Abstract:
A front and rear compound liquid crystal display includes a liquid crystal film which is selectively disposed in front of or behind an image display unit. The liquid crystal film can be controlled in a transparent, translucent or opaque state. In case the liquid crystal film is disposed in front of the image display unit, when the liquid crystal film is in the opaque state, it can function as a white board; when the liquid crystal film is in the transparent state, it can display the content of the image display unit. In case the liquid crystal film is disposed behind the image display unit, when the liquid crystal film is in the transparent state, it has visual penetration; when the liquid crystal film is in the opaque state, it can function as a reflection plate for the image of the image display unit to be displayed clearly.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a display, and more particularly to a front and rear compound liquid crystal display. 
         [0003]    2. Description of the Prior Art 
         [0004]    A conventional liquid crystal display to display image is composed of an image display unit, a backlight board and a guide light source. For the image to be displayed clearly and to have a vivid contrast, the backlight board doesn&#39;t have visual penetration. When the guide light source is off, the backlight board is dark. When the guide light source is on, the backlight board is white. The guide light source shoots its light to the front of the liquid crystal display. 
         [0005]    However, when the conventional liquid crystal display is not used, it usually stands at a very conspicuous position. Thus, the entire environment is slightly awkward, and it may hinder the vision. The conventional liquid crystal display cannot provide other functions and takes up a lot of space when it is not used. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve this problem. 
       SUMMARY OF THE INVENTION 
       [0006]    The primary object of the present invention is to provide a front and rear compound liquid crystal display. A liquid crystal film is selectively disposed in front of or behind an image display unit. By using the liquid crystal film to be in a transparent or opaque state, the liquid crystal film can function as a backlight board. It can be in a transparent state, not blocking the vision, when it doesn&#39;t display the image. Alternatively, the liquid crystal film can function as a white board when it doesn&#39;t display the image to be in a milky nebulized opaque state. The front and rear compound liquid crystal display provides multiple functions when it doesn&#39;t display image. 
         [0007]    In order to achieve the aforesaid object, the front and rear compound liquid crystal display of the present invention comprises a liquid crystal film. The liquid crystal film can control its transparency by means of voltage. The liquid crystal film is controlled by electrifying to be high transparent state or opaque. One side of the liquid crystal film is provided with an image display unit. The image display unit is adapted to display image. Another side of the liquid crystal film is provided with a panel member. A frame is provided at the circumferential sides of the liquid crystal film, the image display unit and the panel member to connect and fix the liquid crystal film, the image display unit and the panel member. 
         [0008]    The front and rear compound liquid crystal display of the present invention provides the liquid crystal film which can be controlled in a transparent or opaque state. The liquid crystal film is selectively disposed in front of or behind the image display unit. In case the liquid crystal film is disposed behind the image display unit, the liquid crystal film functions as a backlight board when the image display unit displays the image and is in the opaque state, alternatively, the liquid crystal film has visual penetration, not blocking the vision, when the image display unit doesn&#39;t display the image and is in the transparent state. In case the liquid crystal film is disposed in front of the image display unit, the liquid crystal film will function as a white board when the image display unit doesn&#39;t display the image to be in a milky nebulized opaque state. The front and rear compound liquid crystal display provides multiple functions when it doesn&#39;t display image. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a sectional view according to a first embodiment of the present invention; 
           [0010]      FIG. 2  is a schematic view showing the guide light source according to the first embodiment of the present invention; 
           [0011]      FIG. 3  is a schematic view showing the first embodiment of the present invention when in use; 
           [0012]      FIG. 4  is a sectional view according to a second embodiment of the present invention; and 
           [0013]      FIG. 5  is a schematic view showing the second embodiment of the present invention when in use. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]    Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings. 
         [0015]      FIG. 1  is a sectional view according to a first embodiment of the present invention.  FIG. 2  is a schematic view showing the guide light source according to the first embodiment of the present invention. The present invention discloses a front and rear compound liquid crystal display  100 . The front and rear compound liquid crystal display  100  comprises a liquid crystal film  10 , an image display unit  20 , a guide light source  30 , a panel member  50 , and a frame  60 . 
