Abstract:
An automatic transfer apparatus for a liquid crystal display device comprising a mounting unit for placing a cassette in which a plurality of substrates are received, a moving unit disposed at a lower surface of the mounting unit and moving within a designated interval or section, and a sensing member mounted in the moving unit for sensing an obstacle, wherein the sensing member for sensing an obstacle at a bottom is disposed at the lower surface of the automatic transfer apparatus so as to enable a previous checking an existence of the obstacle, thereby preventing a structure of the automatic transfer apparatus from being damaged due to the obstacle.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an automatic transfer apparatus for a liquid crystal display (LCD) device and a method for sensing obstacle using the same, and particularly, to an automatic transfer apparatus for an LCD device which is capable of preventing a damage on a structure of an automatic transfer apparatus due to an obstacle by mounting a sensing member which is mounted at a bottom surface of the automatic transfer apparatus to sense the obstacle on the bottom, and by previously checking an existence of the obstacle. 
     2. Background of the Invention 
     Development of information society has gradually enhanced requirements for various types of display devices. Among various types of flat panel display devices such as liquid crystal displays (LCDs), plasma display panels (PDPs), electro luminescent displays (ELDs), field emission displays (FEDs), and the like LCDs are spotlighted the most to continue be developed as monitors for TV sets and desktop computers as well as monitors for notebook computers. 
     The LCD device may broadly be divided into LCD panels for displaying images and a driving unit for applying a driving signal to the LCD panels. 
     As shown in  FIG. 1 , a related art LCD panel includes first and second substrates  1  and  2  which are bonded to each other with a certain space therebetween, and a liquid crystal layer  3  injected between the first and second substrates  1  and  2 . 
     Here, the first substrate  1  (i.e., a thin film transistor (TFT) array substrate) includes a plurality of gate lines  4  arranged in one direction by a certain interval therebetween, a plurality of data lines  5  arranged by a certain interval therebetween in a direction perpendicular to each gate line  4 , a plurality of pixel electrodes P formed in a matrix shape at each pixel region defined at an intersection between the gate lines  4  and the data lines  5 , and a plurality of TFTs which are switched by a signal from the gate line  4  to transfer a signal from the data line  5  to each pixel electrode P. 
     Furthermore, the second substrate  2  (i.e., a color filter substrate) includes a black matrix layer  7  for preventing light from being transmitted to regions rather than the pixel regions, R, G and B color filter layers  8  for rendering color and a common electrode  9  for implementing images. Here, the common electrode  9  may be formed on the first substrate  1  in an LCD device employing a horizontal electric field mode. 
     The LCD device having such structure is fabricated by processes for fabricating a TFT array on the first substrate  1 , fabricating a color filter layer on the second substrate  2 , bonding the first and second substrates  1  and  2  to each other, injecting a liquid crystal between the bonded substrates  1  and  2  and sealing the liquid crystal, testing and repairing each LCD panel in which the liquid crystal has been injected, and mounting a back light or the like in each LCD panel with a good quality and mounting a driving circuit to fabricate a liquid crystal display module. 
     The substrates undergoes such various processes to completely be the LCD device. The substrates are transferred to devices which perform each process by use of an automatic transfer apparatus. 
     With reference to  FIGS. 2 and 3 , explanation will now be given for a related art automatic transfer apparatus used to transfer the substrates to the devices for performing each process upon fabricating an LCD device. 
       FIG. 2  is a schematic view showing a related art automatic transfer apparatus having a cassette. 
       FIG. 3  is a schematic view showing the related art automatic transfer apparatus having the cassette, which shows a case that there is an obstacle on a movement direction. 
     Referring to  FIG. 2 , a related art automatic transfer apparatus  10  includes a mounting unit  15  for placing a cassette  31  in which a plurality of substrates are received in order to perform each process, and a moving unit  11  disposed at a bottom of the mounting unit  15  and moving within a designated interval, namely, moving toward each processing device by use of rotational movement members  13 . A distance T 1  is a height between the outer bottom surface  41  and the lower portion of the moving unit  11 . The mounting unit  15  of the automatic transfer apparatus  10  has a robot arm  21  which is used to load the cassette  31  which is positioned at an input port (not shown) and an output port (not shown) of a stoker (not shown) directly on the mounting unit  15  or to unload the cassette  31  which has been loaded on the mounting unit  15  to the stoker. 
     In a state that the automatic transfer apparatus  10  is moved toward each processing device in order to perform each process, the cassette  31  which has been loaded on the mounting unit  15  by the robot arm  21  or the cassette which is placed at the input port or output port is moved to each processing device or to the stoker. 
     However, as shown in  FIG. 3 , it is impossible for the automatic transfer apparatus  10  according to the related art to sense an obstacle  51  on the bottom out of the range in which a front of the obstacle  51  can be sensed. Here, T 2  is a thickness of the obstacle  51 . 
