Abstract:
Disclosed herein is a vacuum/exhaust and getter tube that is capable of mitigating the difficulty of performing a tip-off process, which is caused by respectively separating an exhaust tube and a getter tube from holes. The vacuum/exhaust and getter tube includes a tube upper and lower ends of which are open, and a getter which is inserted into the tube.

Description:
[0001]    The present disclosure relates to subject matter contained in priority Korean Application No. 10-2005-0070072, filed on Jul. 30, 2005, which are herein expressly incorporated by reference in their entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a vacuum/exhaust and getter tube that is capable of mitigating the difficulty of performing a tip-off process, which is caused by respectively separating an exhaust tube and a getter tube from holes. 
         [0004]    2. Description of the Related Art 
         [0005]    Cold-Cathode Fluorescent Lamps (CCFLs) are mainly used as lamps for various illumination devices or displays. Such CCFLs are classified according to the location of electrodes, as either Internal Electrode Fluorescent Lamps (IEFLs), in which electrodes are installed inside sealed glass tubes containing discharge gas and gaseous mercury and fluorescent material is applied to the inside surfaces of the glass tubes, or External Electrode Fluorescent Lamp (EEFLs), in which electrodes are installed outside glass tubes and fluorescent material is formed on the inside surfaces of the glass tubes. 
         [0006]    When high-frequency Alternating Current (AC) signals are applied to the internal electrodes of an IEFL, an electric field is generated between the electrodes, therefore plasma discharge is generated. Electrons, which are generated during the discharge, excite mercury, and ultraviolet rays are generated. Thereafter, the ultraviolet rays excite fluorescent material and cause the transition of the fluorescent material, thus resulting in the generation of visible rays. 
         [0007]    In contrast, when high-frequency AC signals are applied to the external electrodes of an EEFL, plasma discharge is generated between positive electrodes inside a glass tube, electrons are generated, and mercury is excited by the electrons and causes fluorescent material to emit light. Such an EEFL has advantages in that the amount of heat is low and the EEFL is driven at high efficiency because wall charges are formed on the inner surface of a glass tube near electrodes by plasma discharge and plasma discharge is in turn generated using the wall charges, and a plurality of EEFLs can be driven using a single inverter because voltage drop is very small. 
         [0008]    Meanwhile, an LCD displays images by adjusting the transmissivity of liquid crystal cells in response to video signals. An active matrix LCD has an advantage in its ability to display moving images because switching elements are formed for respective liquid crystal cells. Thin Film Transistors (hereinafter referred to as “TFTs”) are chiefly used as the switching elements. 
         [0009]    An LDC is not a self-emissive device, therefore it requires a separate backlight unit. Conventional backlight units for LCDs are classified into edge light-type backlight units, each of which converts light, radiated from a lamp located at one end thereof, into surface light using a light guide plate, and radiates the surface light onto an LCD panel, and direct light-type backlight units, each of which radiates light onto an LCD panel using a plurality of lamps located under the LCD panel. 
         [0010]    Recently, research and development into Light source devices, which have light emission efficiency, luminance, and uniformity of luminance greater than those of existing edge light type backlight units or existing direct light type backlight units, is being actively conducted. 
         [0011]    Such an LIGHT SOURCE DEVICE, as shown in  FIG. 1 , includes a front glass substrate  11  provided with an exhaust hole  11   a  and a mercury injection hole  11   b,  a rear glass substrate  12  sealed to the front glass substrate  11  with partitions  14  and plasma discharge channels  19  interposed therebetween, a plurality of electrodes  13  formed on the rear glass substrate  12 , and fluorescent material  15  applied on the surfaces of the partitions  14  and the glass substrates  11  and  12  within the plasma discharge channels  19 . 
         [0012]    A vacuum/exhaust process for such an LIGHT SOURCE DEVICE is performed by attaching a vacuum/exhaust tube  16  to an exhaust hole  11   a  using a sealant and then exhausting air from the plasma discharge channels  28  to the outside through the vacuum/exhaust tube  16  using a vacuum pump (not shown). A discharge gas injection process is performed by injecting discharge gas, including inert gas, into the plasma discharge channels  19  through the vacuum/exhaust tube  16 . 
