Patent Publication Number: US-2006000550-A1

Title: Apparatus for peeling release film

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates generally to apparatuses for manufacturing liquid crystal display devices, and more particularly to an apparatus for peeling release films off from polarization plates.  
      2. Description of the Prior Art  
      Manufacturing liquid crystal display devices comprises many processing steps. Among them, there is a process of gluing a polarization film onto a liquid crystal display panel (or liquid crystal cell). For conveniently gluing the polarization film onto the liquid crystal display element, a polarization plate comprising an adhesive polarization film and a release film is provided.  
      As shown in  FIG. 5 , a polarization plate  40  comprises an adhesive polarization film  41  and a release film  42 . The adhesive polarization film  41  comprises an adhesive surface  43  contacting the release film  42 , for gluing the polarization film  41  onto the liquid crystal display element.  
      In order to peel the release film  42  off from the polarization plate  40  in an automated manufacturing process, a release film peeling apparatus used in a polarization film gluing apparatus has been developed. Referring to  FIG. 6  and  FIG. 7 , a top elevation view and a side elevation view of a conventional release film peeling apparatus  1  are shown. The release film peeling apparatus  1  comprises a first roller  31 , a second roller  32 , a motion driver  10 , a rod  11 , a guiding track  12 , and two tapes  30   a  and  30   b.    
      As shown in  FIG. 7 , the first roller  31  rotates in a counterclockwise direction, and the rod  11  slides over the polarization plate  40  such that the tapes  30  are adhered onto the release film  42  of the polarization plate  40 . The second roller  32  then rotates in a clockwise direction, and collects the tapes  30  such that they peel the release film  42  off from the polarization film  41 . The motion driver  10  drives the rod  11  to move back and forth along the guiding track  12 , as indicated by the double-headed arrows. In order to peel the release film  42  off from the polarization plate  40 , the rod  11  first guides the tapes  30  from the right-hand side of the polarization plate  40  to the left-hand side of the polarization plate  40 , thereby applying the tapes  30  on the polarization plate  40 . Then, the rod  11  guides the tapes from the left-hand side of the polarization plate  40  to the right-hand side of the polarization plate  40 . Since the adhesion of the tapes  30  on the release film  42  is stronger than that of the release film  42  on the polarization film  41 , the release film  42  is consequently peeled off from the polarization film  41 .  
      However, when the rod  11  guides the tapes  30  to peel off the release film  42 , the tapes  30  may deviate from their normal working positions because of asymmetrical movement of other structures of the release film peeling apparatus  1  or because of external interference. When such deviation occurs, the process of peeling the release film  42  may fail, thereby disrupting the entire manufacturing process. Therefore, a manufacturing means that can overcome this problem is needed.  
     SUMMARY OF THE INVENTION  
      In light of the above, one objective of the present invention is to provide a release film peeling apparatus that can detect deviation of tapes thereof so as to prevent failure in the ongoing process of peeling off of release films.  
      In order to achieve the above and other objectives, an apparatus for peeling a release film off from a polarization film comprises: a winding mechanism for winding a tape that adheringly peels the release film off from the polarization film; a release film peeling mechanism comprising a guiding track and a peeling initiator, wherein the peeling initiator guides the tape in accordance with the winding mechanism and moves along the guiding track for peeling off the release film; and a detecting means comprising a mount and at least one detector, wherein the detector is installed on the mount for detecting deviation of the tape.  
      The detector of the present invention is preferably an optical detector, which comprises a light beam emitter and a light beam sensor. The light beam emitter emits a light beam aimed adjacent one side of the tape. If the tape deviates from its normal working position to the position aimed at by the detector, the light beam emitted from the light beam emitter is reflected by the tape, the detector detects the reflected light beam as a signal indicating a deviation of the tape, and a signal is sent to a control unit from the detector. The control unit then sends out a signal to a power supply of the apparatus to turn off the apparatus, and also sends out an alarm signal to alert relevant personnel of the occurrence of the deviation.  
      Other objects, advantages, and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  illustrates a top elevation of a release film peeling apparatus in accordance with a first embodiment of the present invention.  
