Abstract:
An exemplary liquid crystal panel includes a first substrate, a second substrate parallel to the first substrate, and a liquid crystal layer between the first substrate and the second substrate. The second substrate includes color units and OLED units provided at substantially a same layer thereat, and the OLED units and the color units are alternately arranged. An LCD including the liquid crystal panel is also provided.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a liquid crystal panel that includes a plurality of organic light emitting display (OLED) units provided at a color filter substrate thereof, and a liquid crystal display (LCD) including the liquid crystal panel. 
       GENERAL BACKGROUND 
       [0002]    Recently, LCDs that are light and thin and have low power consumption characteristics have been widely used in office automation equipment, video units, and the like. 
         [0003]    Referring to  FIG. 3 , a typical transmissive liquid crystal panel  1  includes a color filter substrate  11 , a thin film transistor (TFT) substrate  12  parallel to the color filter substrate  11 , and a liquid crystal layer  13  sandwiched between the two substrates  11 ,  12 . 
         [0004]    A plurality of pixel electrodes (not shown) are formed at an inner surface (not labeled) of the TFT substrate  12 , generally opposite to the color filter substrate  11 . The color filter substrate  11  includes a plurality of color units  152 , black matrix units  153 , and a transparent conductive layer (not labeled) formed thereat. The color units  152  and the black matrix units  153  are respectively formed at an inner surface (not labeled) of the color filter substrate  11 , which inner surface is generally opposite to the TFT substrate  12 . The color units  152  respectively correspond to the pixel electrodes of the TFT substrate  12 . Each color unit  152  is separated from its neighboring color units  152  by the black matrix units  153 , in order to avoid color mixing. 
         [0005]    In operation of the transmissive liquid crystal panel  1 , light beams pass through the TFT substrate  12  and the liquid crystal layer  13 , and reach the color units  152  and the black matrix units  153  of the color filter substrate  11 . The light beams reaching the black matrix units  153  are absorbed by the black matrix units  153 . The light beams reaching the color units  152  emit from the color filter substrate  11  after being filtered by the color units  152 . Many light beams are absorbed by the black matrix units  153 , and the brightness of the light beams filtered by the color units  152  is also reduced. Overall, the brightness of the light beams emitting from the color filter substrate  11  may be significantly low, particularly when the transmissive liquid crystal panel  1  is controlled to display white images. Thus, a contrast of the transmissive liquid crystal panel  1  is low, and an optical performance of a transmissive LCD (not shown) employing the transmissive liquid crystal panel  1  is correspondingly low. 
         [0006]    What is needed, therefore, is a liquid crystal panel that can circumvent, overcome or at least mitigate the above-described difficulties. What is also needed is an LCD including the liquid crystal panel. 
       SUMMARY OF THE INVENTION 
       [0007]    In an exemplary embodiment, a liquid crystal panel includes a first substrate, a second substrate parallel to the first substrate, and a liquid crystal layer between the first substrate and the second substrate. The second substrate includes color units and OLED units provided at substantially a same layer thereat, and the OLED units and the color units are alternately arranged. An LCD including the liquid crystal panel is also provided. 
         [0008]    Other aspects, novel features and advantages will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of at least one embodiment of the present invention. In the drawings, like reference numerals designate corresponding parts throughout various views, and all the views are schematic. 
           [0010]      FIG. 1  is a side cross-sectional view of part of an LCD according to an exemplary embodiment of the present invention, the LCD including a liquid crystal panel that has a color filter substrate and a plurality of OLED units on the color filter substrate. 
           [0011]      FIG. 2  is essentially an enlarged, side cross-sectional view of one of the OLED units on the color filter substrate of  FIG. 1 . 
           [0012]      FIG. 3  is a side cross-sectional view of part of a conventional liquid crystal panel. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0013]    Reference will now be made to the drawings to describe various embodiments of the present invention in detail. 
         [0014]    Referring to  FIG. 1 , an LCD  200  according to an exemplary embodiment of the present invention is shown. The LCD  200  includes a liquid crystal panel  220 , and a backlight module  210  for providing light beams to the liquid crystal panel  220 . 
         [0015]    The liquid crystal panel  220  is a transmissive liquid crystal panel, and includes a TFT substrate  230 , a color filter substrate  240  parallel to the TFT substrate  230 , and a liquid crystal layer  254  sandwiched between the two substrates  230 ,  240 . A plurality of TFTs  255  and pixel electrodes  256  are alternately formed at an inner surface (not labeled) of the TFT substrate  230 , generally opposite to the color filter substrate  240 . 