     Therefore, impurities come into the bottom of the automatic transfer apparatus  10 , which causes interference with a lower structure of the automatic transfer apparatus  10 , resulting in problems in devices. That is, when an obstacle which is not sensed at a bottom of a movement detecting sensor or the moving unit is sucked into the bottom of the automatic transfer apparatus, damages may occur on the bottom structure of the automatic transfer apparatus. 
     SUMMARY OF THE INVENTION 
     Therefore, an object of the present invention is to provide an automatic transfer apparatus for a liquid crystal display (LCD) device and a method for sensing obstacle using the same capable of preventing a damage on a structure of an automatic transfer apparatus by mounting a device for sensing an obstacle on a bottom of the automatic transfer apparatus. 
     To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided an automatic transfer apparatus for a liquid crystal display device comprising: a mounting unit; a moving unit disposed at the mounting unit; a sensing member disposed at the moving unit for sensing an obstacle; and an alarm signal unit for generating alarm signal. 
     To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provide d a method for sensing obstacle using an automatic transfer apparatus for a liquid crystal display device comprising: providing a mounting unit; providing a moving unit disposed at the mounting unit; disposing a sensing member at the moving unit for sensing an obstacle; and disposing an alarm signal unit to generate alarm signal. 
     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. 
       In the drawings: 
         FIG. 1  is an exploded perspective view showing a part of a related art LCD panel; 
         FIG. 2  is a schematic view showing a related art automatic transfer apparatus in which a cassette is mounted; 
         FIG. 3  is a schematic view showing the related art automatic transfer apparatus in which the cassette is mounted, which shows a case that there exists an obstacle on a movement direction; 
         FIG. 4  is a schematic view showing an automatic transfer apparatus for an LCD device according to an one embodiment of the present invention; 
         FIG. 5  is a lateral view showing the automatic transfer apparatus according to the one embodiment of the present invention, which shows an obstacle sensing member. 
         FIG. 6  is a schematic view showing an obstacle sensing member mounted at a bottom portion of the automatic transfer apparatus according to the one embodiment of the present invention; and 
         FIG. 7  is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to the one embodiment of the present invention. 
         FIG. 8  is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to an another embodiment of the present invention. 
         FIG. 9  is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to further another embodiment of the present invention. 
         FIG. 10  is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to further another embodiment of the present invention. 
         FIG. 11  is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to further another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Description will now be given in detail of the present invention, with reference to the accompanying drawings. 
     Hereinafter, an automatic transfer apparatus for an LCD device according to the present invention will be explained in detail with reference to the attached drawings. 
       FIG. 4  is a schematic view showing an automatic transfer apparatus for an LCD device according to an one embodiment of the present invention, and  FIG. 5  is a lateral view of the automatic transfer apparatus according to the one embodiment of the present invention, which shows an obstacle sensing member. 
       FIG. 6  is a schematic view showing an obstacle sensing member at a bottom of the automatic transfer apparatus according to the one embodiment of the present invention. 
       FIG. 7  is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom of the automatic transfer apparatus according to the one embodiment of the present invention. 
     As shown in  FIGS. 4 and 5 , an automatic transfer apparatus  100  according to the present invention includes a mounting unit  115  for placing a cassette  141  in which a plurality of substrates are received in order to perform each process, and a moving unit  111  disposed at a lower portion of the mounting unit  115  and moving within a designated interval (section), namely, toward each processing device, by rotational movement members  113 . 
     Furthermore, the mounting unit  115  of the automatic transfer apparatus  100  is provided with a robot arm  131 , which is used to load the cassette  141  placed at an input port (not shown) or an output port (not shown) of a stoker (not shown) to the mounting unit  115  or to unload the cassette  141  loaded on the mounting unit  115  to the stoker (not shown). 
     In a state that the automatic transfer apparatus  100  is moved toward each processing device by virtue of the movement of the automatic transfer apparatus  100  in order to perform each process, the cassette  141  which has been loaded on the mounting unit  115  by the robot arm  131  or the cassette which is placed at the input port or output port is moved to each processing device or the stoker. 
     A sensing member is provided within the moving unit  111  of the automatic transfer apparatus  100 . The sensing member includes two tape sensors  121  and  123  and an obstacle sensing bar  125 . The one tape sensor  123  of the two tape sensors  121  and  123  is coupled to the obstacle sensing bar  125 . One end of the obstacle sensing bar  125  is protruded downwardly to outer bottom surface  151  by a predetermined distance T 3 . The distance T 3  is a height between the outer bottom surface  151  and the end portion of the obstacle sensing bar  125 . Further, the automatic transfer apparatus  100  includes an alarm signal unit (not shown) for generating alarm signal when the obstacle is sensed by the sensing member. 
     As shown in  FIGS. 5 ,  6  and  7 , the obstacle sensing bar  125  is protruded enough to sense an obstacle  161  having a thickness T 2  smaller than a height T 1  between the moving unit  111  of the automatic transfer apparatus  100  and the outer bottom surface  151 . The obstacle sensing bar  125  is protruded downwardly to outer bottom surface  151 . And the obstacle sensing bar  125  maybe incline in a forward or backward direction. The obstacle sensing bar  125  is configured to be pushed back when it is contacted with the obstacle  161 . When the obstacle sensing bar  125  is moved by being pushed back by the obstacle  161 , the tape sensor  123  coupled to the obstacle sensing bar  125  is simultaneously moved in a direction opposite to that of the obstacle sensing bar  125 , to be in contact with the other tape sensor  121  corresponding thereto. 
