Abstract:
A liquid crystal display (LCD) cell for an LCD device is disclosed that can be manufactured under easy rework processing for reduced cost. The LCD cell comprises a first transparent substrate; a second transparent substrate; and a sealing member. The sealing member is sandwiched between and fixedly binds the first and second transparent substrates in a structural alignment for image displaying operation of the LCD cell. The sealing member forms a perimeter encircling a display area of the LCD cell and having a discharge port at a location on the perimeter thereof. The perimeter encloses an optimized amount of liquid crystal obtained after the excessive liquid crystal trapped within the perimeter during the manufacture of the LCD cell is discharged out of the LCD cell through the discharge port. The perimeter sealedly encloses the optimized amount of liquid crystal therein after the discharge port is plugged for defect-free implementation of the image displaying operation.

Description:
BACKGROUND  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates in general to liquid crystal displays (LCD) and, in particular, to an LCD cell and the corresponding method of manufacturing thereof.  
         [0003]     2. Technical Background  
         [0004]     A typical LCD device is made up of two primary optical subassemblies: an LCD cell and a back-light module (BLM). BLM provides basic display light illumination for the display system while manipulation of birefringence of liquid crystal molecules in the LCD cell controls the light transmittance across the cell under different intensities and colors for each of the display pixels.  
         [0005]     An LCD cell is basically a component that provides a liquid crystal-containing space between two transparent substrates. A sealing material is used to enclose the thin rectangular liquid crystal-containing space corresponding to the display area of the LCD device and also serves to secure the substrates relative to each other. The manufacture of an LCD cell involves the application of the sealant along predefined rectangular path around the display area utilizing a small-caliber dispenser nozzle. The sealant is subsequently hardened in a curing process in which cross-linking results in the polymerization of the sealing material.  
         [0006]     One of the popular LCD cell manufacturing processes involves the filling of liquid crystal into the containing space in a vacuum-induced injection scheme. Such a process requires leaving a small opening at a selected location of the rectangular enclosing sealant. Normally the opening is shaped to allow for guided injection of liquid crystal into the containing space. Protrusions in a shaped opening frequently result in the accumulation of liquid crystal residue around themselves after liquid crystal is filled into the containing space via the opening, which is subsequently sealed such as by a resin-based material. Liquid crystal droplets outside of their intended containing space constitute problems to the LCD cell manufacturing. They constitute substantial contaminants and should be avoided. Also, such residues outside of the liquid crystal-containing space represent the waste of expensive material.  
         [0007]     One method capable of reducing LCD cell production costs via avoidance of liquid crystal residue wastes is related to the one-drop filling (ODF) of liquid crystal into its intended containing space. An ODF scheme involves preparing a rectangular sealant enclosure over the surface of one of the transparent substrates, placing sufficient droplets of liquid crystal over the surface of either one of the two substrates, and aligning and securing the two together in a sealed manner.  
         [0008]     Predetermined amount of liquid crystal material to be delivered in the droplets assist to reduce the waste of liquid crystal. The filling of liquid crystal into the containing space is also much faster than achievable in the vacuum-induced injection scheme described above. The reduction in both the material amount and the processing time results in significantly reduced manufacturing costs.  
         [0009]     However, capacity of the liquid crystal-containing space between the two transparent substrates alters due to various factors including, for example, slight twisting of either or both of the substrates. If the amount of liquid crystal delivered by the drops is insufficient, the containing space becomes correspondingly larger than it should be, air bubbles may form in the cell. On the other hand, if the containing space is relatively smaller than for the delivered liquid crystal droplets, the amount of the liquid crystal material becomes excessive, gravity mura may easily arise in the displace area of the cell. Regardless of whether it is excessive or insufficient liquid crystal in the containing space, an LCD cell is discarded as defective. Conventional ODF schemes allow no room for repair of these defective LCD cells. They are simply thrown away and wasted.  
       SUMMARY OF THE INVENTION  
       [0010]     There is therefore the need for an LCD cell and its corresponding method that can be processed in a manufacturing operation allowing for rework for enclosing an optimized amount of liquid crystal in the cell for defect-free display operation.  
