality of signal lines. 
     
     
       10. The LCD device of  claim 1 , wherein each pair of the plurality of first common electrodes is distantly located over a corresponding one of the plurality of signal lines. 
     
     
       11. The LCD device of  claim 1 , wherein each of the plurality of pixel electrodes, the plurality of floating electrodes, the plurality of first common electrodes and the plurality of second common electrodes is formed of a transparent, conductive material including indium zinc oxide (IZO), amorphous indium tin oxide (ITO), poly ITO, or any combination of them, with a thickness in the range of about 0.01-3.0 μm. 
     
     
       12. A liquid crystal display (LCD) device, comprising:
 a. a first substrate and a second substrate positioned apart to define a cell gap therebetween; 
 b. a liquid crystal layer having a plurality of liquid crystal molecules, the liquid crystal layer being positioned in the cell gap between the first substrate and the second substrate; 
 c. a plurality of scanning lines formed on the first substrate along a first direction and a plurality of signal lines formed on the first substrate crossing over the plurality of scanning lines along a second direction that is perpendicular to the first direction; and 
 d. a plurality of pixels, each of the pixels being defined between two neighboring scanning lines and two neighboring signal lines crossing over the two neighboring scanning lines and comprising:
 i. an insulation layer formed on the first substrate; 
 ii. two or more first common electrodes formed on the insulation layer along the second direction, two of the two or more first common electrodes located over the two neighboring signal lines, respectively; 
 iii. one or more pixel electrodes formed on the insulation layer between the two of the two or more first common electrodes along the second direction; 
 iv. a black matrix formed on the second substrate in locations directly facing the two neighboring scanning lines and the two neighboring signal lines crossing over the two neighboring scanning lines in the first substrate; 
 v. a color filter layer formed on the second substrate in an area surrounded by the black matrix; 
 vi. an overcoat layer formed on the black matrix and the color filter; 
 vii. two or more second common electrodes formed on the overcoat layer along the second direction, the two or more second common electrodes directly facing corresponding two or more first common electrodes on the first substrate; and 
 viii. at least one of one or more floating electrodes formed on the overcoat layer on the second substrate along the second direction in locations directly facing corresponding ones of the one or more pixel electrodes formed on the first substrate; 
 wherein the at least one of one or more floating electrodes is electrically disconnected from floating and is not directly electrically connected to the pixel electrodes, the first common electrodes, and the second common electrodes, such that, when a signal voltage is applied to a pixel electrode, the voltage is coupled to a corresponding floating electrode via the capacitance between the pixel electrode and the floating electrode, thereby inducing an electric field in the liquid crystal layer in the region between the pixel electrode, the floating electrode, the first common electrodes and the second common electrodes, and wherein the liquid crystal molecules in the region are rotated according to the electric field. 
 
 
     
     
       13. The LCD device of  claim 12 , wherein the liquid crystal layer comprises nematic liquid crystals having a positive dielectric anisotropy. 
     
     
       14. The LCD device of  claim 13 , wherein the liquid crystals are selected such that a product of the refractive index δ n  of the liquid crystals and the cell gap is in a range of about 0.15-0.60 μm. 
     
     
       15. The LCD device of  claim 12 , wherein each of the pixels further comprises a switch device electrically coupled with the one or more pixel electrodes. 
     
     
       16. The LCD device of  claim 12 , wherein each of the pixels further comprises:
 a. a first alignment layer formed on the passivation layer covering the plurality of pixel electrodes and the plurality of first common electrodes thereon; and 
 b. a second alignment layer formed on the overcoat layer covering the plurality of floating electrodes and the plurality of second common electrodes thereon. 
 
     
     
       17. The LCD device of  claim 16 , wherein each of the first alignment layer and the second alignment layer is formed to have a rubbing axis with a pre-tilted angle in a range of about 0-10 degrees relative to the second direction so as to align the liquid crystals to a desired direction. 
     