     Hence, as shown in  FIG. 7 , when the automatic transfer apparatus  100  is moved forwardly, if the obstacle  161  placed at the front area of the automatic transfer apparatus  100  is in contact with the obstacle sensing bar  125 , the obstacle sensing bar  125  is pushed back by the obstacle  161 . Then the tape sensor  123  coupled to the obstacle sensing bar  125  is moved in the opposite direction to that of the obstacle sensing bar  125  to be in contact with the other tape sensor  121 . The tape sensors  121  and  123  which have been contacted to each other start to be operated, thereby giving the automatic transfer apparatus  100  to a pause and operating an alarm by the alarm signal unit (not shown). 
     Afterwards, an operator removes the obstacle  161  sensed at the bottom of the automatic transfer apparatus  100  to continue to perform the operation. 
     Meanwhile, another embodiments of the present invention is described as follows. 
       FIG. 8  is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to an another embodiment of the present invention. 
       FIG. 9  is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to further another embodiment of the present invention. 
       FIG. 10  is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to further another embodiment of the present invention. 
       FIG. 11  is a schematic view showing an operational state of the obstacle sensing member mounted at the bottom portion of the automatic transfer apparatus according to further another embodiment of the present invention. 
     As shown in  FIG. 8 , a sensing member according to an another embodiment of the present invention includes two tape sensors  221   a  and  221   b  spaced apart from each other and an obstacle sensing bar  225  coupled to a tape sensor portion  223 . Accordingly, the tape sensor portion  223  coupled to one of two tape sensors  221   a  and  221   b.    
     Accordingly, one of the tape sensors  221   a  and  221   b  and the sensor portion  223  which have been contacted to each other start to be operated, thereby giving the automatic transfer apparatus to a pause and operating an alarm by the alarm signal unit (not shown). 
     Afterwards, an operator removes the obstacle  261  sensed at the bottom of the automatic transfer apparatus to continue to perform the operation. 
     As shown in  FIG. 9 , a sensing member according to further another embodiment of the present invention includes tape sensors  321  and  323  is in contact with each other and an obstacle sensing bar  325  coupled to a tape sensor  323 . Accordingly, when the obstacle sensing bar  325  is pushed back by the obstacle  361 , the tape sensor  323  is not contacted with the tape sensor  321 . 
     Accordingly, the tape sensors  321  and  323  have been not contacted to each other start to be operated, thereby giving the automatic transfer apparatus to a pause and operating an alarm by the alarm signal unit (not shown). 
     Afterwards, an operator removes the obstacle  361  sensed at the bottom of the automatic transfer apparatus to continue to perform the operation. 
     As shown in  FIG. 10 , a sensing member according to further another embodiment of the present invention includes a tape sensor  421 , and a obstacle sensing bar  425  spaced apart from the tape sensor  421 . Further, the obstacle sensing bar  425  includes another tape sensor portion  425   a  which is in contact with the tape sensor  421 . The obstacle sensing bar  425  and the another tape sensor  425   a  comprise a single body. 
     Accordingly, the tape sensors  421  and  425   a  have been contacted to each other start to be operated, thereby giving the automatic transfer apparatus to a pause and operating an alarm by the alarm signal unit (not shown). 
     Afterwards, an operator removes the obstacle  461  sensed at the bottom of the automatic transfer apparatus to continue to perform the operation. 
     As shown in  FIG. 11 , a sensing member according to further another embodiment of the present invention includes a obstacle sensing bar  525 . The obstacle sensing bar  525  has a sensor function for sensing the obstacle. 
     Accordingly, when the obstacle sensing bar  525  senses the obstacle  561 , thereby giving the automatic transfer apparatus to a pause and operating an alarm by the alarm signal unit (not shown). 
     Afterwards, an operator removes the obstacle  561  sensed at the bottom of the automatic transfer apparatus to continue to perform the operation. 
     As aforementioned, several effect can be expected by use of the automatic transfer apparatus for the LCD device according to the present invention. 
     Regarding the automatic transfer apparatus for the LCD device according to the present invention, the sensing bar capable of sensing the obstacle is mounted at the automatic transfer apparatus. Accordingly, the sensing bar can be used to easily sense and remove the obstacle while moving the automatic transfer apparatus, whereby such small obstacles which have not been detected can be sensed to accordingly be possible to protect the lower structure of the automatic transfer apparatus from being damaged due to the small obstacles. 
     Hence, upon using the automatic transfer apparatus according to the present invention, the obstacles can previously be detected to make the automatic transfer apparatus pause, thereby ensuring high stability of the automatic transfer apparatus. 
     As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.