Patent Abstract:
A liquid crystal display panel (LCD) having display capability on both sides. The LCD comprises a liquid crystal module, a first front polarizer, a first rear polarizer, a first reflector, a second front polarizer, a second rear polarizer, and a second reflector. By replacing a portion of the original front polarizer with the first rear polarizer and the first reflector, and replacing a portion of the original rear polarizer and the original reflector with the first front polarizer, the LCD having display capability on both sides can be attained.

Full Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a liquid crystal display panel; in particular, to a liquid crystal display panel having display capability on both sides. 
     2. Description of the Related Art 
     Notebook computer manufacturers use a variety of liquid crystal display (LCD) panel types in the manufacture of notebook computers to reduce cost and to increase production levels. Recently, there is also a growing need for mobile is communication devices using the LCD panels. For example, the LCD panels can be applied in mobile phones and personal digital assistant (PDA) devices. 
     A conventional LCD panel  10  is shown in FIG. 1 a , FIG. 1 b  and FIG. 1 c . Numeral  11  represents a liquid crystal module. The liquid crystal module  11  comprises a substrate, liquid crystal molecules and other material. However, since the detail structure of the liquid crystal module  11  is irrelative to the characteristic of this invention and is well known by persons skilled in the art, their detail description is omitted. 
     The liquid crystal display module  11  is provided with a front polarizer  12  at one side and a rear polarizer  13  at the other side. Generally, the polarized axis of the front polarizer  12  and the polarized axis of the front polarizer  13  are perpendicular, and the alignment of the liquid crystal molecules in the liquid crystal module  11  is well controlled. Specifically, light passes through the polarizer  12 ,  13  by the arrangement of the polarizer  12 ,  13  and the alignment of the liquid crystal molecules in the liquid crystal module  11 . As a result, depending on whether the light passes through or not, different images are shown on the LCD panel  10 . 
     The rear polarizer  13  is provided with a reflector  14 . By means of the reflector  14 , characters and graphs can be shown on the front polarizer  12 . That is, viewing from a direction by an arrow A of FIG. 1 b , characters shown in FIG. 1 c  can be seen on the LCD panel  10 . 
     Furthermore, there is a need for mobile communication devices with an LCD panel having display capability on both sides. 
     For example, a PDA mobile phone  30  is shown in FIG. 2 a  and FIG. 2 b . The PDA mobile phone is a communication device with PDA function and mobile phone function. When a keyboard portion  31  and a display portion  32  combine, a first screen  33  of the display portion  32  is used as a screen for the mobile phone function. When a keyboard portion  31  and a display portion  32  separate, a second screen  34  of the display portion  32  is used as a screen for the PDA function. 
     However, in the conventional PDA mobile phone, two LCD panels are used as the first screen and the second screen respectively. Thus, the cost is increased, and the whole thickness is also increased. As a result, it is difficult to miniaturize the PDA mobile phone. 
     SUMMARY OF THE INVENTION 
     In order to address the disadvantages of the aforementioned LCD panel, the invention provides an LCD panel having display capability on both sides. 
     Another purpose of this invention is to minimize the thickness of a PDA mobile phone. 
     Accordingly, the invention provides a liquid crystal display panel. The LCD panel comprises a liquid crystal module, a first polarizer, a second polarizer, a first reflector, and a second reflector. The liquid crystal module is provided with a first surface and a second surface opposite to the first surface. The first polarizer is disposed on the first surface of the liquid crystal module, and the second polarizer is disposed on the second surface of the liquid crystal module. The first reflector is disposed on part of the first polarizer, and the second reflector is disposed on part of the second polarizer. The other part of the second polarizer and the first reflector overlap completely in a direction perpendicular to the first surface of the liquid crystal module. 
     Furthermore, the liquid crystal module comprises a substrate, and liquid crystal molecules. 
     In another preferred embodiment, this invention provides another liquid crystal display panel. The LCD panel comprises a liquid crystal module, a first front polarizer, a first rear polarizer, a first reflector, a second rear polarizer, a second front polarizer, and a second reflector. The liquid crystal module is provided with a first surface and a second surface opposite to the first surface, and the first front polarizer is disposed on one portion of the first surface of the liquid crystal module. The first rear polarizer is disposed on the second surface of the liquid crystal module. The first front polarizer and the first rear polarizer overlap completely in a direction perpendicular to the first surface of the liquid crystal module. The first reflector is disposed on the first rear polarizer, and the second rear polarizer is disposed on the other portion of the first surface of the liquid crystal module. The second front polarizer is disposed on the second surface of the liquid crystal module. The second front polarizer and the second rear polarizer overlap completely in a direction perpendicular to the first surface of the liquid crystal module. The second reflector is disposed on the second rear polarizer. 