         [0011]     The present invention thus provides a liquid crystal display cell for a liquid crystal display device comprising: a first transparent substrate; a second transparent substrate; and a sealing member, wherein said sealing member being sandwiched between and fixedly binding said first and second transparent substrates in a structural alignment for image displaying operation of said liquid crystal display cell; and said sealing member forming a perimeter encircling a display area of said liquid crystal display cell and having a discharge port at a location on said perimeter; said perimeter enclosing an optimized amount of liquid crystal obtained after the excessive liquid crystal trapped within said perimeter during the manufacture of said liquid crystal display cell is discharged out of said liquid crystal display cell through said discharge port; and said perimeter sealedly enclosing said optimized amount of liquid crystal therein after said discharge port is plugged for defect-free implementation of said image displaying operation.  
         [0012]     The present invention also provides a liquid crystal display cell for a liquid crystal display device comprising: a first transparent substrate; a second transparent substrate; and a sealing member, wherein said sealing member being sandwiched between and fixedly binding said first and second transparent substrates in a structural alignment for image displaying operation of said liquid crystal display cell; and said sealing member forming a perimeter encircling a display area of said liquid crystal display cell and having an array of a plurality of storage chambers formed along a location on said perimeter; said perimeter enclosing an optimized amount of liquid crystal obtained after the excessive liquid crystal trapped within said perimeter during the manufacture of said liquid crystal display cell is discharged into at least one of said plurality of storage chambers through openings broken between the containing space of said perimeter and the storage space of each of said at least one storage chambers; and said perimeter sealedly enclosing said optimized amount of liquid crystal therein after said discharge for defect-free implementation of said image displaying operation.  
         [0013]     The present invention further provides a method of manufacturing a liquid crystal display cell for a liquid crystal display device comprising the steps of: a) deploying a sealing member on a first substrate; said sealing member forming a perimeter encircling a display area of said liquid crystal display cell; b) delivering at least one drop of liquid crystal on either one of said first substrate and a second substrate; c) assembling said first substrate and said second substrate wherein said first and second substrates sandwiching said sealing member and are aligned for image displaying operation of said liquid crystal display cell; d) breaking a discharge port on said perimeter; e) discharging any excessive liquid crystal trapped within said perimeter out of said liquid crystal display cell through said discharge port; and e) plugging said discharge port of said sealing member thereby obtaining an optimized amount of liquid crystal enclosed in said perimeter for defect-free implementation of said image displaying operation.  
         [0014]     The present invention further provides a method of rework manufacturing a liquid crystal display cell for a liquid crystal display device comprising the steps of: a) deploying a sealing member on a first substrate; said sealing member forming a perimeter encircling a display area of said liquid crystal display cell and having an array of a plurality of excessive liquid crystal storage chambers positioned at a location adjacent to said perimeter; b) delivering at least one drop of liquid crystal on either one of said first substrate and a second substrate; c) assembling said first substrate and said second substrate wherein said first and second substrates sandwiching said sealing member and are aligned for image displaying operation of said liquid crystal display cell; d) breaking at least one opening between the containing space of said perimeter and the storage space of each of said at least one storage chambers; and e) discharging any excessive liquid crystal trapped within said perimeter into at least one of said plurality of storage chambers thereby enclosing an optimized amount of liquid crystal in said perimeter for defect-free implementation of said image displaying operation. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is a plane view schematically showing an LCD cell prepared on a mother glass with a sealed discharge port of the liquid crystal containing space in accordance with a preferred embodiment of the present invention;  
         [0016]      FIG. 2  is a cross-sectional view illustrating a section of the LCD cell according to a preferred embodiment of the present invention;  
         [0017]      FIG. 3  is a plane view schematically showing the delivery of drops of liquid crystal in the containing space of the LCD cell of  FIG. 1 ;  
         [0018]      FIG. 4  is a plane view schematically illustrating the spreading of liquid crystal in the containing space of the LCD cell after the aligned placement of the second substrate over the structure of  FIG. 3 ;  
         [0019]      FIG. 5  is a plane view schematically showing the LCD cell cut free from the mother glass system of  FIG. 4 ;  
         [0020]      FIG. 6  is a plane view schematically showing the sealing of the discharge port of the containing space of the LCD cell of  FIG. 5 ;  
         [0021]      FIG. 7  is a plane view schematically illustrating the spreading of liquid crystal in the containing space of the LCD cell in accordance with a second preferred embodiment of the present invention;  
         [0022]      FIG. 8  is a plane view schematically showing the LCD cell cut free from the mother glass system of  FIG. 7 ;  
         [0023]      FIG. 9  is a plane view schematically showing the sealing of the discharge port of the containing space of the LCD cell of  FIG. 8 ;  
         [0024]      FIG. 10  is a plane view schematically showing an LCD cell prepared on a mother glass with a number of storage chambers for excessive liquid crystal in accordance with another preferred embodiment of the present invention;  
         [0025]      FIG. 11  is a cross-sectional view illustrating a section of the LCD cell of  FIG. 7 ;  
         [0026]      FIG. 12  is a plane view schematically showing the delivery of drops of liquid crystal in the containing space of the LCD cell of  FIG. 7 ;  
         [0027]      FIG. 13  is a plane view schematically illustrating the spreading of liquid crystal in the containing space of the LCD cell after the aligned placement of the second substrate over the structure of  FIG. 9 ;  
         [0028]      FIG. 14  is a plane view schematically showing the LCD cell cut free from the mother glass system of  FIG. 10  and with one storage chamber opened for receiving excessive liquid crystal discharged from the main containing space; and  
         [0029]      FIGS. 15 and 16  are plane views schematically showing the opening up of more than one storage chamber for the storage of excessive liquid crystal from the containing space of the LCD cell. 