         [0016]    The liquid crystal film  10  comprises a liquid crystal layer  11  and two transparent conductive films  12 . The two transparent conductive films  12  are respectively disposed at two opposing sides of the liquid crystal layer  11 . The liquid crystal layer  11  can control its transparency by means of voltage. The liquid crystal layer  11  is controlled by electrifying to be a high transparent state or an opaque state. In the present invention, when the liquid crystal film  10  is not electrified, the liquid crystal molecules of the liquid crystal layer  11  are arranged disorderly and randomly for the light passing through the liquid crystal film  10  to be refracted and scattered, such that the appearance of the liquid crystal film  10  is in a milky even nebulized opaque state. When the transparent conductive films  12  of the liquid crystal film  10  are electrified, the liquid crystal molecules of the liquid crystal layer  11  are arranged in a single direction due to the function of the electric field for the parallel light to pass through the liquid crystal film  10  smoothly, such that the appearance of the liquid crystal film  10  is in a high transparent state. In this way, the liquid crystal film  10  is controlled by electrifying to be a high transparent state or an opaque state. This is only one embodiment of the present invention, but not limited to. The present invention can elect a liquid crystal film  10  for the parallel light to pass through the liquid crystal film  10  smoothly when the liquid crystal film  10  is not electrified, such that the appearance of the liquid crystal film  10  is in a high transparent state. When the liquid crystal film  10  is electrified, the light passing through the liquid crystal film  10  will be refracted and scattered so that the appearance of the liquid crystal film  10  is in a milky even nebulized opaque state. 
         [0017]    The image display unit  20  is disposed at one side of the liquid crystal film  10 . The image display unit  20  is adapted to display image. In the first embodiment of the present invention, the image display unit  20  is a liquid crystal display (LCD)  21 . The liquid crystal display  21  is a glass liquid crystal display and has visual penetration. The liquid crystal display  21  is disposed at the front side of the liquid crystal film  10  in a parallel manner. 
         [0018]    The guide light source  30  is disposed at the circumferential side of the image display unit  20 . The shooting direction of the guide light source  30  is toward the liquid crystal film  10 . In the first embodiment of the present invention, the guide light source  30  is disposed around the circumferential edge of the image display unit  20  along the radial direction of the image display unit  20 . As shown in  FIG. 2 , the guide light source  30  comprises a reflection board  31  and a plurality of LED (light emitting diode) light sources  32 . The reflection board  31  has a strip shape and is disposed along the circumferential edge of the image display unit  20 . The reflection board  31  has a bottom board  311  in a long axis direction thereof. The LED light sources  32  are spaced and fixed on the bottom board  311  in the long axis direction. The reflection board  31  further has a pair of wing boards  312  at two sides of the bottom board  311  extending in the long axis direction. One of the pair of the wing boards  312  is fixed on the image display unit  20 , such that the reflection board  31  is obliquely disposed at the circumferential edge of the image display unit  20  and the LED light sources  32  on the bottom board  311  face the liquid crystal film  10  to shoot light evenly on the liquid crystal film  10  so as to enhance the color of the image from the image display unit  20 . 
         [0019]    The panel member  50  is pervious to light. The panel member  50  is disposed at another side of the liquid crystal film  10 , namely, at the side opposite the image display unit  20 . In the first embodiment of the present invention, the panel member  50  is a transparent plastic panel  51 . The panel member  50  is parallelly disposed at the rear side of the liquid crystal film  10 . 
         [0020]    The frame  60  is disposed at the circumferential sides of the liquid crystal film  10 , the image display unit  20  and the panel member  50  to connect and fix the liquid crystal film  10 , the image display unit  20  and the panel member  50 . Referring to  FIG. 2 , the other of the pair of wing boards  312 , relative to the wing board fixed on the image display unit  20 , is fixed on the frame  60 . That is to say, one of the pair of wing boards  312  extending along the two sides of the bottom board  311  of the reflection board  31  is fixed on the frame  60 , and the other of the pair of wing boards  312  is fixed on the image display unit  20 . 
         [0021]      FIG. 3  is a schematic view showing the first embodiment of the present invention when in use. In the first embodiment of the present invention, the front and rear compound liquid crystal display  100  is disposed between the passenger seat and the driver seat of a taxi. This is just one embodiment, but not limited to. The front and rear compound liquid crystal display  100  can be used to display image. The liquid crystal film  10  is in an outage state and the transparent conductive films  12  of the liquid crystal film  10  are not electrified, so that the liquid crystal molecules of the liquid crystal layer  11  are arranged randomly and the liquid crystal film  10  is in a milky even nebulized opaque state as the backlight board of the image display unit  20 . Thus, the image display unit  20  can display the image clearly. 
