Patent Publication Number: US-2013231231-A1

Title: Roller, apparatus and method for manufacturing same

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a roller, an apparatus and a method for manufacturing the roller. 
     2. Description of Related Art 
     Optical films define a number of micro structures. One method for forming the micro structures is a roll forming process using a metal roller. A circumference of the metal roller has impression patterns coupled with the micro structures. The impression pattern is formed by a laser knife. However, the roller of the roll forming process has a relatively low forming efficiency, and has a relatively high cost. 
     Therefore, it is desirable to provide a roller, an apparatus and a method for manufacturing the roller that can overcome the above-mentioned limitations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the embodiments should be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is a schematic view of a roller, according to a first exemplary embodiment. 
         FIG. 2  is a schematic view of an apparatus for manufacturing a roller, according to a second exemplary embodiment. 
         FIG. 3  is a flow chart of a method for manufacturing a roller, according to a third exemplary embodiment. 
         FIG. 4  is a schematic view of an apparatus for manufacturing a roller, according to a fourth exemplary embodiment. 
         FIG. 5  is a flow chart of a method for manufacturing a roller, according to a fifth exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a first exemplary embodiment of a roller  100  is used for manufacturing an optical film (not shown), and includes a cylindrical main body  31  and a seamless ring-shaped resin film  33  coated on a circumferential surface  301  of the main body  31 . 
     The main body  31  is made of stainless steel or other metals. The circumferential surface  301  has a number of teeth  302  to increase the adhesive potential of the resin film  33  thereon. In the first embodiment, the teeth  302  are the same as each other and are evenly distributed on the circumferential surface  301  making the main body  31  to be gear-shaped. Each of the teeth  302  is substantially triangle-shaped. A highest point of each teeth  302  is about 1 centimeter (cm) to 2 cm in height with respect to the circumferential surface  301 . The main body  31  defines a fixing hole  310  at the center thereof. In other embodiments, the fixing hole  310  can be omitted. 
     The resin film  33  is made of polymer resin having the molecular chain with fluorine element, such as ethylene tetrafluoroethylene (ETFE) or poly tetrafluoroethylene (PTFE). Therefore, the optical films are easily separated from the resin film  20 , and the quality of the optical films can be greatly improved. 
     The resin film  33  has a cylindrical-shaped rolling surface  330  opposite to the main body  31 , and defines a number of impression patterns  35  coupled with the micro structures of optical films. In the first embodiment, the impression patterns  35  are micro-grooves uniformly distributed on the rolling surface  330 . The thickness of the resin film  33  between the rolling surface  330  and the circumferential surface  301  is about 1.5 cm to about 2.5 cm. 
     Referring to  FIG. 2 , a second exemplary embodiment of an apparatus  200  for manufacturing the roller  100  includes a heating device  20 , a molding device  40 , and a processing device  60 . 
     The heating device  20  melts a polymer resin  10  at a first predetermined temperature. The polymer resin  10  is made of polymer resin having the molecular chain with fluorine element. In the second embodiment, the polymer resin  10  is made of PTFE, and the first predetermined temperature is about 340 Celsius degrees (° C.). 
     The molding device  40  molds a preprocessed resin film  33   a  on the circumstance surface  301  to form a preprocessed roller  30   a . The molding device  40  has two molding sheets  401  contacting with each other. The two molding sheets  401  cooperatively define a cylindrical molding cavity  41 . The molding device  40  further has an injection port  42  communicating with the molding cavity  41  and a rotating element  402  received in the molding cavity  41 . The main body  31  is received in the molding cavity  41  and can be driven by the rotating element  402  to rotate. In this embodiment, the rotating element  402  is a rotating shaft fit with and extending through the fixing hole  310 . 
     When the main body  31  rotates, the melted polymer resin  10  is poured into the molding cavity  41  through the injection port  42  until the molding cavity  41  is filled with the melted polymer resin  10 . When the melted polymer resin  10  is cooled to be half-solid or solid, a preprocessed resin film  33   a  coated on the main body  31  and the preprocessed roller  30   a  is obtained. Then the two molding sheets  401  are separated to take out the preprocessed roller  30   a  from the molding cavity  41 . In the second embodiment, the injection port  42  is defined on one of the two molding sheets  401 . 
