Optical compensatory sheet producing method and apparatus, thermal treating method and apparatus, and dust removing method and apparatus

Abstract

An optical compensatory sheet producing apparatus produces an optical compensatory sheet having a liquid crystal layer. In the apparatus, a rubbing unit is supplied with resin film having a first layer including resin, and subjects the first layer to a rubbing process, so as to form an orientation layer. A dust remover removes dust from the orientation layer by use of liquid such as perfluorocarbon, to which the orientation layer is insoluble. A liquid crystal layer coater is disposed downstream from the dust remover, for coating the orientation layer with coating liquid including liquid crystalline compound, so that the liquid crystal layer is formed.

1 . A thermal treating apparatus for a coating layer formed by coating traveling web with coating liquid, comprising: 
 at least one hot air supply unit for blowing said coating layer with hot air; and    at least one exhaust unit, disposed upstream or downstream from said hot air supply unit in a traveling direction of said web, for sucking said hot air from said coating layer.    
   
   
       2 . A thermal treating apparatus as defined in  claim 1 , further comprising a controller for adjusting a first flow speed at which said hot air is supplied by said hot air supply unit, and a second flow speed at which said hot air is sucked by said exhaust unit.  
   
   
       3 . A thermal treating apparatus as defined in  claim 2 , wherein said hot air supply unit includes: 
 a hot air generator for generating said hot air;    an air blow opening disposed to face said coating layer;    a supply fan or blower, controlled by said controller, for sending said hot air from said hot air generator through said air blow opening;    said exhaust unit includes:    an exhaust opening disposed to face said coating layer;    an exhaust fan or blower, controlled by said controller, for sending said hot air from said exhaust opening.    
   
   
       4 . A thermal treating apparatus as defined in  claim 3 , wherein said controller controls said supply fan or blower and said exhaust fan or blower, to keep a flow speed of said hot air equal to or lower than 1 m/sec with reference to a web width direction crosswise to said traveling direction.  
   
   
       5 . A thermal treating apparatus as defined in  claim 4 , wherein as viewed in said web width direction, said air blow opening has 1.05-2 times as great a size as a width of said web.  
   
   
       6 . A thermal treating apparatus as defined in  claim 5 , further comprising a flow speed sensor for detecting said flow speed of said hot air on said coating layer; 
 wherein said controller controls said supply fan or blower and said exhaust fan or Lower according to said flow speed.    
   
   
       7 . A thermal treating apparatus as defined in  claim 6 , wherein said air blow opening includes plural air blow nozzles arranged in said traveling direction.  
   
   
       8 . A thermal treating apparatus as defined in  claim 7 , wherein said air blow nozzles are arranged in a matrix manner.  
   
   
       9 . A thermal treating apparatus as defined in  claim 7 , wherein said air blow nozzles are slit-shaped and extend crosswise to said traveling direction.  
   
   
       10 . A thermal treating apparatus as defined in  claim 9 , wherein said air blow nozzles are disposed in a zigzag manner.  
   
   
       11 . A thermal treating apparatus as defined in  claim 7 , wherein said hot air supply unit is disposed 3-300 mm distant from said coating layer.  
   
   
       12 . A thermal treating apparatus as defined in  claim 11 , wherein said at least one hot air supply unit comprises plural hot air supply units; 
 said at least one exhaust unit comprises plural exhaust units disposed alternately with said plural hot air supply units in said traveling direction.    
   
   
       13 . A thermal treating apparatus as defined in  claim 11 , further comprising a far infrared heater for applying heat energy to said coating layer in addition to said hot air from said hot air supply unit.  
   
   
       14 . A thermal treating apparatus as defined in  claim 13 , wherein said coating liquid includes liquid crystalline compound, and said coating layer is a liquid crystal layer of an optical compensatory sheet.  
   
   
       15 . A sheet producing apparatus for producing a sheet from web, comprising: 
 a coater for coating said web being traveled with coating liquid to form a coating layer;    at least one hot air supply unit for blowing said coating layer with hot air;    at least one exhaust unit, disposed upstream or downstream from said hot air supply unit in a traveling direction of said web, for sucking said hot air from said coating layer; and    a controller for adjusting a first flow speed at which said hot air is supplied by said hot air supply unit, and a second flow speed at which said hot air is sucked by said exhaust unit.