     In another preferred embodiment, this invention provides another adapted for a PDA mobile phone having a first screen and a second screen. The LCD panel comprises a liquid crystal module, a first polarizer, a second polarizer, a first reflector, and a second reflector. The liquid crystal module is provided with a first surface and a second surface opposite to the first surface. The first polarizer is disposed on the first surface of the liquid crystal module, and the second polarizer is disposed on the second surface of the liquid crystal module. The first reflector is disposed on one portion of the first polarizer, and the second reflector is disposed on one portion of the second polarizer. The other portion of the second polarizer and the first reflector overlap completely in a direction perpendicular to the first surface of the liquid crystal module. The other portion of the first polarizer is used as the first screen, and the other portion of the second polarizer is used as the second screen. 
     In another preferred embodiment, this invention provides another adapted for a PDA mobile phone having a first screen and a second screen. The LCD panel comprises a liquid crystal module, a first front polarizer, a first rear polarizer, a first reflector, a second rear polarizer, a second front polarizer, and a second reflector. The liquid crystal module is provided with a first surface and a second surface opposite to the first surface. The first front polarizer is disposed on one portion of the first surface of the liquid crystal module and used as the first screen. The first rear polarizer is disposed on the second surface of the liquid crystal module. The first front polarizer and the first rear polarizer overlap completely in a direction perpendicular to the first surface of the liquid crystal module. The first reflector is disposed on the first rear polarizer, and the second rear polarizer is disposed on the other portion of the first surface of the liquid crystal module. The second front polarizer is disposed on the second surface of the liquid crystal module and used as the second screen. The second front polarizer and the second rear polarizer overlap completely in a direction perpendicular to the first surface of the liquid crystal module. The second reflector is disposed on the second rear polarizer. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is hereinafter described in detail with reference to the accompanying drawings in which: 
     FIG. 1 a  is a schematic view depicting a conventional LCD panel; 
     FIG. 1 b  is an enlarged view depicting a part D of FIG. 1 a;    
     FIG. 1 c  is a side diagram viewing from an arrow A of FIG. 1 b;    
     FIG. 2 a  and FIG. 2 b  are schematic views depicting a PDA mobile phone; 
     FIG. 3 a  is a schematic view depicting an LCD panel of a first embodiment as disclosed in this invention; 
     FIG. 3 b  is an enlarged view depicting a part E of FIG. 3 a;    
     FIG. 3 c  is a side diagram viewing from an arrow B of FIG. 3 b  and FIG. 4 b;    
     FIG. 3 d  is a side diagram viewing from an arrow C of FIG.  3   b  and FIG. 4 b;    
     FIG. 4 a  is a schematic view depicting an LCD panel of a second embodiment as disclosed in this invention; and 
     FIG. 4 b  is an enlarged view depicting a part F of FIG. 4 a.   
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     First Embodiment 
     Referring to FIG. 3 a , FIG. 3 b , FIG. 3 c  and FIG. 3 d , a liquid crystal display panel  20 , as disclosed in a first embodiment of this invention, comprises a liquid crystal module  21 , a first polarizer  22 , a second polarizer  23 , a first reflector  24 , and a second reflector  25 . Like the conventional device, the liquid crystal module  21  comprises a substrate, liquid crystal molecules and other material, and is provided with a first surface  211  and a second surface  212  opposite to the first surface  211 . 
     The first polarizer  22  is disposed on the first surface  211  of the liquid crystal module  21 , and the second polarizer  23  is disposed on the second surface  212  of the liquid crystal module  21 . The first reflector  24  is disposed on part of the first polarizer  22 , and the second reflector  25  is disposed on part of the second polarizer  23 . The first reflector  24  and the second reflector  25  do not overlap in a direction perpendicular to the first surface  211  of the liquid crystal module  21 . In other words, the liquid crystal module  21  is divided into an upper portion and a lower portion by a dash line X. The first reflector  24  is disposed on the upper portion of one side of the liquid crystal module  21 , and the second reflector  25  is disposed on the lower portion of the other side of the liquid crystal module  21 . 
