Patent Publication Number: US-2012038968-A1

Title: Strenthened electrochromic reflection structure

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a reflection structure for controlling the intensity, the color, the phase, polarization or direction of the light from an independent light source; and more particularly to a strengthened electrochromic reflection structure. 
     2. Description of the Prior Art 
     Electrochromic material has the advantages of controllable penetration rate, fine memory effect, quick response, low driving voltage, long service life, and energy conservation. 
       FIG. 1  illustrates a conventional electrochromic structure for a rear-view mirror, as shown in  FIG. 2 , the conventional electrochromic structure  90  comprises a substrate  91 , a first conductive layer  92 , an electrochromic layer  93 , a second conductive layer  94  and a panel  95  that are superposed one upon another. The above conventional electrochromic structure for a rear-view mirror can prevent glare by changing reflectivity and light transmission with voltage according to the light intensity. 
     The present invention has arisen to mitigate and/or obviate the afore-described disadvantages. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a strengthened electrochromic reflection structure, the reflectivity of the strengthened electrochromic reflection structure is increased when light is emitted onto the front surface of the strengthened electrochromic reflection structure, and the back light transmission is improved when light is emitted on the back surface of the strengthened electrochromic reflection structure. 
     To achieve the above objective, a strengthened electrochromic reflection structure comprises a substrate, an interfacial layer, a reflection layer, a first conductive layer, an electrochromic layer, a second conductive layer and a panel. 
     The electrochromic layer, the second conductive layer and the panel together constitute an electrochromic structure. When being emitted onto the strengthened electrochromic reflection structure of the present invention, the light will be reflected out through the electrochromic structure by the reflection layer. The interfacial layer is made of the material selected from the group consisting of silicon dioxide, aluminum oxide, and magnesium fluoride. With the interfacial layer, the reflection layer and the substrate can be assuredly combined, and unwanted refraction or scattering can be reduced while the light passes through the interfacial layer, so that the information light emitted from the screen on the back surface of the strengthened electrochromic reflection structure can be effectively reflected by the strengthened electrochromic reflection structure and read by the user, improving the back light transmission. 
     Between the reflection layer and the first conductive layer is further provided a protecting layer, the protecting layer is made of the same material as the interfacial layer. The reflection layer and the reflection layer are made of materials having different densities to increase the reflectivity of the reflection layer effectively, consequently improving the reflectivity of the strengthened electrochromic reflection structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of a conventional electrochromic structure; 
         FIG. 2  is an operational view of the conventional electrochromic structure; 
         FIG. 3  is a cross-sectional view of a strengthened electrochromic reflection structure in accordance with the present invention; and 
         FIG. 4  is another cross-sectional view of the strengthened electrochromic reflection structure in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will be clearer from the following description when viewed together with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment in accordance with the present invention. 
     Referring to  FIGS. 3-5 , a strengthened electrochromic reflection structure  10  in accordance with a first embodiment of the present invention comprises a substrate  11 , an interfacial layer  12 , a reflection layer  13 , a first conductive layer  14 , an electrochromic layer  15 , a second conductive layer  16  and a panel  17 . The electrochromic layer  15 , the second conductive layer  16  and the panel  17  together constitute an electrochromic structure. 
     The substrate  11  is made of a material selected from the group consisting of glass, polycarbonate and polymethylmethacrylate. 
     The interfacial layer  12  is made of aluminum oxide and has a thickness ranged from 200 Å to 1800 Å. The interfacial layer  12  is combined onto the substrate  11 . The interfacial layer  12  can also be made of a material selected from the group consisting of silicon dioxide, indium tin oxide and magnesium fluoride. 
     The reflection later  13  is disposed on the interfacial layer  12  by metal coating and made of a material selected from the group consisting of silver having a purity higher than 4N, a silver-palladium alloy containing 3% palladium, a silver-palladium alloy containing 5% palladium, a silver-palladium-copper alloy containing 1% palladium and 2% copper, a silver-palladium-copper alloy containing 2% palladium and 1% copper, a silver-palladium-copper alloy containing 3% palladium or 5% palladium and 1% copper, a silver-copper alloy containing 3% copper, a platinum-silver alloy containing 2%, 4% or 7% platinum, a gold-silver alloy containing 2%, 4% or 7% gold. The reflection layer  13  has an electric resistance smaller than 5 Ω/cm 2  and a thickness ranged from 450 Å to 1000 Å. The reflection layer  13  is combined onto the interfacial layer  12 . 
     The first conductive layer  14  is made of a material selected from the group consisting of titanium zinc, titanium and titanium alloys. The first conductive layer  14  has a thickness ranged from 50 Å to 200 Å. The first conductive layer  14  is combined onto the reflection layer  13 . Alternatively, the first conductive layer  14  can also be made of a transparent conducting oxide selected from the group consisting of indium doped tin oxide, aluminum doped zinc oxide, gallium doped zinc oxide, fluorine-doped tin oxide, stannic oxide, and zinc oxide. The first conductive layer  14  is combined onto the reflection layer  13 . 