     
    
     DETAILED DESCRIPTION  
       [0030]      FIG. 1  is a plane view schematically showing an LCD cell prepared on a mother glass with a sealed discharge port of the liquid crystal containing space in accordance with the teaching of the present invention. Cross-sectional view of  FIG. 2  illustrates a section of the LCD cell constructed on the mother glass of  FIG. 1  taken along the A-A line. Reference is made simultaneously to the two drawings for a description of a preferred embodiment of the LCD cell structure of the present invention.  
         [0031]     Preferably, multiple LCD cells of the present invention can be made from a single mother glass.  FIG. 1  shows a section of a mother glass  100 , which is used as the basic substrate for the batch construction of LCD cells including cell  110  shown in its entirety. Each of the individual cells fabricated on the mother glass  100  can be separated physically in a later processing stage as will be described subsequently. Dashed lines in  FIG. 1  identify the boundary between cells on the same mother glass  100 .  
         [0032]     At this early stage of fabrication on the mother glass, each of the cells is seen defined by a sealing member generally encircling its own display area. An LCD cell constructed in accordance with the teaching of the present invention comprises a pair of transparent substrates aligned parallel to each other and forming a liquid crystal-containing space in between. In this depicted example, the two substrates include substrate  102  cut from the mother glass  100 .  
         [0033]     The two substrates are fixed to each other by a sealing member  111 , which has an excess liquid crystal discharge port  113 . As is shown, sealing member  111  for cell  110  is configured into a rectangular enclosure generally deployed along the edge of its boundary on the mother glass  100 . The sealing member  111  can be applied over the surface of the mother glass  100  as a viscous material using an automatic dispenser that comprises a nozzle of predetermined sealant discharge orifice size. After the sealing member  111  is cured in the subsequent processing stage, it serves to seal the liquid crystal-containing space between the two substrates. Preferably, liquid crystal is filled into the containing space in, for example, an ODF process step as will be described below.  
         [0034]     In a preferred embodiment of the LCD cell in accordance with the present invention such as exemplified in  FIG. 2 , substrate  102  (cut from the mother glass  100  of  FIG. 1 ) has a plurality of color filter sections arranged in a matrix of display pixels on the internal surface thereof. Generally identified by the reference numeral  212  in the drawing, each of the color filter sections may comprise independent filters for each of the three primary colors. In between every pair of consecutive color filter sections  212  in the matrix, segments of a light-shielding framework  214  is formed to avoid mutual interference between neighboring image display pixels. A transparent electrode layer  216  hosting a network of electrodes is formed covering both the color filter sections  212  and the light-shielding framework  214  over the entire surface area of the substrate  204 .  
         [0035]     Over the internal surface of the other substrate  102  opposite to  204 , as also illustrated in  FIG. 2 , is another matrix of thin-film transistors (TFT) as well as a matrix of pixel electrodes. Generally indicated by reference numeral  218  in the cross-sectional view, each of the transistors in the matrix is connected to a network of parallel data and gate lines (both not shown in the drawing). As is comprehensible, each of the thin-film transistors  218  for a corresponding color filter section  212  can be located adjacent to where a pair of data and gate lines intersect. Similarly, each of the pixel electrodes  220  is placed within the gridwork defined by the intersecting data and gate lines and substantially aligned with a corresponding color filter section  212 . All the TFTs, together with their corresponding color filter sections  212  and pixel electrodes  220  are arrayed in a display matrix corresponding to the image pixel matrix system within the display area of the LCD cell.  