         [0013]    A mercury injection process for the LIGHT SOURCE DEVICE is performed by attaching a getter tube  17 , into which a getter  18  has been inserted, to the mercury injection hole  11   b  using a sealant, and activating the getter  18  in such a way as to place an inductor (not shown) near the getter tube  17  and apply induced current to the getter  18  in the getter tube  17  through the application of Alternating Current (AC) to the inductor, with the result that mercury is injected into the plasma discharge channels  19 . 
         [0014]    After the above-described vacuum/exhaust process, discharge gas injection process and mercury injection process have been completed, a tip-off process of separating the vacuum/exhaust tube  16  from the exhaust hole  11   a  and the getter tube  17  from the mercury injection hole  11   b  is performed, and, finally, a process of sealing the exhaust hole  11   a  and the mercury injection hole  11   b  is performed. 
         [0015]    Meanwhile, a conventional LIGHT SOURCE DEVICE manufacturing process has disadvantages in that the exhaust tube  16  and the getter tube  17  are respectively separated from the holes in the tip-off process, and in that the exhaust hole  11   a  and the mercury injection hole  11   b  must be sealed after the tip-off process. Furthermore, the conventional LIGHT SOURCE DEVICE has a problem in that the luminance around the exhaust hole  11   a  and the mercury injection hole  11   b  is lower than that in other effective light emission regions, therefore the uniformity of luminance is relatively low. 
       SUMMARY OF THE INVENTION 
       [0016]    Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a vacuum/exhaust and getter tube that is capable of simplifying a tip-off process for an LIGHT SOURCE DEVICE and improving the uniformity of luminance. 
         [0017]    In order to accomplish the above object, the present invention provides a vacuum/exhaust and getter tube, including a tube the upper and lower ends of which are open; and a getter which is inserted into the tube. 
         [0018]    The tube includes a first tube the upper and lower ends of which are open; a second tube into which the getter is inserted, and the upper and lower ends of which are open; and a first neck portion which is formed between the first and second tubes to be narrower than each of the first and second tubes, and which provides a passage between the first and second tubes. 
         [0019]    The vacuum/exhaust and getter tube further includes a second neck portion which is formed at the lower end of the second tube to be narrower than the second tube, and which provides a passage between the second tube and the plasma discharge channels of an LIGHT SOURCE DEVICE. 
         [0020]    Each of the first and second neck portions has an inner diameter smaller than the diameter of the getter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0022]      FIG. 1  is a sectional view showing a conventional LIGHT SOURCE DEVICE, a conventional vacuum/exhaust tube and a conventional getter tube; 
           [0023]      FIG. 2  is a sectional view showing an LIGHT SOURCE DEVICE and a vacuum/exhaust and getter tube according to an embodiment of the present invention; 
           [0024]      FIG. 3  is a partial cutaway perspective view showing the structure of the vacuum/exhaust and getter tube of  FIG. 2  in detail; 
           [0025]      FIG. 4  is a sectional view showing an LIGHT SOURCE DEVICE and a vacuum/exhaust and getter tube according to another embodiment of the present invention; and 
           [0026]      FIG. 5  is a partial cutaway perspective view showing the structure of the vacuum/exhaust and getter tube of  FIG. 4  in detail. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]    Reference now should be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components. 
         [0028]    With reference to  FIGS. 2 to 5 , preferred embodiments of the present invention are described below. 
         [0029]    Referring to  FIGS. 2 and 3 , an LIGHT SOURCE DEVICE according to an embodiment of the present invention includes a front glass substrate  21  provided with an exhaust/mercury injection hole  21   a,  a rear glass substrate  22  sealed to the front glass substrate  21  with partitions  24  and plasma discharge channels  28  disposed therebetween, a plurality of electrodes  23  formed on the rear glass substrate  22 , and fluorescent material  25  applied to the surfaces of the partitions  24  and the glass substrates  21  and  22  within the plasma discharge channels  28 . 
         [0030]    Holes (not shown) are formed through the partitions  24  to form a passage so that gas can move between the plasma discharge channels  28 . 
