Electronic paper printer

Abstract

An electronic paper printer is provided that is capable of describing display patterns properly and definitely on rewritable electronic paper. An electronic paper printer 1 has a describing head 3 for describing display patterns on electronic paper 2 capable of having display patterns rewritten thereto and erased therefrom, using electrophoresis, an erasing head 4 for erasing display patterns described on the electronic paper 2, a drive mechanism (not shown) for driving the describing head 3 and the erasing head 4 so that they turn, and a conveyor mechanism (not shown) for conveying the electronic paper 2. The describing head 3 is configured by a pair of drums 31 and 32 supported so that they freely turn. The erasing head 4 is configured by a pair of drums 41 and 42 supported so that they freely turn.

What is claimed is:  
     
         1 . An electronic paper printer for describing display patterns on electronic paper, comprising: 
 a plurality of capsules inside of which charged particles move, whereby colors are changed and display patterns are displayed; and    a head for describing display patterns on said electronic paper; wherein:    said charged particles inside said capsules are caused to move by applying an electric field to said electronic paper; and    portion of said head which contacts said electronic paper is given a curved shape.    
     
     
         2 . The electronic paper printer according to  claim 1 , wherein said head is configured by at least a pair of drums.  
     
     
         3 . The electronic paper printer according to  claim 2 , wherein at least one drum of said pair of drums has, on outer circumferential surface thereof, a plurality of pixel electrodes that form electric fields that are applied to said electronic paper.  
     
     
         4 . The electronic paper printer according to  claim 2 , wherein one drum of said pair of drums has, on outer circumferential surface thereof, a plurality of pixel electrodes that form electric fields that are applied to said electronic paper, and other drum thereof has, on outer circumferential surface thereof, a common electrode that forms said electric fields together with said pixel electrodes.  
     
     
         5 . The electronic paper printer according to  claim 3  or  4 , wherein said plurality of pixel electrodes is deployed in a matrix arrangement.  
     
     
         6 . The electronic paper printer according to  claim 3 ,  4 , or  5 , having a plurality of switching elements that can switch between forming and extinguishing the electric fields produced by the plurality of pixel electrodes.  
     
     
         7 . The electronic paper printer according to  claim 6 , wherein said switching elements are thin film transistors.  
     
     
         8 . An electronic paper printer for describing display patterns on electronic paper, comprising: 
 a plurality of capsules inside of which charged particles move, whereby colors are changed and display patterns are displayed; and    a drum-shaped head for describing display patterns on said electronic paper; wherein:    said charged particles inside said capsules are caused to move by applying an electric field to said electronic paper; and    configuration is such that said display patterns are described by patterns applied from said head to said electronic paper.    
     
     
         9 . The electronic paper printer according to anyone of  claims 1  to  8 , wherein said head has an erasing head for erasing display patterns described on said electronic paper and a describing head for describing display patterns on said electronic paper.  
     
     
         10 . The electronic paper printer according to any one of  claims 1  to  8 , wherein said head is configured so that overwriting is possible.  
     
     
         11 . An electronic paper printer for describing display patterns on electronic paper, comprising: 
 a plurality of capsules inside of which charged particles move, whereby colors are changed and display patterns are displayed;    a describing head for describing display patterns on said electronic paper; and    an erasing head for erasing display patterns described on said electronic paper; wherein:    portion or portions of said describing head and/or said erasing head that contact said electronic paper are given a curved shape.    
     
     
         12 . The electronic paper printer according to  claim 11 , wherein said erasing head is configured by a pair of drums having a single electrode on outer circumferential surfaces thereof.  
     
     
         13 . The electronic paper printer according to  claim 11 , wherein at least one head of said describing head and said erasing head is configured by a pair of drums.  
     
     
         14 . The electronic paper printer according to  claim 13 , wherein at least one drum of said pair of drums has, on outer circumferential surface thereof, a plurality of pixel electrodes that form electric fields that are applied to said electronic paper.  
     
     
         15 . The electronic paper printer according to  claim 13 , wherein one drum of said pair of drums has, on outer circumferential surface thereof, a plurality of pixel electrodes that form electric fields that are applied to said electronic paper, and other drum thereof has, on outer circumferential surface thereof, a common electrode that forms said electric fields together with said pixel electrodes.  
     
     
         16 . The electronic paper printer according to  claim 14  or  15 , wherein said plurality of pixel electrodes is deployed in a matrix arrangement.  
     
     
         17 . The electronic paper printer according to  claim 14 ,  15 , or  16 , having a plurality of switching elements that can switch between forming and extinguishing said electric fields produced by said plurality of pixel electrodes.  
     
     
         18 . The electronic paper printer according to  claim 17 , wherein said switching elements are thin film transistors.  
     
     
         19 . An electronic paper printer for describing display patterns on electronic paper, comprising: 
 a plurality of capsules inside of which charged particles move, whereby colors are changed and display patterns are displayed; and    an overwrite-capable head for describing display patterns on said electronic paper; wherein:    said charged particles inside said capsules are caused to move by applying an electric field to said electronic paper; and    portion of said head which contacts said electronic paper is given a curved shape.    
     
     
         20 . The electronic paper printer according to  claim 19 , wherein said head has a pair of drums, and each drum of said pair of drums has, on outer circumferential surface thereof, a plurality of pixel electrodes that form electric fields that are applied to said electronic paper.  
     
     
         21 . The electronic paper printer according to  claim 19 , wherein said head has a pair of drums, and one drum of said pair of drums has, on outer circumferential surface thereof, a plurality of pixel electrodes that form electric fields that are applied to said electronic paper, and other drum thereof has, on outer circumferential surface thereof, a common electrode that forms said electric fields together with said pixel electrodes.  
     
     
         22 . The electronic paper printer according to  claim 21 , configured such that two electric fields oriented in different directions between said common electrode and said pixel electrodes can be selectively formed by setting electrical potential of said common electrode at a prescribed value.  
     
     
         23 . The electronic paper printer according to any one of claims  20 ,  21 , or  22 , wherein said plurality of pixel electrodes is deployed in a matrix arrangement.  
     
     
         24 . The electronic paper printer according to any one of  claims 20  to  23 , having a plurality of switching elements that can switch between forming and extinguishing said electric fields produced by said plurality of pixel electrodes.  
     
     
         25 . The electronic paper printer according to  claim 24 , wherein said switching elements are thin film transistors.  
     
     
         26 . The electronic paper printer according to any one of  claims 1  to  25 , wherein said electronic paper has a base layer and an electronic ink layer, and said plurality of capsules is dispersed in said electronic ink layer.