         [0036]     In another preferred embodiment of the LCD cell in accordance with the present invention, the pair of substrates may include one featuring a color-filter-on-array (COA) filtering system and another paired opposite substrate with a corresponding electrode system. In still another embodiment of the present invention, the substrate pair can be replaced with one featuring the in-plane switching mode design.  
         [0037]      FIG. 3  is a plane view schematically showing the delivery of at least one drop  301  of liquid crystal in the containing space of the LCD cell in an ODF procedure. Amount of liquid crystal delivered in the at least one drop  301  is predetermined to match the volumetric capacity of the liquid crystal-containing space. Preferably, the delivery amount is slightly larger than the exact amount and also to cover the tolerance among different sets of substrate pairs for the mass production of the inventive LCD cells.  
         [0038]     Subsequently, a second substrate is placed on top of the structure of  FIG. 3 . This second substrate is placed in position with necessary alignment so that the color filter matrix can be properly aligned with the TFT matrix system described above.  
         [0039]      FIG. 4  is a plane view schematically illustrating the spreading of liquid crystal in the containing space of the LCD cell after the aligned placement of the second substrate over the structure of  FIG. 3 . The placement of the top substrate in position spreads the liquid crystal in the containing spaces for all cells batch-fabricated on the mother glass. For example, liquid crystal drops  301  delivered in  FIG. 3  become the filling liquid crystal  206  in the LCD cell  110  of  FIG. 4 . The placement of the top substrate also completes the construction of the sealed liquid crystal-containing space. The sealing member  111  may then be hardened to combine the two substrates in a permanently fixed manner.  
         [0040]     After the two substrates are secured relative to each other, the entire assembly is subject to a cutting procedure. The cutting can be performed along the cutting line generally identified in  FIG. 4  by the dashed line. In a preferred embodiment of the present invention, this cutting to release the multiple LCD cells from the mother glass can be performed along the dashed lines in  FIG. 4  without breaking the discharge port  113 . This prevents the contamination by excessive liquid crystal coming out of the containing space during this mass separation processing.  
         [0041]     A subsequent cutting can then be performed directly cutting through the channel mouth of the discharge port  113  when an individual LCD cell such as cell  110  shown in  FIG. 5  can be processed. The result of this subsequent cutting achieves an LCD as is schematically illustrated in the plane view of  FIG. 5 . Normally, the discharge port  113  allows for the containment of the discharge of excess liquid crystal delivered in the ODF process. With adequate control of the ODF delivery amount, the excessive liquid crystal can be contained entirely within the containing space. This leaves no contaminating liquid crystal residue over the external surface of the sealing member  111 .  
         [0042]     If, however, excessive liquid crystal is more than can be contained within the containing space, it can be discharged off the LCD cell without problem once the discharge port  113  is cut open. Methods such as cleaning known in the art can then be used to completely remove all excessive liquid crystal off the cell. After this, the discharge port  113  can be sealed utilizing a plugging sealant  114  and achieving an LCD cell assembly  610  as shown in  FIG. 6  containing adequate amount of liquid crystal for optimized image display.  FIG. 6  is a plane view schematically showing the sealing of the discharge port of the containing space of the LCD cell of  FIG. 5 .  
         [0043]     Preferably, the main enclosing sealing member  111  for the containing space and the plugging sealant  114  for the discharge port  113  are radiation-hardened sealant. Radiation-cured sealant materials such as UV-hardened ones are more preferable than heat-cured.  
         [0044]     Although not shown in the drawings, an LCD cell constructed in accordance with a preferred embodiment of the present invention may have the deployment of a matrix of regularly-populated spacers between its two substrates with a distribution density much higher than possible in the conventional cells. Spacers are used inside the liquid crystal-containing space of the cell to assist to support the rigidity of the thin and large-area substrates in order to prevent both from collapsing toward each other.  
