Abstract:
A transflective liquid crystal panel includes a first substrate, a second substrate, a liquid crystal layer sandwiched between the two substrates, color filter film, transparent units, reflective units, and a solid color film. The color filter film is disposed on a surface of the first substrate adjacent to the liquid crystal layer. The color filter film includes filter units. The transparent units are configured for transmitting light. The reflective units are configured for reflecting light. Each filter unit corresponds to a transparent unit and a reflective unit. The solid color film covers at least the transparent units. A permeability of the solid color film relative to a predetermined color light waves exceeds that relative to light waves of other colors.

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to transflective liquid crystal panels, and particularly to a transflective liquid crystal panel having a solid color layer formed on one substrate thereof. 
     2. Description of Related Art 
     Because liquid crystal displays (LCDs) have the advantages of portability, low power consumption, and low radiation, they are widely used in portable devices such as notebooks, personal digital assistants (PDAs), video cameras, and others. LCDs can utilize transparent, reflective, and transflective display technologies. Transflective LCDs conserve considerable power by utilizing a part of available environmental light. 
     Referring to  FIG. 5 , a typical transflective liquid crystal panel  10  includes a first substrate  120 , a color filter film  130 , a second substrate  170 , a multiplicity of transparent electrodes  160 , a multiplicity of reflective electrodes  150 , and a liquid crystal layer  140 . 
     The first substrate  120  is disposed generally opposite to the second substrate  170 . The liquid crystal layer  140  is sandwiched between the first substrate  120  and the second substrate  170 . The color filter film  130  is disposed on an inner surface of the first substrate  120  adjacent to the liquid crystal layer  140 . Each transparent electrode  160  is disposed on an inner surface of the second substrate  170  corresponding to a transparent region (not labeled). Each reflective electrode  150  is disposed on the inner surface of the second substrate  170  corresponding to a reflective region (not labeled). 
     The color filter film  130  includes a plurality of filter units (not labeled) such as red, green, and blue filter units, although  FIG. 5  shows only one blue filter unit. The filter unit corresponds to the combined area of the transparent electrode  160  and the reflective electrode  150 . The transparent electrode  160  can transmit light originating from a backlight module (not shown). The reflective electrode  150  can reflect environmental light originating from the front (top) of the transflective liquid crystal panel  10 . 
     Light from the backlight module is transmitted through the second substrate  170 , the transparent electrode  160 , the liquid crystal layer  140 , the color filter film  130 , and the first substrate  120  in order. The environmental light enters the first substrate  120 , and is transmitted through the color filter film  130  and the liquid crystal layer  140 . The environmental light reaches a surface of the reflective electrode  150 , and is reflected thereby through the liquid crystal layer  140 , the color filter film  130 , and the first substrate  120  again. 
     While light corresponding to the reflective region passes through the color filter film  130  twice, light corresponding to the transparent region only passes through the color filter film  130  once. Thus, chroma corresponding to the reflective region is substantially distinct from that corresponding to the transparent region. Accordingly, the color performance of the transflective liquid crystal panel  10  is liable to be unsatisfactory. 
     What is needed, therefore, is a transflective liquid crystal panel that can overcome the described limitations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-section of a pixel region of a transflective liquid crystal panel according to a first embodiment of the present invention. 
         FIG. 2  is a cross-section of a pixel region of a transflective liquid crystal panel according to a second embodiment of the present invention. 
         FIG. 3  is a cross-section of a pixel region of a transflective liquid crystal panel according to a third embodiment of the present invention. 
         FIG. 4  is a cross-section of a pixel region of a transflective liquid crystal panel according to a fourth embodiment of the present invention. 
         FIG. 5  is a cross-section of a pixel region of a frequently used transflective liquid crystal panel. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made to the drawings to describe various embodiments of the present invention in detail. 
       FIG. 1  is a cross-section of a pixel region of a transflective liquid crystal panel according to a first embodiment of the present invention. The transflective liquid crystal panel  20  includes a first substrate  220 , a color filter film  230 , a second substrate  270 , a plurality of transparent electrodes  260 , a plurality of reflective electrodes  250 , a plurality of solid color films (layers)  290 , and a liquid crystal layer  240 . 
