Contact imaging system

Abstract

The contact imaging system allows the contact area of an object impressed upon the surface of the contact imaging system to emit light in a pattern corresponding to the contact area making it possible to render an image of the contact area. The contact imaging system has a luminescence layer on top of a transparent electrode. When the object to be imaged contacts the luminescence layer and is held at ground potential relative to the transparent electrode, an electric field is created in the luminescence layer in a pattern corresponding to the contact pattern. The electric field causes the luminescence layer to emit a light image of the contact pattern. The luminescence layer and the transparent electrode are adjacent to a light sensing layer. The light sensing layer receives the light generated at the luminescence layer, and converts that light into a corresponding electric signal. The light sensing element or layer can consist of a PN junction diode having a solar cell structure, a photo transistor, a camera, a scanner, a position sensitive detector, a charge couple device or a CMOS sensor. The contact imaging system can also include a stray light shield which may include a dark pigment to block stay light, and may also include a water repellent and/or abrasive resistant shield layer on top of the luminescence layer.

1 . A contact imaging system, comprising: 
 a light sensing element;    a transparent insulating layer overlaying said light sensing element;    a transparent electrode layer overlaying said transparent insulating layer;    a luminescence layer overlaying said transparent electrode layer; and    a stray light shield layer overlaying said luminescence layer, wherein the luminescence layer and the electrode layer are configured such that an electric field can be applied between an object to be imaged and said transparent electrode layer.    
     
     
         2 . The contact imaging system according to  claim 1 , further comprising a transparent adhesive disposed between said light sensing element and said transparent insulating layer.  
     
     
         3 . The contact imaging system according to  claim 1 , wherein said light sensing element comprising a PN junction diode.  
     
     
         4 . The contact imaging system according to  claim 3 , wherein said PN junction diode comprises: 
 a lower electrode;    an N-type silicon layer overlaying said lower electrode;    an intrinsic silicon layer overlaying said N-type silicon layer;    a P-type silicon layer overlaying said intrinsic silicon layer; and,    a transparent electrode overlaying said P-type silicon layer.    
     
     
         5 . The contact imaging system according to  claim 4 , wherein said PN junction diode is configured to be biased by a reversed direction voltage.  
     
     
         6 . The contact imaging system according to  claim 1 , wherein said light sensing element comprises a charge coupled device.  
     
     
         7 . The contact imaging system according to  claim 1 , wherein said light sensing element comprises a complementary metal oxide semiconductor (CMOS) image sensor.  
     
     
         8 . The contact imaging system according to  claim 1 , wherein said light sensing element comprises a photo transistor.  
     
     
         9 . The contact imaging system according to  claim 1 , wherein said light sensing element comprises a position sensitive detector.  
     
     
         10 . The contact imaging system according to  claim 1 , wherein said light sensing element comprises a camera.  
     
     
         11 . The contact imaging system according to  claim 1 , wherein said light sensing element comprises a scanner.  
     
     
         12 . The contact imaging system according to  claim 1 , wherein said luminescence layer includes a dark pigment that acts to enhance contrast.  
     
     
         13 . The contact imaging system according to  claim 12 , further comprising a penetrating control layer formed between said luminescence layer and said stray light shield layer, wherein said stray light shield layer includes a dark pigment, and wherein said penetrating control layer is configured to limit an amount of said dark pigment that passes from said stray light shield layer to said luminescence layer.  
     
     
         14 . The contact imaging system according to  claim 13 , wherein said stray light shield layer comprises: 
 a first layer adjacent the penetrating control layer that includes said dark pigment; and    a second layer overlying said first layer, wherein said second layer is configured to block exterior light.    
     
     
         15 . The contact imaging system according to  claim 1 , wherein said light sensing elements comprises a two dimensional array of light sensing elements.  
     
     
         16 . A contact imaging system, comprising: 
 a light sensing element;    a transparent insulating layer overlaying said light sensing element;    a transparent electrode layer overlaying said transparent insulating layer;    a luminescence layer overlaying said transparent electrode layer; and    a protective layer overlaying said luminescence layer, wherein said luminescence layer and said electrode layer are configured such that an electric field can be applied between an object to be imaged and said transparent electrode layer.    
     