         [0031]    A vacuum/exhaust process for the LIGHT SOURCE DEVICE is performed by attaching a vacuum/exhaust and getter tube  26 , into which a getter  27  has been inserted, to the exhaust/mercury injection hole  21   a  using a sealant and then exhausting air from the plasma discharge channels  28  to the outside through the vacuum/exhaust and getter tube  26  using a vacuum pump. A discharge gas injection process is performed by injecting discharge gas, including inert gas, into the plasma discharge channels  28  through the vacuum/exhaust and getter tube  26 . Thereafter, mercury is injected to the plasma discharge channels  28  by activating the getter  27  in such a way as to place an inductor (not shown) near the vacuum/exhaust and getter tube  26  and apply induced current to the getter  27  in the vacuum/exhaust and getter tube  26  through the application of AC current to the inductor. 
         [0032]    After the vacuum/exhaust process, the discharge gas injection process and the mercury injection process have been completed using the vacuum/exhaust and getter tube  26 , as described above, a tip-off process of separating the vacuum/exhaust and getter tube  26  from the exhaust/mercury injection hole  21   a  is performed, and finally, a process of sealing the exhaust/mercury injection hole  21   a  is performed. 
         [0033]    As a result, in the process of manufacturing an LIGHT SOURCE DEVICE according to the present invention, only the single vacuum/exhaust and getter tube  26  is separated from the hole  21   a  in the tip-off process, therefore the tip-off process is simplified, and only the single hole  21   a  is formed through the substrate  11 , therefore luminance and the uniformity of luminance can be improved. 
         [0034]    The LIGHT SOURCE DEVICE according to the present invention can be used as a light source for a non-emissive device, such as a general illumination device or an LCD. 
         [0035]      FIG. 3  is a perspective view of the vacuum/exhaust and getter tube  26 . 
         [0036]    Referring to  FIGS. 2 and 3 , the vacuum/exhaust and getter tube  26  includes first and second glass tubes  26   a  and  26   c  connected to each other with a first neck portion  26   b  disposed therebetween, and a getter  27  inserted into the second glass tube  26   c.    
         [0037]    The first glass tube  26   a  is a cylindrical glass tube, the upper and lower ends of which are open, and functions to form a passage between the outside and the plasma discharge channels  28  in the vacuum/exhaust process and the discharge gas injection process. The lower end of the first glass tube  26   a  is formed to have an inner diameter smaller than the diameter of the getter  27 . 
         [0038]    The second glass tube  26   c  is a cylindrical glass tube which has an inner diameter greater than the diameter of the getter  27  and the upper and lower ends of which are open, and functions to form a passage between the outside and the plasma discharge channels  28  in the vacuum/exhaust process and the discharge gas injection process, and to form a passage through which mercury is injected from the getter  27  into the plasma discharge channels  28  at the time of activation of the getter  27 . Each of the upper and lower ends of the second glass tube  26   c  is formed to have an inner diameter smaller than the diameter of the getter  27 . 
         [0039]    The first neck portion  26   b  functions to connect the first and second glass tubes  26   a  and  26   c  to each other, to form a passage therebetween, and to confine the getter  27  within the second glass tube  26   c.  The first neck portion  26   b  includes the lower end of the first glass tube  26   a  and the upper end of the second glass tube  26   c,  each of which has an inner diameter smaller than the diameter of the getter  27 . 
         [0040]    The second neck portion  26   d  corresponds to the lower end of the second glass tube  26   c,  which has an inner diameter smaller than the diameter of the getter  27 , and functions to form a passage between the second glass tube  26   c  and the plasma discharge channels  28  via the exhaust/mercury injection hole  21   a,  and to confine the getter  27  within the second glass tube  26   c.  This second neck portion  26   d  is attached to the portion of the front glass substrate  21  near the exhaust/mercury injection hole  21   a  using a sealant. 
         [0041]    In  FIGS. 4 and 5  is shown a vacuum/exhaust and getter tube  36  according to another embodiment of the present invention. 
         [0042]    Referring to  FIGS. 4  and S, the vacuum/exhaust and getter tube  36  according to another embodiment of the present invention is different from the vacuum/exhaust and getter tube  26  shown in  FIGS. 2 and 3  in that the lower end and a side portion thereof, rather than the upper and lower ends thereof, are open. 