     The first substrate  220  is disposed generally opposite to the second substrate  270 . The liquid crystal layer  240  is sandwiched between the first substrate  220  and the second substrate  270 . The color filter film  230  is disposed on an inner surface of the first substrate  220  adjacent to the liquid crystal layer  240 . Each transparent electrode  260  is disposed on an inner surface of the second substrate  270  corresponding to a transparent region (not labeled). Each reflective electrode  250  is disposed on the inner surface of the second substrate  270  corresponding to a reflective region (not labeled). Each solid color film  290  is disposed on the corresponding transparent electrode  260 . The transparent electrode  260  transmits light originating from a backlight module (not shown). The reflective electrode  250  reflects environmental light originating from outside a front (top) of the transflective liquid crystal panel  20 . 
     The color filter film  230  includes a plurality of color filter units (not labeled, hereinafter “filter units”) such as red, green, and blue filter units. In  FIG. 1 , only one filter unit, for example, a blue filter unit, is shown. The filter unit corresponds to the combined area of the transparent electrode  260  and the reflective electrode  250 . A plurality of bumps (reflective structures)  251  are formed on a surface of the reflective electrode  250  adjacent to the liquid crystal layer  240 . The bumps  251 , each having a same tapered profile, are uniformly sized and arranged uniformly. In the illustrated embodiment, each of the bumps  251  has an isosceles triangle cross-section, and the bumps  251  are continuously arranged. The bumps  251  reflect and scatter light. A total thickness of the solid color film  290  and the transparent electrode  260  is substantially equal to a thickness of the reflective electrode  250 . Permeability of the solid color film  290  relative to blue light exceeds that relative to light of other colors. Thus, blue chroma of the light, after passing through the solid color film  290 , increases. The solid color film  290  functions as a chroma compensating film. 
     Light emitted from the backlight module passes through the second substrate  270 , the transparent electrode  260 , the solid color film  290 , the liquid crystal layer  240 , the color filter film  230 , and the first substrate  220  in order. Environmental light enters the first substrate  220 , and passes through the color filter film  230  and the liquid crystal layer  240 , reaching the surface of the reflective electrode  250  and being reflected by the bumps  251 . The reflected environmental light passes through the liquid crystal layer  240 , the color filter film  230 , and the first substrate  220  again. 
     Compared with other commonly deployed transflective liquid crystal panels, the transflective liquid crystal panel  20  includes a solid color film  290  disposed at each of the transparent regions. When the filter unit of the pixel region is a blue filter unit, the permeability of the solid color film  290  relative to blue light waves exceeds that relative to light waves of other colors. Thus, the blue chroma of the light after passing through the solid color film  290  increases. While the environmental light passes through the color filter film  230  twice, the light from the backlight module passes through the solid color film  290  once only, and passes through the color filter film  230  once only. That is, the chroma of the light from the backlight module is compensated by the solid color film  290 . Therefore, the chroma of the output light corresponding to the transparent region is substantially the same as that of the output light corresponding to the reflective region. 
     In the case where another pixel region of the color filter film  230  has a red filter unit, the permeability of the corresponding solid color film  290  relative to red light waves exceeds that relative to light waves of other colors. In the case where still another pixel region of the color filter film  230  has a green filter unit, the permeability of the corresponding solid color film  290  relative to green light waves exceeds that relative to light waves of other colors. 
     Referring to  FIG. 2 , a cross-section of a pixel region of a transflective liquid crystal panel  30  according to a second embodiment of the present invention is shown. The transflective liquid crystal panel  30  differs from the transflective liquid crystal panel  20  in that a single solid color film  390  is disposed on both transparent electrodes  360  and reflective electrodes  350 , adjacent to a liquid crystal layer  340 . The solid color film  390  is a blue color film. A thickness H of the solid color film  390  corresponding to each transparent electrode  360  is more than twice a thickness h of the solid color film  390  corresponding to each reflective electrode  350 . An entire surface of the solid color film  390  adjacent to the liquid crystal layer  340  is smooth. 