         [0045]     Spacer population density inside the liquid crystal-containing space for conventional LCD cells manufactured employing ODF procedure is typically less than 0.15%, measuring the total spacer footprint area with respect to overall LCD cell display area. Lower spacer population density allows for relatively larger process window, which leads to easier manipulation and better result of ODF schemes in the fabrication of LCD cells. On the other hand, higher spacer population density results into higher cell mechanical rigidity. In accordance with the teaching of the present invention, the spacer population density becomes a disengaged factor for ODF process window in the manufacturing of an LCD cell. It is therefore, in accordance with the present invention, possible to deploy spacers in the cell at a population density much higher than the typical 0.15% conventionally achievable. In a preferred embodiment, it is possible to deploy spacers at a density up to nearly 2% of the total display area. This leads to an extremely rigid cell structure.  
         [0046]     A second preferred embodiment is schematically illustrated in  FIG. 7 ,  FIG. 8 , and  FIG. 9 . A subsequent cutting can then be performed directly cutting through the channel mouth of the discharge port  313  when an individual LCD cell such as cell  310  shown in  FIG. 8  can be processed which is subject to the problem of having excessive liquid crystal sealed in its containing space. Not every LCD cell cut loose from the mother glass requires this rework processing of excessive liquid crystal discharge. However, such rework does provide improvement to the overall costs of LCD cell manufacture due to the possibility of easy salvage of cells with excessively-filled liquid crystal.  
         [0047]     The result of this rework-cutting achieves an LCD as is schematically illustrated in the plane view of  FIG. 8 . The opening of the discharge port  313  can be achieved by breaking open the section of the sealing member  311  in between the two port-defining sections  313   a  and  313   b . The opening can be facilitated by, for example, burning the opening section utilizing a laser beam of adequate power and wavelength. Such a laser beam can open up the discharge port without inflicting damage to the other components of the cell close to the location of this burn-opening partly due to the fact that substrates enclosing the liquid crystal are transparent glass-based.  
         [0048]     In case of laser beam opening of the discharge port  313  as depicted in  FIG. 8 , the opening section of the sealing member  311  can be reduced to ball-like residuals  313   c  at the edges of the opening. Normally, the discharge port  313  allows for the containment of the discharge of excess liquid crystal delivered in the ODF process. With adequate control of the ODF delivery amount, the excessive liquid crystal can be contained entirely within the channel space of the discharge port  313 . This leaves no contaminating liquid crystal residue over the external surface of the sealing member  311 .  
         [0049]     If, however, excessive liquid crystal is more than can be contained within the channel of the discharge port  313 , it can be discharged off the LCD cell without problem once the discharge port  313  is cut open. Methods such as cleaning known in the art can then be used to completely remove all excessive liquid crystal off the cell. After this, the discharge port  313  can be sealed utilizing a plugging sealant  314  and achieving an LCD cell assembly  310  as shown in  FIG. 9  containing adequate amount of liquid crystal for optimized image display.  FIG. 9  is a plane view schematically showing the sealing of the discharge port of the containing space of the LCD cell of  FIG. 8 .  
         [0050]     Preferably, the main enclosing sealing member  311  for the containing space and the plugging sealant  314  for the discharge port  313  are radiation-hardened sealant. Radiation-cured sealant materials such as UV-hardened ones are more preferable than heat-cured.  
         [0051]     Although not shown in the drawings, an LCD cell constructed in accordance with the second preferred embodiment of the present invention may have the deployment of a matrix of regularly-populated spacers between its two substrates with a distribution density much higher than possible in the conventional cells. Spacers are used inside the liquid crystal-containing space of the cell to assist to support the rigidity of the thin and large-area substrates in order to prevent both from collapsing toward each other.  
         [0052]     Typical spacer population density inside the liquid crystal-containing space for conventional LCD cells is approximately 0.15%, measuring the total spacer footprint area with respect to overall LCD cell display area. Lower spacer population density allows for relatively larger process window, which leads to easier manipulation and better result of ODF schemes in the fabrication of LCD cells. On the other hand, higher spacer population density results into higher cell mechanical rigidity. In accordance with the teaching of the present invention, the spacer population density becomes a disengaged factor for ODF process window in the manufacturing of an LCD cell. It is therefore, in accordance with the present invention, to deploy spacers in the cell at a population density much higher than the conventionally-optimized 0.15%. In a preferred embodiment, it is possible to deploy the spacers up to 2% of the total display area, leading to an extremely rigid cell structure.  