       FIG. 2  illustrates a side elevation of the release film peeling apparatus of  FIG. 1 .  
       FIG. 3  schematically illustrates an enlarged, bottom elevation of a detector of the release film peeling apparatus of  FIG. 1 .  
       FIG. 4  schematically illustrates an enhanced release film peeling apparatus in accordance with a second embodiment of the present invention.  
       FIG. 5  illustrates a side elevation of a conventional polarization plate, showing a release film thereof partly peeled off from a polarization film thereof.  
       FIG. 6  illustrates a top elevation of a conventional release film peeling apparatus.  
       FIG. 7  illustrates a side elevation of the release film peeling apparatus of  FIG. 6 . 
    
    
     DETAILED DESCRIPTION OF THE PRESENT INVENTION  
      Hereinafter, the present invention is described in detail with reference to the accompanying drawings, wherein like reference numerals represent like elements.  
      Referring to  FIG. 1  and  FIG. 2 , a top elevation view and a side elevation view of a release film peeling apparatus  100  according to the first embodiment of the invention are shown. The release film peeling apparatus  100  comprises a first roller  131 , a second roller  132 , a motion driver  110 , a rod  111 , a guiding track  112 , a detecting means  120 , and two tapes  130 . The two tapes  130  are a first tape  130   a  and a second tape  130   b.  The tapes  130  adhere on a release film  142  of a polarization plate  140 . A strength of the adhesion is greater than that of an adhesion of the release film  142  on a polarization film  141  of the polarization plate  140 .  
      The detecting means  120  comprises a mount  122 , and a plurality of detectors  121  installed on the mount  122 . In the first embodiment, four detectors  121   a,    121   b,    121   c  and  121   d  are provided for detecting any deviations of the tapes  130 . In embodiments, even one detector  121  only may be sufficient for achieving the function of detecting any deviations of the tapes  130 . The detectors  121  are optical detectors. Alternatively, the detectors  121  can be any of various other types of detectors. As shown in  FIG. 3 , each detector  121  comprises a light beam emitter  123  and a light beam sensor  124 . The light beam emitter  124  emits either a visible light beam or an infrared light beam, depending on the particular requirements of a user. The light beam sensor  124  detects the corresponding visible light beam or infrared light beam.  
      In assembly and preparation for use of the release film peeling apparatus  100 , the motion driver  110  is attached on an end of the guiding track  112 , and the rod  111  is slidably connected to the guiding track  112 . The first roller  131  and the second roller  132  are rotatably fixed to a working station (not shown), and are substantially parallel to each other and kept apart a certain minimum distance. Opposite ends of each of the tapes  130   a,    130   b,  are wound around the first roller  131  and the second roller  132  respectively, such that middle portions of the tapes  130   a,    130   b  can be freely drawn out by the rod  111 . The detecting means  120  is disposed above the tapes  130   a,    130   b,  with the four detectors  121   a,    121   b,    121   c  and  121   d  corresponding to peripheries of the two tapes  130   a,    130   b.    
      In operation, the first roller  131  rotates in a counterclockwise direction, and the rod  111  slides over the polarization plate  140  so that the tapes  130  are adhered on the release film  142  of the polarization plate  140 . The second roller  132  then rotates in a clockwise direction, and collects the tapes  130  such that they peel the release film  142  off from the polarization film  141 . In this process, the first roller  131  and the second roller  132  rotate in opposite directions, and cooperate with the rod  111  to unwind and wind the tapes  130  such that the tapes  130  are maintained at a predetermined tension. The predetermined tension is less than a tension that may break the tapes  130 . Further, the predetermined tension is greater than a tension that may allow first portions of the tapes  130  (between the rod  111  and the first roller  131 ) to contact respective second portions of the tapes  130  (between the rod  111  and the second roller  132 ). In the first embodiment, the first roller  131  and the second roller  132  winding the first tape  130   a  and the second tape  130   b  form a winding mechanism.  
