Patent Publication Number: US-2012040036-A1

Title: Film producing system

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a film producing system, and particularly, to an optical film producing system. 
     2. Description of Related Art 
     Many optical films, such as brightness enhancement films (BEF), typically include a base layer and a micro-structured layer formed on a surface of the base layer. The micro-structure-layer enhances the brightness of the emitted light. 
     Currently, the optical film is produced by a roll-to-roll manner. In detail, a glue layer is dispensed on a surface of a base layer; the base layer with the glue layer passes through a space between two rollers. One of the rollers includes a micro-structured pattern formed on the surface. The two rollers apply pressure on the base layer with the glue layer, and then the micro-structure pattern is printed on the surface of the glue layer. And then, the base layer with the glue layer is transported to a light curing device for curing the glue layer. However, it is difficult to manufacture the roller with micro-structured pattern, so the cost of the roller is increased, and thus the cost of the optical film increases as well. 
     What is needed therefore is film producing system addressing the above-mentioned problems. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The components of the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments of the film producing system. Moreover, in the drawings, like reference numerals designate corresponding parts throughout several views. 
         FIG. 1  is a schematic view of a film producing system according to an exemplary embodiment of the present disclosure. 
         FIG. 2  is an isometric view of the pressing block of the film producing system of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a film producing system  100 , according to an exemplary embodiment, is shown. The film producing system  100  includes a glue dispenser  10 , a conveyor  20 , a compression molding device  30 , a light curing device  40 , and a flexible base  50 . 
     The glue dispenser  10  includes a container  11  and a dispensing nozzle  12  connected to the container  11 . The container  11  receives glue  200  therein. The nozzle  12  is in communication with the container  11  and dispenses the glue  200  onto the surface of the flexible base  50 . In this embodiment, the glue  200  is ultraviolet (UV) curable glue. 
     The conveyor  20  transports the flexible base  50  to reach the glue dispenser  10 , the compression molding device  30  and the light curing device  40 . The conveyor  20  includes a first roller  21 , a second roller  22  and a third roller  23 . The second roller  22  is between the first roller  21  and the third roller  23  and is spaced a predetermined distance from the first roller  21  and the third roller  23 . The glue dispenser  10  is positioned adjacent the first roller  21 , and the light curing device  40  is positioned adjacent to the third roller  23 . The flexible base  50  passes through in sequence the first roller  21 , the second roller  22  and the third roller  23 . In this embodiment, the first roller  21  and the second roller  22  are located on two opposite sides of the flexible base  50 , and the second roller  22  and the third roller  23  are located on a common side of the flexible base  50 . In other embodiments, the first roller  21 , the second roller  22 , and the third roller  23  can be on a common side of the flexible base  50 . 
     The first roller  21  and the second roller  22  are vertically aligned with each other, thus the flexible base  50  having a vertically oriented portion located between the first roller  21  and the second roller  22 . The vertical distance between the first roller  21  and the second roller  22  can be adjusted. The second roller  22  and third roller  23  are spaced a horizontal predetermined distance from each other. 
     The compression molding device  30  includes pressing roller  31  and a pressing block  32  spaced a predetermined distance from the pressing roller  31 . The pressing roller  31  and the pressing block  32  are correspondingly positioned at two opposite sides of the flexible base  50 . The pressing roller  31  and the pressing block  32  press the flexible base  50  with the glue  200  therebetween. Referring to  FIG. 2 , the pressing block  32  is substantially cuboid. A micro-structure pattern  321  is formed on a surface of the pressing block  32  opposite to the pressing roller  31 . In this embodiment, the micro-structure pattern  321  is comprised of a number of parallel grooves  321   a . A lengthwise direction of each of the grooves is substantially parallel to the movement direction A of the flexible base  50 . 
     The light curing device  40  solidifies the glue on the flexible base  50 . In this embodiment, the light curing device  40  is an ultraviolet radiation source. 
     The flexible base  50  carries the glue  200 . In this embodiment, the flexible base  50  is a thin film made from polyethylene terephthalate (PET). 
     The film producing system  100  produces optical film. In use, the glue  200  is dispensed in a gap between the first roller  21  and the flexible base  50 . In this embodiment, the glue dispenser  10  continuously dispenses glue  200  in the gap to keep a substantial amount of glue in the gap  200 , thus the glue  200  can be uniformly dispensed on the flexible base  50 . The first roller  21 , the second roller  22 , and the third roller  23  are rotated at a predetermined speed for transporting the flexible base  50 . The glue  200  can be automatically dispensed on a surface of the flexible base  50  when the flexible base  50  is transported from the first roller  21  to the second roller  22 , and the glue  200  can be further uniformly dispensed on the surface of the flexible base  50  by gravity. The glue  200  is molded to a predetermined shape under the pressure of the compression molding device  30  when the flexible base  50  is transported through the compression molding device  30 . The micro-structure pattern  321  prints a similar micro-structure pattern (not labeled) on the surface of the glue  200  during the process of pressing the flexible base  50 . The glue  200  with the printed micro-structure pattern is solidified by the light curing device  40  when the flexible base  50  is transported to the light curing device  40 . Thereby, a micro-structure layer  201  is formed. 
     The viscosity of the glue  200  and the velocity of the flexible base  50  can be adjusted to ensure a proper dispensing thickness and the uniformity of glue  200  on the flexible base  50 , and a certain deformation resistance of the glue  200  after molding. In this embodiment, the viscosity of the glue  200  is at a range of about 0.2-1.5 Pa·s, the velocity of the flexible base  50  is at a range of about 10-20 meters/min. 
     In other embodiments, the first roller  21  and second roller  22  also can be spaced a horizontal distance from each other, thus the flexible base  50  between the first roller  21  and the second roller  22  is tilted at an angle relative to the vertical direction, and thus the requirement of the viscosity of the glue  200  can be reduced. In addition, the molded glue  200  should be solidified immediately to avoid the deformation of the glue  200  by gravity, at the same time the intensity of the ultraviolet radiation can be increased for enhancing the solidifying speed of the glue  200 . 
     The micro-structure layer  201  and the flexible base  50  can cooperatively form an optical film, or the micro-structure layer  201  itself can form an optical film after being separated from the flexible base  50 . 
     It is easy and inexpensive to manufacture the pressing block  32 , therefore, the cost of the film producing system  100  and the optical film produced by the film producing system  100  is reduced. 
     It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the disclosure.