         [0043]    The side opening of the vacuum/exhaust and getter tube  36  is sealed after the air within the plasma discharge channels  28  has been exhausted to the outside, and the lower opening of the vacuum/exhaust and getter tube  36  is attached to a front glass substrate  21 , in which an exhaust/mercury injection hole  21   a  is formed, and functions as a passage through which air is exhausted to the outside and mercury is injected into plasma discharge channels  28 . 
         [0044]    The vacuum/exhaust and getter tube  36  includes first and second glass tubes  36   a  and  36   c  connected to each other with a first neck portion  36   b  disposed therebetween, and a getter  27  inserted into the second glass tube  36   c.  Here, the first and second glass tubes  36   a  and  36   c  are connected perpendicular to each other, so that a first neck portion  36   b  is formed on the side of the vacuum/exhaust and getter tube  36 . 
         [0045]    The first glass tube  36   a  is a cylindrical glass tube the front and rear ends of which are open, and functions to form a passage between the outside and the plasma discharge channels  28  in the vacuum/exhaust process and the discharge gas injection process. The rear end of the first glass tube  36   a  is formed to have an inner diameter smaller than the diameter of the getter  27 . 
         [0046]    The second glass tube  36   c  is a cylindrical glass tube which has an inner diameter greater than the diameter of the getter  27  and the side and lower end of which are open, and functions to form a passage between the outside and the plasma discharge channels  28  in the vacuum/exhaust process and the discharge gas injection process, and to form a passage through which mercury is injected from the getter  27  into the plasma discharge channels  28  at the time of activation of the getter  27 . Each of the side and lower end of the second glass tube  26   c  is formed to have an inner diameter smaller than the diameter of the getter  27 . 
         [0047]    The first neck portion  36   b  functions to connect the first and second glass tubes  36   a  and  36   c  to each other, to form a passage therebetween, and to confine the getter  27  within the second glass tube  36   c.  This first neck portion  36   b  includes the rear end of the first glass tube  36   a  and the side portion of the second glass tube  36   b,  each of which has an inner diameter smaller than the diameter of the getter  27 . 
         [0048]    Meanwhile, the second neck portion  36   d  is the same as the second neck portion  26   d  shown in  FIG. 3 . 
         [0049]    Although  FIGS. 2 to 5  show only the embodiments in which the exhaust hole, to which the getter tube is attached, is formed in the front side of the LIGHT SOURCE DEVICE, the exhaust hole, to which the getter tube is attached, may be formed in the rear or lateral side of the LIGHT SOURCE DEVICE, instead of the front side of the LIGHT SOURCE DEVICE. 
         [0050]    Meanwhile, although the above description illustrates embodiments in which the getter tube is attached to an LIGHT SOURCE DEVICE to be applied to an LCD, it will be apparent to developers having ordinary skill in the art that the getter tube according to the present invention can be applied to a process of manufacturing a Plasma Display Panel (PDP) in the same way without departing from the scope of the present invention. 
         [0051]    In the case where the vacuum/exhaust and getter tube, in which a vacuum/exhaust tube and a getter tube are integrated, according to the present invention, is employed, the number of passages in the glass substrate of the LIGHT SOURCE DEVICE, which are used for vacuum/exhaust and mercury injection, is reduced from two to one. Meanwhile, there is a problem in that luminance is reduced around vacuum/exhaust and mercury holes formed in a glass substrate compared to the other regions of the glass substrate. According to the present invention, the number of the holes can be reduced by half, therefore the overall luminance becomes relatively uniform. 
         [0052]    Furthermore, as described above, in an existing process of manufacturing an LIGHT SOURCE DEVICE, an existing exhaust tube and an existing getter tube must be respectively separated from holes in a tip-off process, whereas, when the vacuum/exhaust and getter tube according to the present invention is employed, only a single process of removing the vacuum/exhaust and getter tube is necessary. As a result, the complexity of processes can be reduced. 
         [0053]    As described above, the vacuum/exhaust and getter tube according to the present invention integrates an existing vacuum/exhaust tube and an existing getter tube into a single tube, thereby simplifying the tip-off process and improving the luminance of the LIGHT SOURCE DEVICE and the uniformity of the luminance. 
         [0054]    Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.