         [0016]    The color filter substrate  240  includes a plurality of OLED units  2510 , a plurality of dielectric units  2511 , a plurality of color units  2521 , and a transparent conductive layer  253 . The OLED units  2510  and the color units  2521  are alternately formed at an inner surface (not labeled) of the color filter substrate  240 , generally opposite to the TFT substrate  230 . The color units  2521  include a plurality of different-colored color units. Each of the color units  2521  is spaced from its neighboring color units  2521  by the OLED units  2510 , in order to avoid color mixing. In the illustrated embodiment, the color units  2521  includes a plurality of red, green, and blue (RGB) color units, and can filter light beams passing therethrough. The OLED units  2510  are respectively covered by the dielectric units  2511 . The color units  2521  and the dielectric units  2511  are covered by the transparent conductive layer  253 . The transparent conductive layer  253  is generally made of transparent material, such as indium tin oxide (ITO) or indium zinc oxide (IZO). The dielectric units  2511  are preferably made from insulation materials. 
         [0017]    One OLED unit  2510  covered by the corresponding dielectric unit  2511 , one TFT  255  corresponding to the OLED unit  2510 , and liquid crystal molecules of the liquid crystal layer  254  between the OLED unit  2510  and the TFT  255  cooperatively define an OLED region  251 . One color unit  2521 , one pixel electrode  256  corresponding to the color unit  2521 , and liquid crystal molecules of the liquid crystal layer  254  between the color unit  2521  and the pixel electrode  256  cooperatively define an LCD region  252 . One OLED region  251  and one adjacent LCD region  252  cooperatively define a pixel region  250 . That is, the liquid crystal panel  220  can be considered to include a plurality of pixel regions  250 , each including an OLED region  251  and an LCD region  252 . 
         [0018]    Referring also to  FIG. 2 , each OLED unit  2510  includes a metallic anode layer  2518 , a hole injection layer (HIL)  2517 , a hole transfer layer (HTL)  2516 , an organic emission layer  2515 , an electron transfer layer (ETL)  2514 , an electron injection layer (EIL)  2513 , and a metallic cathode layer  2512 , arranged in that order from bottom to top. The metallic anode layer  2518  is formed on the inner surface of the color filter substrate  240 . The dielectric unit  2511  covers the respective metallic cathode layer  2512  of the OLED unit  2510 , and helps to smooth the metallic cathode layer  2512 . When the metallic anode layer  2518  and the metallic cathode layer  2512  have a potential applied thereto, the OLED unit  2510  responds to the potential by emitting light beams. 
         [0019]    In operation of the LCD  200 , the backlight module  210  functions as a planar light source. Light beams emit from the backlight module  210  and reach the liquid crystal panel  220 . The light beams pass through the TFT substrate  230  and the liquid crystal layer  254 , and reach the color units  2521  and the OLED units  2510  covered by the dielectric units  2511 . When one pixel region  250  is controlled to display a darkest gray level, the OLED unit  2510  of the pixel region  250  acts as a conventional black matrix unit. That is, the light beams reaching the OLED unit  2510  of the pixel region  250  are absorbed by the OLED unit  2510 . The light beams reaching the color unit  2521  of the pixel region  250  are filtered thereby, and emit from the color filter substrate  240  with the particular color of the color unit  2521 . When the pixel region  250  is controlled to display a brightest gray level, the OLED unit  2510  of the pixel region  250  acts as a light beam provider. That is, the metallic anode layer  2518  and the metallic cathode layer  2512  of the OLED unit  2510  have a controllable potential applied thereto, and the OLED unit  2510  responds to the potential by emitting white light beams with a maximum brightness. Therefore, a brightness of the light beams emitting from said pixel region  250  is improved. When the pixel region  250  is controlled to display another gray level between the darkest gray level and the brightest gray level, the potential applied to the metallic anode layer  2518  and the metallic cathode layer  2512  of the OLED unit  2510  is suitably controlled to provide white light beams with the desired brightness. The other pixel regions  250  of the liquid crystal panel  220  function similarly to said pixel region  250 . The above-described operations can be realized with a driving circuit (not shown) provided for driving the liquid crystal panel  220 . 
         [0020]    In summary, the OLED units  2510  of the liquid crystal panel  220  not only take the place of conventional black matrix units to separate the color units  2521  and absorb incident light beams, but also provide white light beams with controllable brightness for the liquid crystal panel  220 . In addition, the LCD  200  can attain an optimal display effect by configuring an area ratio of the OLED region  251  and the LCD region  252  according to particular display and optical requirements. In the exemplary embodiment, the area ratio of the OLED region  251  to the corresponding pixel region  250  is configured to be in the range from 10% to 90%. Thus the liquid crystal panel  220  can achieve a high luminance and a high contrast by the utilization of the OLED units  2510 , and an optical performance of the LCD  200  is correspondingly improved. 
         [0021]    In alternative embodiments, the liquid crystal panel  220  can be a transflective liquid crystal panel or a reflective liquid crystal panel. In each such case, the OLED units  2510  are suitably configured to function in the transflective liquid crystal display or the reflective liquid crystal display. 
         [0022]    It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.