     The electrochromic layer  15  is combined onto the first conductive layer  14 , and the second conductive layer  16  is combined onto the electrochromic layer  15 . The panel  17  is combined onto the second conductive layer  16 . The above electrochromic layer  15 , the second conductive layer  16  and the panel  17  are the conventional structures, so no further explanations are provided herein. The substrate  11  of the strengthened electrochromic reflection structure  10  of the present invention is further provided on a back surface thereof with a screen  20 . The screen  20  emits information light onto the reflection structure  10 , and the information light will be reflected by the strengthened electrochromic reflection structure  10  and read by the user from the panel  17 . Since this is conventional art, no further discussion seems necessary. 
     With the arrangement of the substrate  11 , the interfacial layer  12  and the reflection layer  13 , the reflectivity and the back light transmission of the strengthened electrochromic reflection structure  10  in accordance with the present invention can be improved. 
     Alternatively, the interfacial layer  12  can also be a coating made of chromium or nickel chromium alloy and has a thickness ranged from 200 Å to 400 Å. The interfacial layer  12  is provided to form an interface strengthening the adhesive force between the substrate  11  and the reflection layer  13 . Due to its non-metallic structure having the metallic features, the interfacial layer  12  can assuredly combine the non-metallic substrate  11  and the metallic reflection layer  13  integrally, improving the product stability. 
     A light path of the strengthened electrochromic reflection structure  10  in accordance with the first embodiment of the present invention is described as follows: When light  30  pass through the electrochromic layer  15  from the panel  17  to the reflection layer  13 , a large proportion of the light  30  will be reflected out of the strengthened electrochromic reflection structure  10  by the reflection layer  13 . Since the interfacial layer  12  is made of a material having a density smaller than that of the reflection layer  13 , when the screen  20  on the back surface of the substrate  11  emits the information light, the information light will enter the interfacial layer  12  directly from the substrate  11  and then reach the reflection layer  13 , after that, the information light will pass through the reflection layer  13  in an accelerated manner and finally transmit out of the strengthened electrochromic reflection structure  10  of the present invention through the first conductive layer  14 , the electrochromic layer  15  and the second conductive layer  16 , thus providing a higher back light transmission while greatly reducing the light refraction and light scattering. 
     Referring to  FIG. 4 , a strengthened electrochromic reflection structure  10  in accordance with a second embodiment of the present invention comprises a substrate  11 , an interfacial layer  12 , a reflection layer  13 , a protecting layer  18 , a first conductive layer  14 , an electrochromic layer  15 , a second conductive layer  16  and a panel  17 . The substrate  11 , the interfacial layer  12 , the reflection layer  13 , the first conductive layer  14 , the electrochromic layer  15 , the second conductive layer  16 , and the panel  17  are the same as the corresponding elements of the previous embodiment in structure, but the interfacial layer  12  is made of pure aluminum having a purity higher than 4N. Between the reflection layer  13  and the first conductive layer  14  is disposed the protecting layer  18  which is made of the same material as the interfacial layer  12  in the previous embodiment, and the remaining layers of the second embodiment are made of the same materials as the previous embodiment. 
     A light path of the strengthened electrochromic reflection structure  10  in accordance with the second embodiment of the present invention is described as follows: When the light  30  are projected onto the protecting layer  18  and the reflection layer  13  from the panel  17  through the electrochromic layer  15 , although a large proportion of the light  30  are reflected out by the protecting layer  18 , since the density of the protecting layer  18  is smaller than that of the reflection layer  13 , the light  30  which enter the protecting layer  18  will be projected onto the reflection layer  13  in an accelerated manner and then reflected by the reflection layer  13 , avoiding the scattering loss before the reflection of the reflection layer  13  while effectively reflecting the light out. After being emitted from the screen  20 , the information light will pass through the substrate  11 , the interfacial layer  12 , the reflection layer  13 , the protecting layer  18 , the first conductive layer  14 , the electrochromic layer  15 , the second conductive layer  16  and the panel  17 , respectively, and will finally be read by the user. By such arrangements, it can be found that the reflectivity of the present invention can be improved if light is projected onto a front surface of the strengthened electrochromic reflection structure, while the light transmission can be improved if light is emitted from a back surface of the strengthened electrochromic reflection structure. 
     Our tests show that the reflectivity of the present invention can be improved due to the arrangement of the reflection layer  13  and the protecting layer  18 . For example, when the reflection layer  13  is made by aluminum plating, the reflectivity can be improved from 85% to 92%. Furthermore, the strengthened electrochromic reflection structure  10  in accordance with the present invention still has the electricity conductive function. 
     While we have shown and described various embodiments in accordance with the present invention, it is clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.