         [0053]      FIG. 10  is a plane view schematically showing an LCD cell prepared on a mother glass with a number of storage chambers for excessive liquid crystal in accordance with another preferred embodiment of the present invention. Cross-sectional view of  FIG. 11  illustrates a section of the LCD cell of constructed on the mother glass of  FIG. 10  taken along the B-B line. Reference is made simultaneously to the two drawings for a description of the preferred embodiment of the LCD cell structure of the present invention.  
         [0054]     Preferably, LCD cells of the present invention can be made in multiples from a single mother glass.  FIG. 10  shows a section of a mother glass  700 , which is used as the basic substrate for the batch construction of LCD cells including cell  710  shown in its entirety. As is comprehensible, each of the individual cells fabricated on the mother glass can be separated physically in a later processing stage as will be described subsequently. Dashed lines in the drawing identify the boundary between cells on the same mother glass  700 .  
         [0055]     At this early stage of fabrication on the mother glass, each of the cells is seen defined by a sealing member generally encircling its own display area. An LCD cell constructed in accordance with the teaching of the present invention comprises a pair of transparent substrates aligned parallel to each other and forming a liquid crystal-containing space in between. In this depicted example, the two substrates include substrate  702  cut from the mother glass  700 .  
         [0056]     The two substrates are fixed to each other by a sealing member  711 , which has an array of excess liquid crystal storage chambers generally identified by reference numeral  713 . The LCD cell structural configuration in accordance with another embodiment of the present invention illustrated in  FIG. 13  shows an arrangement of such an array of storage chambers made ready for reception of excessive liquid crystal to be removed from the main containing space of the cell. As is shown, an LCD cell of the present invention may be equipped with a number of storage chambers arranged in an arrayed manner near one edge of the display area of the cell. Each of the chambers is preferably made from the same sealing member material used to enclose the liquid crystal containing space  806  for the cell assembly  710 . As is comprehensible, each of the chambers may be constructed to have the same or different volumetric capacity.  
         [0057]     As is shown in  FIG. 13 , sealing member  711  is configured into a rectangular enclosure generally deployed along the edge of its boundary on the mother glass  700 . The sealing member  711  can be applied over the surface of the mother glass  700  as a viscous material using an automatic dispenser that comprises a nozzle of predetermined sealant discharge orifice size. When the sealing member  711  is cured in the subsequent processing stages, it serves to seal the liquid crystal-containing space between the two substrates. Preferably, liquid crystal is filled into the containing space in, for example, an ODF process step as will be described below.  
         [0058]     In the preferred embodiment of the LCD cell in accordance with the present invention such as exemplified in  FIG. 11 , substrate  804  has a plurality of color filter sections arranged in a matrix of display pixels on the internal surface thereof. Generally identified by the reference numeral  812  in the drawing, each of the color filter sections may comprise independent filters for each of the three primary colors. In between every pair of consecutive color filter sections  812  in the matrix, segments of a light-shielding framework  814  is formed to avoid mutual interference between neighboring image display pixels. A transparent electrode layer  816  hosting a network of electrodes is formed covering both the color filter sections  812  and the light-shielding framework  814  over the entire surface area of the substrate  804 .  
         [0059]     Over the internal surface of the other substrate  804  opposite to  702 , as also illustrated in  FIG. 11 , is another matrix of thin-film transistors (TFT) as well as a matrix of pixel electrodes. Generally indicated by reference numeral  818  in the cross-sectional view, each of the transistors in the matrix is connected to a network of parallel data and gate lines (both not shown in the drawing). As is comprehensible, each of the thin-film transistors  818  for a corresponding color filter section  812  can be located adjacent to where a corresponding pair of data and gate lines intersect. Similarly, each of the pixel electrodes  820  is placed within the gridwork defined by the intersecting data and gate lines and substantially aligned with a corresponding color filter section  812 . All the TFTs, together with their corresponding color filter sections  812  and pixel electrodes  820  are arrayed in a display matrix corresponding to the image pixel matrix system within the display area of the LCD cell.  
         [0060]     In another preferred embodiment of the LCD cell in accordance with the present invention, the pair of transparent substrates may include one featuring a color-filter-on-array (COA) filtering system and another paired opposite substrate with a corresponding electrode system. In still another embodiment of the present invention, the substrate pair can be replaced with one featuring the in-plane switching mode design.  
