Patent Publication Number: US-2003231274-A1

Title: MVA pixel for liquid crystal display

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention relates in general to a multi-domain vertical alignment (MVA) pixel for liquid crystal display (LCD). In particular, the present invention relates to pixels for a high resolution, multi-domain vertical alignment (MVA), liquid crystal display.  
       [0003] 2. Description of the Related Art  
       [0004] Liquid Crystal Displays (LCDs) are widely utilized in the personal computers, digital camera and projectors because of its low power consumption, thin profile, light weight, and low driving voltage.  
       [0005] However, LCDs present several disadvantages and limitations, among narrow view angle. At present, a number of propositions for manufacturing wide view angle LCD are in the developing stage. The most widely adopted technique is the so-called multi-domain vertical alignment (MVA) technology. The alternately positioned slit-spacing-protrusion structure in each pixel is used and a single pixel is divided into several domains so that liquid crystal molecules in different domains have different tilt directions. Hence, view angle of the LCD is increased.  
       [0006]FIG. 1 shows a top view of the traditional MVA pixel. In the figure, reference numeral  10  indicates a storage capacitor, reference numeral  20  indicates bumps, and reference numeral  30  indicates slits. FIG. 2 is a cross-section taken along A-A′ cut line of FIG. 1. In the figure, reference numeral  40  indicates transparent electrodes formed of, for example, ITO or SnO, reference numeral  50  indicates an upper panel, reference numeral  60  indicates a lower panel, and reference numeral  80  indicates liquid crystal molecules. Because the slits  30  and the bumps  20  are alternately arranged and inclined in each MVA pixel, electric field directions are different in some regions when a voltage is applied across the pixel area. In other words, the regions I totally controlled by the tilted slits  30  and tilted bumps  20  have better light transmittance, as shown in FIG. 1, which are called bright regions. The peripheral regions II of the pixel are dull regions, because the electric field is different from the desired electric field. The brightness of the dull regions II is about 65% of the bright regions I.  
       [0007] As can be seen in FIG. 1, the total transmittance of the traditional MVA pixel is not high enough, and its effective aperture ratio is only about 30% in 200 dpi. It is known that if MVA technology is adapted to high resolution LCDs (150 dpi-200 dpi over), the bright regions I may shrink with improvement of resolution, and the LCDs cannot be used due to its bad transmittance efficiency. Therefore, increasing the area of the bright regions and reducing the area of the dull regions in each MVA pixel is important for high resolution LCDs.  
       SUMMARY OF THE INVENTION  
       [0008] An object of the present invention is thus to provide a MVA pixel for a liquid crystal display comprising a liquid crystal layer between a first glass panel and a second glass panel. The MVA pixel comprises a protrusion element formed on an inner surface of the first glass panel and a conducting layer with a first slit and a second slit formed on an inner surface of the second glass panel, wherein the protrusion element is disposed facing the first slit.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0009] The present invention will become more fully understood from the detailed description given herein and the accompanying drawings, given by way of illustration only and thus not intended to be limitative of the present invention.  
     [0010]FIG. 1 shows a top view of a traditional MVA pixel.  
     [0011]FIG. 2 shows a cross-section taken along A-A′ cut line of FIG. 1.  
     [0012]FIG. 3 shows a top view of a MVA pixel according to an embodiment of the present invention.  
     [0013]FIG. 4 shows a cross-section taken along B-B′ cut line of FIG. 3.  
     [0014]FIG. 5 shows a top view of arranged MVA pixels according to an embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0015]FIG. 3 shows a top view of a MVA pixel according to the embodctive view of still another embodiment of a flow controller according to the present invention, included in a different exemplary valve assembly.  
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0016] First Embodiment of Flow Controller  
     [0017] FIGS.  2 - 5  illustrate a first embodiment of a flow controller  20  that adjusts the flow of compressed gas through a recock gas passageway  22 , in accord with the present invention. As shown therein, the flow controller and recock gas passageway are disposed within a valve assembly  24  that is included in an exemplary pneumatic gun  28 . Valve assembly  24  is normally closed and opens as a result of an impact by a spring driven component when the gun is fired. Pneumatic gun  28  is configured for propelling paintballs, but can readily be alternatively configured for propelling other types of projectiles, such as BBs or pellets.  
     [0018] As shown in FIG. 2, pneumatic gun  28  includes a frame  32  with a forward end  36 , a rearward end  38 , and an exterior surface  40 . Penetrating the lower portion of frame  32  is all access port  42 . Extending longitudinally within frame  32  are a lower cavity  44 , which is defined by a lower-cavity sidewall  48 , and an upper cavity  52  that is disposed above and aligned with the lower cavity. An intercavity passageway  56  couples lower cavity  44  in fluid communication with upper cavity  52 . In upper cavity  52  is disposed a bolt  60 , which is penetrated internally by a bolt propulsion gas passageway  64 . Forward of bolt  60 , within a gun firing chamber  66 , is disposed a paintball  68 , which is shown in position to be propelled forward and expelled from pneumatic gun  28  by a release of compressed gas, as explained below.  
     [0019] Referring again to FIG. 2, valve assembly  24  is disposed within lower cavity  44 . Forward of valve assembly  24  within lower cavity  44  is a gas reservoir  72  that receives compressed gas from a gas cylinder  76 . Rearward of valve assembly  24 , within lower cavity  44 , is a recock chamber  80 . A hammer  84  is slidably translatable and for 0  (such as bumps) are bright regions, and the other regions are dull regions II. Under actual measurement and calculation, the aperture ratio of the MVA pixel is 47%, better than the traditional MVA pixel, 30%, shown in FIG. 1. Therefore, the aperture ratio is improved 57%, and a high resolution LCD with MVA pixels can be obtained.  
     [0020]FIG. 5 shows a top view of the MVA pixels. The liquid crystal molecules at the left red dot tilt in a bottom right direction ( ) and a top right direction ( ), and the liquid crystal molecules at the middle red (R) dot tilt in a top left direction ( ) and in a bottom left direction ( ). Therefore, four domains are obtained with two pixel regions, and a wide view angle display is achieved.  
     [0021] The foregoing description of the preferred embodiments of this invention has been presented for purposes of illustration and description. Obvious modifications or variations are possible in light of the above teaching. The embodiments were chosen and described to provide the best illustration of the principles of this invention and its practical application to thereby enable those skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the present invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.