     The processing device  60  forms the impression patterns  35  on the preprocessed resin film  33   a  to obtain the roller  30 . The processing device  60  includes a molding plate  601  and a driving element  604 . The molding plate  601  has a plane-shaped molding surface  602  evenly distributing a number of molding patterns  603 . In the second embodiment, the molding patterns  603  are micro-protrusions. The driving element  604  is used for driving the preprocessed roller  30   a  to roll on the molding surface  602  to form the impression patterns  35  on the processed resin film  33   a . In this embodiment, the driving element  604  is a rotating shaft fit with and extending through the fixing hole  310 . 
     In other embodiments, if the melted polymer resin  10  is cooled to be solid before being removed from the molding cavity  41 , the solid polymer resin  10  can be heated again to be half-solid, and thus the impression patterns  35  can be easily formed. 
     Also referring to  FIG. 3 , a third exemplary embodiment of a method for manufacturing the roller  100  using the apparatus  200  includes the following steps. 
     In step S 1 , the polymer resin  10  is provided, and is heated to be melted at a first predetermined temperature by the heating device  20 . In the third embodiment, the polymer resin  10  is made of PTFE, and the first predetermined temperature is about 340° C. 
     In step S 2 , the cylindrical main body  31  is provided, and is sandblasted to be rough to enforce the adhesive potential of the melted polymer resin  10  thereon. 
     In step S 3 , the main body  31  is placed in the molding cavity  41 . 
     In step S 4 , the main body  31  is driven to be rotate, and the melted polymer resin  10  is poured into the molding cavity  41  through the injection port  42  until the molding cavity  41  is filled. 
     In step S 5 , the melted polymer resin  10  is cooled to obtain the preprocessed roller  30   a . And the preprocessed roller  30   a  includes the main body  31  and the preprocessed film  33   a . The preprocessed film  33   a  has a preprocessed rolling surface  330   a  opposite to the main body  31 . 
     In step S 6 , the preprocessed roller  30   a  is taken out from the molding cavity  41 . 
     In step S 7 , the preprocessed rolling surface  330   a  is polished. 
     In step S 8 , the preprocessed resin film  33   a  is heated to be half-melted at a second predetermined temperature (such as 250° C.˜260° C.). 
     In step S 9 , the molding plate  601  having a plane-shaped molding surface  602  with a number of molding patterns  603  is provided, and the preprocessed roller  30   a  is driven to roll on the molding surface  602 , and thus to form a number of impression patterns  35  on the preprocessed resin film  33  to obtain the roller  30 . 
     Referring to  FIG. 4 , an apparatus  400  for manufacturing the roller  100  according to a fourth exemplary embodiment is shown. The difference between the apparatus  400  and the apparatus  200  is that the processing device  460  is a laser device, and includes a driving element  450 , an optical guiding system  71 , and a laser emitter  73 . The preprocessed roller  30   a  is positioned on the driving element  450 , and can be rotated by the driving element  450 . In this embodiment, the driving element  450  is a rotating shaft fit with and extending through the fixing hole  310 . The laser emitter  73  is used for emitting laser beams  731 . The optical guiding system  71  guides the laser beams  731  to the processed resin film  33   a , and includes a reflector  711  and a converging lens  713 . The reflector  711  reflects the laser beams  731  to the converging lens  713 . The converging lens  713  is aligned with the processed resin film  33   a  and converges the laser beams  731  to the processed resin film  33   a.    
     Also referring to  FIG. 5 , a method for manufacturing the roller  30  according to a fifth exemplary embodiment is shown, and includes the following steps. 
     The steps S 11 -S 18  are substantially the same as the steps S 1 -S 8  respectively. 
     The step S 19  includes the following sub-steps: the laser device  460  emits laser beams to the preprocessed resin film  33   a ; the laser device  460  is turned off; the preprocessed roller  30   a  is rotated a predetermined angle; and the laser device  460  is turned on and emits the laser beams to the preprocessed resin film  33   a  again. The above steps are repeated until the molding patterns  35  are formed on the preprocessed resin film  33   a , and thus the roller  30  is obtained. 
     By employing the apparatus and the method, the seamless ring-shaped preprocessed resin film  33   a  can be directly formed on the circumferential surface  301  of the main body  31  using the molding device, and then the impression patterns  35  can be directly formed on the preprocessed resin film  33   a  to from the resin film  33 , and the roller is thus obtained. Therefore, the manufacturing efficiency will be improved. 
     The above particular embodiments are shown and described by way of illustration only. The principles and the features of the present disclosure may be employed in various and numerous embodiments thereof without departing from the scope of the disclosure as claimed. The above-described embodiments illustrate the scope of the disclosure but do not restrict the scope of the disclosure.