         [0061]      FIG. 12  is a plane view schematically showing the delivery of at least one drop  901  of liquid crystal in the containing space of the LCD cell in an ODF procedure. Amount of liquid crystal delivered in the drop  901  is predetermined to match the volumetric capacity of the liquid crystal-containing space. Preferably, the delivery amount is slightly larger than the exact amount and also to cover the tolerance among different sets of substrate pairs for the mass production of the inventive LCD cells.  
         [0062]     Subsequently, a second substrate is placed on top of the structure of  FIG. 12 . As is comprehensible, this second substrate is placed in position with necessary alignment so that the color filter matrix can be properly aligned with the TFT matrix system described above.  
         [0063]      FIG. 13  is a plane view schematically illustrating the spreading of liquid crystal in the containing space of the LCD cell after the aligned placement of the second substrate over the structure of  FIG. 12 . The placement of the top substrate in position spreads the liquid crystal in the containing spaces for all cells batch-fabricated on the mother glass. For example, liquid crystal drops  901  delivered in  FIG. 12  become the filling liquid crystal  806  in the LCD cell  710  of  FIG. 13 . In this process, liquid crystal trapped inside the containing space of a cell may be in excess to the volumetric capacity optimized for the containing space. As is known to those skilled in the art, excessive liquid crystal in the containing space represents quality problem for the LCD cell. For those cells trapping excessive amount of liquid crystal, rework processing after the physical separation from the mother glass system become necessary. The inventive cell structure described herein allows for easy rework adjustment as will be described in the following paragraphs.  
         [0064]     The placement of the top substrate also completes the construction of the sealed liquid crystal-containing space regardless of whether the liquid crystal filled is excessive or not. The sealing member  711  may then be hardened to combine the two substrates in a permanently fixed manner. After the two substrates are secured relative to each other, the entire assembly is subject to a cutting procedure. The cutting can be performed along the cutting line generally identified in  FIG. 13  by the dashed line.  
         [0065]     As is schematically illustrated in the plane view of  FIG. 14 , the LCD cell  710  is cut free from the mother glass system of  FIG. 13 . The array of excessive liquid crystal storage chambers  713  allows for the containment of the discharge of excess liquid crystal delivered in the ODF process when necessary. With adequate control of the ODF delivery amount, the excessive liquid crystal can be contained entirely within array of storage chambers  713 . Each of  FIGS. 14, 15  and  16  respectively illustrates an embodiment of the inventive LCD cell structural configuration reworked for adjustment to achieve the containment of the optimized amount of liquid crystal in the containing space for defect-free operation of the display device constructed out of the cell.  
         [0066]      FIG. 14  is a plane view schematically showing the LCD cell cut free from the mother glass system of  FIG. 13  and with one storage chamber opened for receiving excessive liquid crystal discharged from the main containing space.  FIGS. 15 and 16  are plane views schematically showing the opening up of more than one storage chamber for the storage of excessive liquid crystal from the containing space of the LCD cell.  
         [0067]     LCD cell  1100  shown in the plane view of  FIG. 14  has a ready and easy remedy in case excessive liquid crystal is sealed inside the containing space. In case of such a defect, the sealing member  1111  for the cell  1110  at the section separating the storage chamber  1113 A can be broken as is illustrated in the drawing. This can be achieved via, for example, irradiation by a laser beam set to predetermined power rating. Such irradiation can be conveniently conducted via either of the transparent substrates of the cell.  
         [0068]     Opening up of the storage chamber  1113 A in the cell  1110  of  FIG. 14  allows for the discharge of the excessive liquid crystal trapped inside the containing space  1106 . As is comprehensible, structural sections of the array of storage chambers  1113  of the main sealing member  1111  can be located under either of the two cell substrates where no other cell component such as electrodes or electrically conductive trace is formed. Also as is comprehensible, discharge of excessive liquid crystal from the main containing space  1106  into the opened storage chamber can be automatic as a result of internal pressure in the containing space due to the excessiveness of the enclosed liquid crystal. Alternatively, external pressure may also be employed to discharge the excess of liquid crystal in the containing space into the storage chamber opened.  
         [0069]     In case one storage chamber  1113 A is insufficient to receive the entire excessive amount needs to be discharged from the main containing space, more storage chambers can be opened to the main space. The number of storage chambers need to be opened is dependent on the amount of liquid crystal that is excessive to necessary.  FIGS. 15 and 16  are plane views schematically showing the opening up of more than one storage chamber for the storage of excessive liquid crystal from the containing space of the LCD cell.  