     
         17 . The contact imaging system according to  claim 16 , wherein said light sensing element comprises a PN junction diode.  
     
     
         18 . The contact imaging system according to  claim 17 , wherein said PN junction diode comprises: 
 a lower electrode;    an N-type silicon layer overlaying said lower electrode;    an intrinsic silicon layer overlaying said N-type silicon layer;    a P-type silicon layer overlaying said intrinsic silicon layer; and,    a transparent electrode overlaying said P-type silicon layer.    
     
     
         19 . The contact imaging system according to  claim 16 , wherein said PN junction diode is configured to be biased by a reversed direction voltage.  
     
     
         20 . The contact imaging system according to  claim 16 , wherein said light sensing element comprises a charge coupled device.  
     
     
         21 . The contact imaging system according to  claim 16 , wherein said light sensing element comprises a complementary oxide semiconductor image sensor.  
     
     
         22 . The contact imaging system according to  claim 16 , wherein said light sensing element comprises a photo transistor.  
     
     
         23 . The contact imaging system according to  claim 16 , wherein said light sensing element comprises a position sensitive detector.  
     
     
         24 . The contact imaging system according to  claim 16 , wherein said light sensing element comprises a camera.  
     
     
         25 . The contact imaging system according to  claim 16 , wherein said light sensing element comprises a scanner.  
     
     
         26 . The contact imaging system according to  claim 16 , wherein said protective layer is hydrophobic.  
     
     
         27 . The contact imaging system according to  claim 16 , wherein said protective layer is abrasion resistant.  
     
     
         28 . The contact imaging system according to  claim 16 , further comprising a shield layer disposed between said protective layer and said luminescence layer, wherein said shield layer is configured to block exterior light.  
     
     
         29 . The contact imaging system comprising: 
 a light sensing element;    a transparent insulating layer overlaying said light sensing element;    a transparent electrode layer overlaying said transparent insulating layer; and    a luminescence layer overlaying said transparent electrode layer, wherein the electrode layer is configured such that an electric field can be applied between an object to be imaged and said transparent electrode layer, and wherein said electric field causes said luminescence layer to luminesce when the object to be imaged is brought adjacent to said luminescence layer.    
     
     
         30 . The contact imaging system according to  claim 29 , further comprising a transparent adhesive disposed between said light sensing element and said transparent insulating layer.  
     
     
         31 . The contact imaging system according to  claim 29 , wherein said light sensing element comprises a PN junction diode.  
     
     
         32 . The contact imaging system according to  claim 31 , wherein said PN junction diode comprises: 
 a lower electrode;    an N-type silicon layer overlaying said lower electrode;    an intrinsic silicon layer overlaying said N-type silicon layer;    a P-type silicon layer overlaying said intrinsic silicon layer; and,    a transparent electrode overlaying said P-type silicon layer.    
     
     
         33 . The contact imaging system according to  claim 29 , wherein said light sensing element comprises a charge coupled device.  
     
     
         34 . The contact imaging system according to  claim 29 , wherein said light sensing element comprises a complementary metal oxide semiconductor image sensor.  
     
     
         35 . The contact imaging system according to  claim 29 , wherein said light sensing element comprises a photo transistor.  
     
     
         36 . The contact imaging system according to  claim 29 , wherein said light sensing element comprises a position sensitive detector.  
     
     
         37 . The contact imaging system according to  claim 29 , wherein said light sensing element comprises a camera.  
     
     
         38 . The contact imaging system according to  claim 29 , wherein said light sensing element comprises a scanner.  
     
     
         39 . The contact imaging system of  claim 29 , further comprising: 
 a shield layer that includes a dark pigment; and    a penetrating control layer located between said shield layer and said luminescence layer, wherein said penetrating control layer is configured to limit an amount of the dark pigment in the shield layer that migrates to the luminescence layer.    
     
     
         40 . The contact imaging system of  claim 29 , further comprising a protective layer overlaying the shield layer, wherein the protective layer is abrasion resistant and repels moisture.