      The motion driver  110  drives the rod  111  to move back and forth along the guiding track  112 , as indicated by the double-headed arrows. In order to peel the release film  142  off from the polarization film  141 , the rod  111  first guides the tapes  130  from the right-hand side of the polarization plate  140  to the left-hand side of the polarization plate  40 , thereby applying the tapes  130  on the release film  142 . Then, the rod  111  guides the tapes  130  from the left-hand side of the polarization plate  140  to the right-hand side of the polarization plate  140 . Since the adhesion of the tapes  130  on the release film  142  is stronger than that of the release film  142  on the polarization film  141 , the release film  142  is consequently peeled off from the polarization film  141 . Therefore in the first embodiment, the motion driver  110 , the rod  111  and the guiding track  112  can be considered to form a release film peeling mechanism, wherein the motion driver  110  and the rod  111  form a peeling initiator.  
      The first detector  121   a  emits a light beam aimed adjacent one side of the first tape  130   a,  while the second detector  121   b  emits a light beam aimed adjacent the other side of the first tape  130   a.  If the first tape  130   a  deviates from its normal working position to the position aimed at by the first detector  121   a,  the light beam emitted from the light beam emitter  123  of the first detector  121   a  is reflected by the first tape  130   a,  and the first detector  121   a  detects the reflected light beam as a signal indicating a deviation of the first tape  130   a.  If the first tape  130   a  deviates from its normal working position to the position aimed at by the second detector  121   b,  the light beam emitted from the light beam emitter  123  of the second detector  121   b  is reflected by the first tape  130   a,  and the second detector  121   b  detects the reflected light beam as a signal indicating a deviation of the first tape  130   a.  Likewise, the third detector  121   c  emits a light beam aimed adjacent one side of the second tape  130   b,  while the fourth detector  121   d  emits a light beam aimed adjacent the other side of the second tape  130   b.  If the second tape  130   b  deviates from its normal working position to the position aimed at by the third detector  121   c,  the light beam emitted from the light beam emitter  123  of the third detector  121   c  is reflected by the second tape  130   b,  and the third detector  121   c  detects the reflected light beam as a signal indicating a deviation of the second tape  130   b.  If the second tape  130   b  deviates from its normal working position to the position aimed at by the fourth detector  121   d,  the light beam emitted from the light beam emitter  123  of the fourth detector  121   d  is reflected by the second tape  130   b,  and the fourth detector  121   b  detects the reflected light beam as a signal indicating a deviation of the second tape  130   b.    
      Although two tapes  130  are used in the release film peeling apparatus  100  of the first embodiment, in certain applications only one tape  130  may be sufficient for achieving the result of peeling off of the release film  142 . The above-described rotation directions of the first roller  131  and the second roller  132  are for illustrative purposes only, and no particular limitation is intended to apply to the rotation directions.  
      Referring to  FIG. 4 , an enhanced release film peeling apparatus  101  according to the second embodiment of the invention is schematically illustrated. The enhanced release film peeling apparatus  101  comprises the release film peeling apparatus  100 , a control unit  150 , and a power supply  160 .  
      In operation of the release film peeling apparatus  101 , once any deviation of the tapes  130  is detected by the corresponding light beam sensor  124 , the corresponding detector  121  sends out a deviation signal to the control unit  150 . The control unit  150  then processes the received signal and sends out a switching signal to the power supply  160 , which switches off the driving power to the release film peeling apparatus  100 . The control unit  150  also sends out a signal to an alarm device such as a loudspeaker (not shown), so as to alert relevant personnel of the occurrence of the tape deviation.  
      In summary, with the utilization of the detecting means  120  in the release film peeling apparatus  100 , any abnormal deviation of the tapes  130  can be timely detected. Further, with the aid of the control unit  150  in the enhanced release film peeling apparatus  101 , the deviation can be timely corrected. As a result, the ongoing process of peeling off of successive release films  142  can be carried on with maximum efficiency and at reduced cost.  
      Although the present invention has been described in detail in terms of the above embodiments, other embodiments may be practiced. A person having ordinary skill in the art may make modifications and/or alterations that are within the scope of the present invention or equivalent to the present invention. Therefore, the subject matter sought to be patented is that which is defined in the following claims and allowable equivalents thereof.