     Since the second reflector  25  is disposed on the second polarizer  23 , characters can be shown on part, without disposing the first reflector  24 , of the first polarizer  22 . That is, viewing from a direction by an arrow B of FIG. 3 b , characters shown in FIG. 3 c  can be seen on the LCD panel  20 . As well, since the first reflector  24  is disposed on the first polarizer  22 , characters can be shown on part, without disposing the second reflector  25 , of the second polarizer  23 . That is, viewing from a direction by an arrow C of FIG. 3 b , characters shown in FIG. 3 d  can be seen on the LCD panel  20 . 
     Thus, by means of one LCD panel, characters can be shown on both the upper portion of one side and the lower portion of the other side. As a result, the cost is reduced, and the whole weight and thickness of product using the LCD panel is also reduced. 
     When the LCD panel in this embodiment is applied in the PDA mobile phone as shown in FIG. 2 a , part, without disposing the second reflector  25 , of the second polarizer  23  can be used as the first screen for mobile phone function, and part, without disposing the first reflector  24 , of the first polarizer  22  can be used as the second screen for PDA function. 
     It is noted that characters, shown on the LCD panel  20  in FIG. 3 d , are abnormal; that is, they are mirror images of normal characters. However, they can be changed to normal characters by means of software. Since this method is well known by persons skilled in the art, their description is omitted. 
     In addition, it is understood that the proportion between the first screen and the second screen of the PDA mobile phone can be changed by adjusting the size of the reflectors  24 ,  25 . 
     Second Embodiment 
     Referring to FIG. 4 a , FIG. 4 b , FIG. 3 c  and FIG. 3 d , a liquid crystal display panel  40 , as disclosed in a second embodiment of this invention, comprises a liquid crystal module  41 , a first front polarizer  46 , a first rear polarizer  42 , a first reflector  44 , a second rear polarizer  43 , a second front polarizer  47 , and a second reflector  45 . Like the first embodiment, the liquid crystal module  41  comprises a substrate, liquid crystal molecules and other material, and is provided with a first surface  411  and a second surface  412  opposite to the first surface  411 . 
     The liquid crystal module  41  is divided into an upper portion and a lower portion by a dash line X. The first front polarizer  46  is disposed on the upper portion of the first surface  411  of the liquid crystal module  41 , and the second rear polarizer  43  is disposed on the lower portion of the first surface  411  of the liquid crystal module  41 . The first rear polarizer  42  is disposed on the upper portion of the second surface  412  of the liquid crystal module  41 , and the second front polarizer  47  is disposed on the lower portion of the second surface  412  of the liquid crystal module  41 . The first reflector  44  is disposed on the first rear polarizer  42 , and the second reflector  45  is disposed on the second rear polarizer  43 . That is, the first front polarizer  46 , the first rear polarizer  42  and the first reflector  44  overlap completely in a direction perpendicular to the first surface  411  of the liquid crystal module  41 . As well, the second front polarizer  47 , the second rear polarizer  43  and the second reflector  45  overlap completely in a direction perpendicular to the first surface  411  of the liquid crystal module  41 . 
     Since the second reflector  45  is disposed on the second rear polarizer  43 , characters can be shown on the second front polarizer  47 . That is, viewing from a direction by an arrow B of FIG. 4 b , characters shown in FIG. 3 c  can be seen on the LCD panel  40 . As well, since the first reflector  44  is disposed on the first rear polarizer  42 , characters can be shown on the first front polarizer  46 . That is, viewing from a direction by an arrow C of FIG. 4 b , characters shown in FIG. 3 d  can be seen on the LCD panel  40 . 
     Thus, by means of one LCD panel, characters can be shown on both the upper portion of one side and the lower portion of the other side. As a result, the cost is reduced, and the whole weight and thickness of product using the LCD panel is also reduced. 
     When the LCD panel in this embodiment is applied in the PDA mobile phone as shown in FIG. 2 a  and FIG. 2 b , the first front polarizer  46  can be used as the first screen for mobile phone function, and the second front polarizer  47  can be used as the second screen for PDA function. 
     It is noted that characters, shown on the LCD panel  40  in FIG. 3 d , are abnormal; that is, they are mirror images of normal characters. However, they can be changed to normal characters by means of software. Since this method is well known by persons skilled in the art, their description is omitted. 
     In addition, it is understood that the proportion between the first screen and the second screen of the PDA mobile phone can be changed by adjusting the size of the polarizer and the reflectors. 
     While the invention has been particularly shown and described with reference to a preferred embodiment, it will be readily appreciated by those of ordinary skill in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. It is intended that the claims be interpreted to cover the disclosed embodiment, those alternatives which have been discussed above, and all equivalents thereto.

Technology Classification (CPC): 7