     
       18. The LCD device of  claim 17 , further comprising:
 a. a polarizer formed on an exterior surface of the first substrate, the polarizer having a polarizing axis in a first predetermined direction, the polarizing axis being optically related to the liquid crystal layer; and 
 b. an analyzer formed on an exterior of the second substrate, the analyzer having an absorbing axis in a second predetermined direction, the absorbing axis being optically related to the polarizer. 
 
     
     
       19. The LCD device of  claim 18 , wherein the polarizing axis of the polarizer and the rubbing axis of the first alignment layer define an angle in a range of about 0-90 degrees, and wherein the polarizing axis of the polarizer is about 90 degrees relative to the absorbing axis of the analyzer. 
     
     
       20. A liquid crystal display (LCD) device, comprising:
 a. a first substrate and a second substrate positioned apart from the first substrate; 
 b. a liquid crystal layer having a plurality of liquid crystal molecules, the liquid crystal layer being positioned between the first substrate and the second substrate; and 
 c. a plurality of pixels, each of the pixels comprising:
 i. two or more first common electrodes formed on the first substrate; 
 ii. one or more pixel electrodes formed on the first substrate, each of the one or more pixel electrodes located between two of the two or more first common electrodes; 
 iii. two or more second common electrodes formed on the second substrate in locations directly facing corresponding ones of the two or more first common electrodes on the first substrate; and 
 iv. at least one of one or more floating electrodes formed on the second substrate in locations directly facing corresponding ones of the one or more pixel electrodes on the first substrate; 
 wherein the at least one of one or more floating electrodes is electrically disconnected from floating and is not directly electrically connected to the pixel electrodes, the first common electrodes, and the second common electrodes, such that, when a signal voltage is applied to a pixel electrode, the voltage is coupled to a corresponding floating electrode via the capacitance between the pixel electrode and the floating electrode, thereby inducing an electric field in the liquid crystal layer in the region between the pixel electrode, the floating electrode, the first common electrodes and the second common electrodes, and wherein the liquid crystal molecules in the region are rotated according to the electric field. 
 
 
     
     
       21. The LCD device of  claim 20 , wherein the liquid crystal layer comprises nematic liquid crystals having a positive dielectric anisotropy. 
     
     
       22. The LCD device of  claim 20 , wherein each of the pixels further comprises a switch device electrically coupled with the one or more pixel electrodes. 
     
     
       23. The LCD device of  claim 20 , wherein each of the pixels further comprises:
 a. a first alignment layer formed on the plurality of pixel electrodes and the plurality of first common electrodes thereon; and 
 b. a second alignment layer formed on the plurality of floating electrodes and the plurality of second common electrodes thereon. 
 
     
     
       24. The LCD device of  claim 23 , wherein each of the first alignment layer and the second alignment layer is formed to have a rubbing axis with a pre-tilted angle in a range of about 0-10 degrees relative to the direction of the one or more pixel electrodes so as to align the liquid crystals to a desired direction. 
     
     
       25. A liquid crystal display (LCD) device, comprising:
 a. a first substrate and a second substrate positioned apart from the first substrate; 
 b. a liquid crystal layer positioned between the first substrate and the second substrate, the liquid crystal layer having a plurality of liquid crystal molecules; and 
 c. a plurality of pixels, each of the pixels comprising:
 i. two or more first common electrodes formed on the first substrate; 
 ii. one or more pixel electrodes formed on the first substrate, each of the one or more pixel electrodes located between two of the two or more first common electrodes; 
 iii. two or more second common electrodes formed on the second substrate in locations directly facing corresponding ones of the two or more first common electrodes on the first substrate; and 
 iv. at least one floating electrode formed on the second substrate in locations directly facing a corresponding one of the one or more pixel electrodes on the first substrate; 
 wherein the at least one floating electrode is electrically disconnected from floating and is not directly electrically connected to the pixel electrodes, the first common electrodes, and the second common electrodes, such that, when a signal voltage is applied to a pixel electrode, the voltage is coupled to a corresponding floating electrode via the capacitance between the pixel electrode and the floating electrode, thereby inducing an electric field in the liquid crystal layer in the region between the pixel electrode, the floating electrode, the first common electrodes and the second common electrodes, and wherein the liquid crystal molecules in the region are rotated according to the electric field.