Abstract:
The present invention proposes a color display utilizing combinations of four colors, wherein full-color images are obtained by controlling gray-scale contrast of a plurality of pixels each having four colors. The four colors are two primary colors and two contrastive colors complementary to them, e.g., the red and its complementary color—cyan and the green and its complementary color—magenta. The present invention can enhance the color fullness and the delicacy of images without increasing the cost and changing the design of structure.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a display and, more particularly, to a color display capable of displaying full color.  
         BACKGROUND OF THE INVENTION  
         [0002]    Displays are inevitable equipments of the present information society. They play the roles as output devices for showing pictures and texts. Along with the development of information products toward compactness, flat panel displays become the mainstream of electronic application products gradually. In general flat panel displays, no matter what kind of displaying means is adopted, color images are obtained using various kinds of variations and combinations of the three primary colors of red, green, and blue.  
           [0003]    With a liquid crystal display (LCD) as an example, each pixel on a liquid crystal panel is divided into three sub-pixels, which show the three primary colors of red, green and blue through a color filter, respectively. Full-color displaying is achieved through mixing different ratios of the three primary colors. Although this kind of using the three primary colors can achieve the object of full-color displaying, the colors that can be displayed are limited in the triangle enclosed by the three primary colors. For those customers having higher requirement of colors, the colors that can be displayed are not satisfactory, and quality of color images is rougher and unnatural. The present invention aims to propose a color display utilizing combinations of four to enhance the quality of color images.  
         SUMMARY OF THE INVENTION  
         [0004]    The primary object of the present invention is to propose a color display utilizing combinations of four colors to display color images so as to enhance the color fullness and to have good quality of color images.  
           [0005]    Another object of the present invention is to propose a color utilizing combinations of four colors, wherein the count of ICs used in a color driving module thereof is comparable to that used in a display composed of the three primary colors. Therefore, delicacy of colors can be enhanced without increasing the cost.  
           [0006]    According to the present invention, the color displaying way of a color display is accomplished by controlling variations and combinations of brightness and gray-scale contrast of a plurality of pixels each having four colors to achieve the object of full-color displaying. The four colors are a first primary color and its complementary color, and a second primary color and its complementary color, respectively.  
           [0007]    The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawings, in which: 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a structure diagram of a liquid crystal display;  
         [0009]    [0009]FIG. 2 is a diagram of a color driving module according to an embodiment of the present invention;  
         [0010]    [0010]FIG. 3 is a diagram of a color driving module according to another embodiment of the present invention; and  
         [0011]    [0011]FIG. 4 is a structure diagram of an organic light emitting diode. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0012]    The present invention is characterized in that color images are obtained using variations and combinations of four colors. The four colors are selected from two different primary colors and two contrastive colors complementary to them. The characteristics of the present invention will be illustrated by describing an LCD and an OLED below.  
         [0013]    As shown in FIG. 1, an LCD  10  comprises two transparent substrates  12  and  12 ′ with a color filter  14 , a transparent electrode plate  16 , an orientation film  18 , a liquid crystal layer  20 , an orientation film  18 ′, and a transparent electrode plate  16 ′ sandwiched in between from top to bottom in this order. Liquid crystal molecules will rotate and arrange according the direction specified by the orientation films  18  and  18 ′. Two polarizers  22  and  22 ′ cover the outer surfaces of the two transparent substrates  12  and  12 ′, respectively. A plurality of sub-pixels  24  selected from the four colors are uniformly arranged on the color filter  14 . The four colors are a first primary color  26  and its complementary color  28 , and a second primary color  30  and its complementary color  32 , respectively. The arrangement of the sub-pixels  24  of different colors is shown in FIG. 2. The colors of the sub-pixels  24  are selected from the four colors of red (R), cyan (C), green (G), and magenta (M). Each column and each row of the sub-pixels  24  show uniform and alternate arrangement of the four colors of R, C, G, and M. The above primary colors and their complementary colors can be selected from any two groups of the red and its complementary color—cyan, the blue and its complementary color—yellow, and the green and its complementary color—magenta.  
         [0014]    The arrangement of the four colors of each column and each row of the sub-pixels  24  of the color filter  14  is uniform so that good white balance can be achieved. Therefore, the background of a display can be conditioned to a very good white color. Moreover, the range of colors that can be conditioned according to different ratios of the above four colors are a quadrangle with an area much larger than that of the triangle enclosed by the three primary colors. Higher color fullness can be obtained by the colors displayed in the present invention than those composed of the three primary colors. Therefore, a color display of the present invention can show vivid, natural, beautiful, and colorful images.  
         [0015]    A signal scan line  34  and a data transmission line  36  are provided for each row and each column of the sub-pixels  24 . The signal scan lines  34  and the data transmission lines  36  are driven by a set of signal scan driving parts  38  and a set of data transmission driving parts  40 , respectively. The data transmission lines  36  and the signal scan lines  34  are modules composed of indium tin oxide (ITO) at the upper and lower layers, and are uniformly arranged on the transparent electrode plates  16  and  16 ′, respectively. The design of the color driving module is similar to that of a driving module that generates color images using the three primary colors. Moreover, the counts of semiconductor driving parts used are commensurate. Therefore, the present invention can enhance the color fullness and improve the quality of image without increasing the cost. The signal scan driving part  38  and the data transmission driving part  40  can be separate active IC devices.  
         [0016]    Furthermore, the arrangement of the sub-pixels  24  having different colors can be the way shown in FIG. 3. Each column of the sub-pixels  24  is formed by uniformly arranging the first primary color  26  and its complementary color  28 , and the adjacent columns of the sub pixels  24  are formed by uniformly arranging the second primary color  30  and its complementary color  32 . Although this kind of arrangement will easily let the background of a display have a color, higher color fullness can be obtained with the colors conditioned by the four colors.  
         [0017]    As shown in FIG. 4, an OLED  42  comprises a glass substrate  44  with an ITO electrode layer  46 , a protection film  48 , a light-emitting layer  50 , and a metal electrode layer  52  disposed thereon in this order. Four kinds of light-emitting materials of organic molecules are uniformly coated on the light-emitting layer  50 . The four kinds of light-emitting materials can emit out two kinds of primary colors and their complementary colors. When electrified, electrons of outer layers of organic molecules will be excited to a higher energy level and then drop to the lower energy level, emitting out photons having an energy of this difference of energy levels. Therefore, the pixels can show colors. The arrangement and connection of the light-emitting materials are the same as those of the sub-pixels in the above LCD and thus will not be further described.  
         [0018]    To sum up, without increasing the cost, a color display utilizing combinations of four colors of the present invention can obtain vivid and natural full-color images having higher color fullness and no distortion, thereby satisfying those customers having higher requirement of colors.  
         [0019]    Although the present invention has been described with reference to the preferred embodiments thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.