         [0070]     Consider, for example, the case of an LCD cell manufactured to hold more than necessary amount of liquid crystal within its containing space. In this case, a first chamber  1213 A shown in  FIG. 15  can be opened to the main containing space by breaking down its wall toward the containing space. This can be implemented utilizing, for example, the laser irradiation method described above. When the chamber  1213 A is opened to the main containing space  1206  the cell  1210 , a predetermined amount of excessive liquid crystal can be discharged into this chamber. If this discharge of liquid crystal into the storage chamber  1213 A achieves the reduction of the total amount of liquid crystal in the containing space  1206  of the cell  1210  down to the normal level, the cell  1210  is repaired and salvaged. If, however, one single storage chamber  1213 A is not sufficient to reduce the total liquid crystal amount down to normal, more storage chambers can be used. As is illustrated in  FIG. 15 , a second storage chamber  1213 B is opened to receive its share of excessive liquid crystal from the main containing space of the cell assembly  1210 . The rework scheme of opening up storage chambers to the main containing space can be repeated until the right total amount of liquid crystal in the cell&#39;s main containing space is achieved.  FIG. 16  depicts an example of another rework in accordance with the present invention.  
         [0071]     Reworked LCD cells  1100 ,  1210  and  1310  illustrated in  FIGS. 14, 15  and  16  respectively become ones holding an adequate amount of liquid crystal within their containing spaces and are now able to qualify quality control. Due to the innovative LCD cell construction and the rework scheme thus possible, these cells are therefore salvation from defective products that would otherwise have to be wasted.  
         [0072]     As is comprehensible to those skilled in the art, each of the storage chambers for the LCD cell assembly described in FIGS.  14  to  16  may be made to maintain a negative air pressure, preferably vacuum, when they were formed. This is relatively easy since ODF procedure to fill liquid crystal is normally conducted in a vacuum operating space. Such negative pressure assists in the automatic sucking of excessive liquid crystal into themselves from the main containing space. This negative-pressure arrangement in all storage chambers is advantageous in that the withdraw of excessive liquid crystal from the cell main containing space produces no contaminating liquid crystal droplets to be removed off the LCD cell assembly. All the excessive liquid crystal material remains on-board, virtually eliminating the contamination problem for the subsequent fabrication processing steps of the cell assembly.  
         [0073]     Preferably, the main enclosing sealing member  711  for the containing space and the sealant for the array of excessive liquid crystal storage chambers  713  are radiation-hardened sealant. Radiation-cured sealant materials such as UV-hardened ones are more preferable than heat-cured.  
         [0074]     Although not shown in the drawings, an LCD cell constructed in accordance with a preferred embodiment of the present invention may have the deployment of a matrix of regularly-populated spacers between its two substrates. Spacers are used inside the liquid crystal-containing space of the cell to assist to support the rigidity of the thin and large-area substrates in order to prevent both from collapsing toward each other.  
         [0075]     As is known to those in the art, lower spacer population density allows for relatively larger process window, which leads to easier manipulation and better result of ODF schemes in the fabrication of LCD cells. On the other hand, however, higher spacer population density means higher cell mechanical rigidity, a highly-desirable characteristics. Spacer population density inside the liquid crystal-containing space of conventional LCD cells produced employing ODF procedure must, due to fabrication process window considerations, be below approximately 0.15%, measuring the total spacer footprint area with respect to overall LCD cell display area. In LCD cells manufactured in accordance with the teaching of the present invention, this disadvantageous limitation does not apply. Preferred spacer population density inside the liquid crystal-containing space of present invention can be advantageously much higher than that of the conventional cells.  
         [0076]     While the above is a full description of the specific embodiments, various modifications, alternative constructions and equivalents may be used. Although the LCD cell structure of the present invention allows for the reworking adjustment of the release of the excessiveness of the liquid crystal into the storage space, it does not imply that all cells manufactured require this rework processing. This is particularly true in an established and experienced LCD manufacturing facility implementing the idea of the present invention. With this possibility of allowing a rework, cells that would originally have to be discarded due to the enclosure of an incorrect amount of liquid crystal can now be salvaged and reworked into a fully-qualified cell. Therefore, the above description and illustrations should not be taken as limiting the scope of the present invention which is defined by the appended claims.