Abstract:
A light shielding apparatus using magnetic microbeads and a method of the same are disclosed. The light shielding apparatus includes a cycling chamber defined by two transparent substrates, a fluid filled in the cycling chamber, a plurality of magnetic microbeads suspended in the fluid, and a cycling motor connected to the cycling chamber. The cycling motor has a magnetic device. When the magnetic device is powered on, the magnetic microbeads are collected by the magnetic device and restricted in the cycling motor; so that, ambient light pass through the cycling chamber and the two transparent substrates. When the magnetic device is turned off, the magnetic microbeads are recycled with the fluid in the cycling chamber and the cycling motor to block ambient light.

Description:
TECHNICAL FIELD 
       [0001]    The disclosure is related to a light shielding apparatus and particularly to a light shielding apparatus using magnetic microbeads to shield light and a method of the same. 
       DESCRIPTION OF RELATED ART 
       [0002]    Light shielding apparatus having regular shapes are used in common place. For example, window coverings including curtains, window blinds, and window shades are used for shielding sunlight from entering houses. Window coverings are moved to a predetermined location by operating accessory parts to block out sunlight instantly. 
         [0003]    Light shielding apparatuses are also found in displays with liquid crystal display (LCD) panels, constructed by a liquid crystal layer sandwiched by two indium tin oxide (ITO) glasses. The liquid crystals are twisted by applying a bias between the ITO glasses to allow lights from backlight modules to pass for displaying a picture. Since the light shielding apparatuses in LCD panels arc constructed with ITO, the manufacturing cost is correspondingly increased with the size of LCD panels. In addition to high manufacturing cost, operating the light shielding apparatuses in LCD panels is energy-consuming. It is required to provide a light shielding apparatus to overcome these shortcomings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    The components in the drawing are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of a light shielding apparatus and a method of the same. 
           [0005]      FIG. 1  and  FIG. 2  are schematic diagrams showing a light shielding apparatus according to a preferred embodiment of the disclosure. 
           [0006]      FIG. 3  and  FIG. 4  are schematic diagrams showing an operation status of the light shielding apparatus when a magnetic device is turned on. 
           [0007]      FIG. 5  and  FIG. 6  are schematic diagrams showing another operation status of the light shielding apparatus when the magnetic device is turned off. 
           [0008]      FIG. 7  shows a method of shielding light using the light shielding apparatus of the disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    The disclosure will be described with references to the accompanying diagrams. 
         [0010]      FIG. 1  and  FIG. 2  show schematic diagrams of a light shielding apparatus according to a preferred embodiment of the disclosure.  FIG. 2  is a side view drawing from the right side of  FIG. 1 . 
         [0011]    The light shielding apparatus  10  includes a first transparent substrate  121 , a second transparent substrate  122 , a cycling chamber  14 , a fluid  16 , a cycling motor  18 , and a plurality of microbeads  20 . The first transparent substrate  121  and the second transparent substrate  122  are installed parallel to each other. In the present embodiment, the first transparent substrate  121  and the second transparent substrate  122  may be made of glass, plastic material, or other materials depending on the wavelength of the light. In addition, installing a holding device surrounding edges of the first transparent substrate  121  and the second transparent substrate  122  is allowable. The holding device may include a frame, a spacer, or an adhesive glue as it must maintain a predetermined gap between the first transparent substrate  121  and the second transparent substrate  122 . The first transparent substrate  121 , the second transparent substrate  122 , and the holding device define the cycling chamber  14 . In some embodiments, the cycling chamber  14  is defined by first transparent substrate  121  and the second transparent substrate  122  without the holding device. For example, the first transparent substrate  121  has portions extending from the edges of the first transparent substrate  121 , and the portions are assembled to the second substrate  122  to form a closed space defining the cycling chamber  14 . 
         [0012]    The cycling chamber  16  is filled with the fluid  16  and the microbeads  20  are suspended in the fluid  16 . The fluid  16  may be water, aqueous solution, gel, or other transparent materials with good fluidity. The microbeads  20  are particles with magnetic materials and are capable of reflecting or absorbing lights striking on them. Each of the microbeads  20  has a diameter substantially between 1 nanometer to 2000 nanometers. 
         [0013]    The cycling chamber  14  connects the cycling motor  18  by an exit  141  and an entrance  142 . When the cycling motor  18  is in operation, the fluid  16  leaves the cycling chamber  14  from the exit  14 , enters the cycling motor  18 . The fluid  16  recycles through the cycling motor  18  and into the cycling chamber  14  via the entrance  142 . The cycling motor  18  drives the fluid  16  to recycle within the cycling chamber  14  and the cycling motor  18 . The velocity of the fluid  16  may be modulated as required. 