         [0022]    When the front and rear compound liquid crystal display  100  doesn&#39;t display the image, the transparent conductive films  12  of the liquid crystal film  10  are electrified for the liquid crystal film  10  to be in an electrified state. The liquid crystal molecules of the liquid crystal layer  11  are arranged in a single direction due to the function of the electric field, such that the liquid crystal film  10  is in a high transparent state. The front and rear compound liquid crystal display  100  has visual penetration, not blocking the vision of the passenger and the driver. 
         [0023]    Accordingly, the front and rear compound liquid crystal display  100  can use the electrochromic technology to display the image to a transparent partition or window directly, or to provide an advertisement, to televise, or to display instant information. The front and rear compound liquid crystal display  100  has the properties of penetration and reflection to provide an innovated display. 
         [0024]      FIG. 4  is a sectional view according to a second embodiment of the present invention. The second embodiment is substantially similar to the first embodiment with the exceptions described hereinafter. The image display unit  20  is parallelly disposed at the rear side of the liquid crystal film  10 . The panel member  50  is parallelly disposed at the front side of the liquid crystal film  10 . The image display unit  20  is a liquid crystal display module (LCM)  22 . The liquid crystal display module  22  comprises a liquid crystal display  221  and a back light source  222 . In the second embodiment of the present invention, there is no need for the guide light source. The panel member  50  is a capacitance inductive panel  52 . The capacitance inductive panel  52  has a touch display function. Wherein, the touch function of the capacitance inductive panel  52  is a capacitance touch to cooperate with a capacitance touch system for executing touch. This is just one embodiment, but not limited to. The capacitance inductive panel  52  can select an optical inductive device to cooperate with an infrared LED for sensing. 
         [0025]    It is noted that the liquid crystal display module  22  of the second embodiment of the present invention can be replaced with a traditional liquid crystal display. 
         [0026]      FIG. 5  is a schematic view showing the second embodiment of the present invention when in use. In the second embodiment of the present invention, the front and rear compound liquid crystal display  100  uses the liquid crystal display module  22  composed of the liquid crystal display  221  and the back light source  222  to display the image clearly. When the front and rear compound liquid crystal display  100  needs to display the image, the transparent conductive films  12  of the liquid crystal film  10  are electrified for the liquid crystal film  10  to be in an electrified state. The liquid crystal molecules of the liquid crystal layer  11  are arranged in a single direction due to the function of the electric field, such that the liquid crystal film  10  is in a high transparent state to have visual penetration, not blocking the vision. The front and rear compound liquid crystal display  100  has visual penetration, not blocking the vision of the passenger and the driver. The liquid crystal display module  22  can display the image clearly. 
         [0027]    When the front and rear compound liquid crystal display  100  doesn&#39;t display the image, the liquid crystal film  10  is in an outage state and the transparent conductive films  12  of the liquid crystal film  10  are not electrified, so that the liquid crystal molecules of the liquid crystal layer  11  are arranged randomly and the liquid crystal film  10  is in a milky even nebulized opaque state. The front and rear compound liquid crystal display  100  can function as a white board, and the capacitance inductive board  52  is used to support the touch display function. 
         [0028]    Furthermore, the front and rear compound liquid crystal display  100  of the second embodiment of the present invention is disposed on a support  200 . The bottom of the support  200  is provided with a plurality of wheels  300  so that the front and rear compound liquid crystal display  100  can be moved conveniently for use. 
         [0029]    It is noted that the front and rear compound liquid crystal display  100  has a simple structure and can be manufactured at a very low cost. If the front and rear compound liquid crystal display  100  is applied to a smart display device, it is advantageous to the price. Besides, the optical performance has its advantage according to its unique display characteristic and cooperates with liquid crystal film  10  to be used for different applications of reflection and penetration. 
         [0030]    The features and expected effects of the present invention are described as follows: 
         [0031]    The front and rear compound liquid crystal display  100  of the present invention uses the liquid crystal film  10  as the backlight board for the front and rear compound liquid crystal display  100  to have visual penetration. When it doesn&#39;t display the image, it is in a transparent state, not blocking the vision. By using the liquid crystal film  10 , it can function as a white board when it doesn&#39;t display the image to be in a milky nebulized opaque state. 
         [0032]    Although particular embodiments of the present invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the present invention. Accordingly, the present invention is not to be limited except as by the appended claims.