     Unlike the transflective liquid crystal panel  20 , the solid color film  390  is disposed on an entire surface of both the transparent electrode  360  and the reflective electrode  350  in each pixel region of the transflective liquid crystal panel  30 . The solid color film  390  makes images of the transflective liquid crystal panel  30  prone to blue coloring. Higher visual tendency toward blue, compared to red or green, makes the transflective liquid crystal panel  30  preferable for viewing. Moreover, the entire surface of the solid color film  390  adjacent to the liquid crystal layer  340  is smooth, so a mask process for manufacturing the solid color film  390  is not needed. 
       FIG. 3  is a cross-section of a pixel region of a transflective liquid crystal panel  40  according to a third embodiment of the present invention. The transflective liquid crystal panel  40  includes a first substrate  420 , a color filter film  430 , a second substrate  470 , a plurality of pixel electrodes  460 , a transflective film  452 , a plurality of solid color films  490 , and a liquid crystal layer  440 . 
     The first substrate  420  is disposed generally opposite to the second substrate  470 . The liquid crystal layer  440  is sandwiched between the first substrate  420  and the second substrate  470 . The color filter film  430  is disposed on an inner surface of the first substrate  420  adjacent to the liquid crystal layer  440 . The color filter film  430  includes a plurality of filter units (not labeled) such as red, green, and blue filter units. In  FIG. 3 , only one filter unit, a blue filter unit, is shown. Each filter unit corresponds to the pixel electrode  460 . 
     In each pixel region, the transflective film  452  includes a transparent part  453  and a reflective part  454 . The transparent part  453  is disposed on an inner surface of the second substrate  470  corresponding to a transparent region (not labeled). The reflective part  454  is disposed on the inner surface of the second substrate  470  corresponding to a reflective region (not labeled). The solid color film  490  is disposed on the transparent part  453 . A permeability of the solid color film  490  relative to blue light waves exceeds that relative to light waves of other colors. The transparent part  453  transmits light originating from a backlight module (not shown). The reflective part  454  reflects environmental light originating from outside a front (top) of the transflective liquid crystal panel  40 . The transparent part  453  is thinner than the reflective part  454 . A total thickness of the transparent part  453  and the solid color film  490  is equal to a thickness of the reflective part  454 . A plurality of bumps (reflective structures)  451  are formed on a surface of the reflective part  454  facing away from the liquid crystal layer  440 . Each bump  451  has a same tapered profile, and reflects and scatters light. In the illustrated embodiment, the bumps  451  are uniformly sized and arranged uniformly. Each of the bumps  251  has an isosceles triangle cross-section, and the bumps  251  are continuously arranged. 
     The transflective liquid crystal panel  40  has advantages similar to those of the transflective liquid crystal panel  20 . That is, the chroma of the output light corresponding to the transparent region is substantially the same as that of the output light corresponding to the reflective region. 
       FIG. 4  is a cross-section of a pixel region of a transflective liquid crystal panel  50  according to a fourth embodiment of the present invention. The transflective liquid crystal panel  50  differs from the transflective liquid crystal panel  40  in that a single solid color film  590  is disposed on a surface of a transflective film  552 , adjacent to a liquid crystal layer  540 . The solid color film  590  is a blue color film. In each pixel region, the transflective film  552  includes a transparent part  553  and a reflective part  554 . A thickness H of the solid color film  590  corresponding to the transparent part  553  is more than twice a thickness h of the solid color film  590  corresponding to the reflective part  554 . An entire surface of the solid color film  590  adjacent to the liquid crystal layer  540  is smooth. The transflective liquid crystal panel  50  has advantages similar to those of the transflective liquid crystal panel  30  and the transflective liquid crystal panel  40 . 
     In further and/or alternative embodiments, when there is a single solid color film, the solid color film can be red or green to satisfy different uses. In general, whether there are plural solid color films or whether there is a single solid color film, materials and/or colors of the solid color film(s) are selected to ensure that chroma difference between a transparent region and a reflective region in each pixel region is compensated or adjusted as desired. 
     It is to be understood that even though numerous characteristics and advantages of the present embodiments have been set out in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.