         [0014]    The cycling motor  18  has a magnetic device  181 . When the magnetic device  181  is turned on, the microbeads  20  in the fluid  16  are attracted by magnetic force and collected within the cycling motor  18 . 
         [0015]      FIG. 3  and  FIG. 4  are schematic diagrams showing an operation status of the light shielding apparatus  10  when the magnetic device  181  is turned on.  FIG. 4  is a side view drawing from the right side of  FIG. 3 . When the cycling motor  18  is in operation, the microbeads  20  move within the cycling chamber  14  and the cycling motor  18 , simultaneously with the flowing fluid  16 , meanwhile, the magnetic device  181  is turned on to produce a magnetic field. Most of the microbeads  20  are therefore attracted and are collected within the cycling motor  18  and the fluid  16  recycles through the cycling chamber  14 . When the strength of the magnetic field is over a threshold, only the fluid  16  recycles within the cycling motor  18  and the cycling chamber  14 . As shown in  FIG. 4 , a first light  22 , which is ambient light in the environment where the light shielding apparatus  10  is placed, strikes an outer surface  1211  of the first transparent substrate  121 , passes through the fluid  16  in the cycling chamber  14  and leaves from an outer surface  1221  of the second transparent substrate  122 . The first light  22  easily passes through the cycling chamber  14  from one side to the other side. 
         [0016]      FIG. 5  and  FIG. 6  are schematic diagrams showing another operation status of the light shielding apparatus  10  when the magnetic device  181  is turned off.  FIG. 6  is a side view drawing from the right side of  FIG. 5 . When the cycling motor  18  is in operation, the microbeads  20  move within the cycling chamber  14  and the cycling motor  18 , simultaneously with the flowing fluid  16 . In addition, the magnetic device  181  is turned off, the microbeads  20  keep flowing within the fluid  16  in the cycling motor  18 . The microbeads  20  are dispersed in the fluid  16  and therefore are dispersed in the cycling chamber  14  and the cycling motor  18 . These microbeads  20  block or absorb ambient light and hinder ambient light from passing through the cycling chamber  14  from one side to the other side. 
         [0017]    The penetration rate of ambient light is correlated to the number of the microbeads  20 , the concentration of the microbeads  20  in the fluid  14 , and the distance of the gap between the first transparent substrate  121  and the second transparent substrate  122 . In other words, the number of the microbeads  20 , the concentration of the microbeads  20  in the fluid  16 , or the distance of the gap between the first transparent substrate  121  and the second transparent substrate  122  is greater; the penetration rate of ambient lights is lower. On the other hand, the strength of the magnetic field provided by the magnetic device  181  is greater; the penetration rate of ambient light is lower. In some circumstances, light shielding efficiency of the light shielding apparatus  10  ma be up to 99%. For example, when the magnetic device  181  is turned off, the microbeads  20  flow with the fluid  16  and recycles in the cycling chamber  14  and the cycling motor  18 , second light  24 , which is ambient light from the environment where the light shielding apparatus is placed, strikes the outer surface  1211  of the first transparent substrate  121 , and are absorbed or blocked by the microbeads  20  (see  FIG. 6 ). No light passes through the cycling chamber  14 , the second transparent substrate  122 , and the outer surface  1221  of the second transparent substrate  122 . The second light  24  is substantially blocked by magnetic beads  20  in the cycling chamber  14  from passing through one side to the other side. 
         [0018]    Accordingly, the disclosure provides a light shielding apparatus using microbeads and a method of shielding light by turning on or off the magnetic device  181 . The method of shielding light is shown in  FIG. 7 . In step  100 , a light shielding apparatus  10  of the disclosure is provided. Elements of the light shielding apparatus  10  are described in previous paragraphs. In step  110 , the magnetic device  181  is turned on and the magnetic beads  20  are collected in the cycling motor  18  (also referring to  FIGS. 3-4 ). Therefore, ambient light (e.g. the first light  22 ) from the environment is allowed to pass through the first transparent substrate  121 , the cycling chamber  14  and the second transparent substrate  122 . In step  120 , the magnetic device  181  is turned off and the magnetic heads  20  are dispersed in the cycling chamber  14  (also referring to  FIGS. 5-6 ). Accordingly, ambient light (e.g. the second light  24 ) from the environment is blocked by the magnetic beads  20  in the cycling chamber. In addition, step  110  and step  120  may be repeated in a predetermined frequency as required. 
         [0019]    The light shielding apparatus of the disclosure and the method of the same may be applied as smart glass using as a construction material for windows or partitions. The light shielding apparatus and the method may also be applied as a component of LCD panels in TV to control passage of lights coming from the backlight modules. The use of the light shielding apparatus of the disclosure and the method may be applied to many other elements managing light. Furthermore, the light shielding apparatus of the disclosure and the method may also apply to provide gray scales. 
         [0020]    It to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set fourth 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 the 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.