Patent Publication Number: US-2020285118-A1

Title: Liquid crystal display

Description:
TECHNICAL FIELD 
     The present invention relates to a liquid crystal display. 
     BACKGROUND ART 
     In a common liquid crystal display of a horizontal field system, a liquid crystal layer is arranged between a polarizer adjacent to an incoming surface and a polarizer adjacent to an outgoing surface. The polarizer adjacent to the outgoing surface has a polarizing axis perpendicular to the polarizing axis of the polarizer adjacent to the incoming surface. Thus, as the birefringence amount of a liquid crystal layer becomes greater, light having been transmitted through the polarizer adjacent to the incoming surface and the liquid crystal layer sequentially becomes capable of being transmitted through the polarizer adjacent to the outgoing surface more easily. In this way, the light transmittance of a liquid crystal panel is increased. 
     In the liquid crystal display of the horizontal field system, an alignment film is provided for alignment of liquid crystal molecules in such a manner that a liquid crystal director, which shows an alignment direction for liquid crystal molecules which forms the liquid crystal layer and is a uniaxial and optical index ellipsoid, is placed in an extinction position. Hence, when a horizontal field does not pass through the liquid crystal layer, the liquid crystal director is in the extinction position and the birefringence amount of the liquid crystal layer becomes minimum. In this case, the light transmittance of the liquid crystal panel becomes minimum. Meanwhile, when the horizontal field passes through the liquid crystal layer, the liquid crystal director is rotated from the extinction position in a horizontal plane and the birefringence amount of the liquid crystal layer is increased, thereby increasing the light transmittance of the liquid crystal panel. 
     In the liquid crystal display of the horizontal field system, the light transmittance of the liquid crystal panel is increased by rotating the liquid crystal director in a horizontal plane. This characteristically results in small change between directions of observation in terms of the brightness or contrast of image displayed on the liquid crystal panel. For this reason, the liquid crystal display of the horizontal field system has a wide viewing angle. 
     The horizontal field system includes an in-plane switching (IPS (registered trademark)) system, a fringe-field switching (FFS) system, and systems derived from these systems. 
     In a liquid crystal display of the IPS system, two line-like electrodes forming a slit electrode are in the same layer, extend in the same extension direction, face each other, and function as liquid crystal driving electrodes. One of the two line-like electrodes is given a signal potential. The other of the two line-like electrodes is given a ground potential. A horizontal field responsive to the applied signal potential is generated between the two line-like electrodes. The generated horizontal field rotates the liquid crystal director from the extinction position in a horizontal plane to increase the birefringence amount of the liquid crystal layer, thereby increasing the light transmittance of the liquid crystal panel. 
     In the liquid crystal display of the IPS system, however, the liquid crystal director is rotated from the extinction position mainly by the horizontal field generated between the two line-like electrodes. Hence, a field for rotating the liquid crystal director from the extinction position is not generated on the two line-like electrodes, so that the liquid crystal director is always in the extinction position on the two line-like electrodes. This causes substantially no passage of light through a region where the two line-like electrodes are arranged after the light enters the liquid crystal panel from a backlight, for example. Further, an electric line of force of the horizontal field does not follow a completely horizontal line but it follows a upwardly convex gentle curve. This fails to provide the liquid crystal layer with a birefringence amount uniform between the two line-like electrodes. Hence, even if the signal potential becomes a potential for maximizing the light transmittance of the liquid crystal panel, the light transmittance of the liquid crystal panel still has a drop between the two line-like electrodes. Due to these circumstances, the liquid crystal display of the IPS system finds difficulty in increasing the maximum light transmittance of the liquid crystal panel. 
     In a liquid crystal display of the FFS system, a line-like electrode forming a slit electrode is in a layer above an insulating layer and a sheet-like electrode is in a layer below the insulating layer. The line-like electrode and the sheet-like electrode function as liquid crystal driving electrodes. The line-like electrode is given a signal potential. The sheet-like electrode is given a ground potential. A fringe field responsive to the applied signal potential is generated between the line-like electrode and the sheet-like electrode. The generated fringe field rotates the liquid crystal director from the extinction position in a horizontal plane to increase the birefringence amount of the liquid crystal layer, thereby increasing the light transmittance of the liquid crystal panel. 
     Additionally, in the liquid crystal display of the FFS system, the liquid crystal director is rotated from the extinction position by the fringe field generated between the line-like electrode and the sheet-like electrode, extending over a wide range, and following an upwardly convex curve. This generates a field on the line-like electrode for rotating the liquid crystal director from the extinction position, so that the liquid crystal director can be placed in a position other than the extinction position, also on the line-like electrode. For this reason, the liquid crystal display of the FFS system makes it possible to increase the maximum light transmittance of the liquid crystal panel more easily than the liquid crystal display of the IPS system. 
     In the liquid crystal display of the horizontal field system, an angle of rotation of the liquid crystal director is large. This causes a disadvantage that response speed is low, compared to a liquid crystal display of a system such as a twisted nematic (TN) system or a vertical alignment (VA) system, for example. This advantage becomes notable particularly during the falling time of making a transition from a state in which a horizontal field passes through a liquid crystal layer to a state in which the horizontal field does not pass through the liquid crystal layer. 
     The following explains reason why the disadvantage of low response speed notable particularly during the falling time. In a common liquid crystal display of the horizontal field system in which a driving voltage is set at 0 V for display of black and the driving voltage is set at a maximum driving voltage for display of white, during rising time of making a transition from a state in which a horizontal field does not pass through a liquid crystal layer to a state in which the horizontal field passes through the liquid crystal layer, response speed can be increased by applying an overdrive voltage to a liquid crystal driving electrode for generating a horizontal field. During the falling time, however, response speed is governed by anchoring energy for aligning liquid crystal molecules in such a manner as to place the liquid crystal director in the extinction position and by the elasticity and viscosity of liquid crystal forming the liquid crystal layer, making it difficult to increase response speed. 
     A technique disclosed in patent document 1 is an example of a technique used for eliminating such a disadvantage. 
     In the technique disclosed in patent document 1, a plurality of rectangular openings (26A) is provided at a common electrode (26). The rectangular openings (26A) extend in the same extension direction and face a pixel electrode (24). One long side of the opening (26A) faces the other long side of the opening (26A) in the width direction of the opening (26A). Liquid crystal molecules in a neighboring region of the one long side of the opening (26A) are rotated and aligned in the opposite direction to liquid crystal molecules in a neighboring region of the other long side of the opening (26A). By doing so, response speed is increased (paragraph 0018). 
     PRIOR ART DOCUMENTS 
     Patent Documents 
     
         
         Patent Document 1: Japanese Patent Application Laid-Open No. 2013-109309 
       
    
     SUMMARY 
     Problem to be Solved by the Invention 
     The conventional technique represented by the technique disclosed in patent document 1 allows increase in response speed, even during the falling time of making a transition from a state in which a horizontal field passes through the liquid crystal layer to a state in which the horizontal field does not pass through the liquid crystal layer. 
     However, the conventional technique represented by the technique disclosed in patent document 1 necessitates a complicated structure of the liquid crystal driving electrode for generating a horizontal field, so that an advanced patterning technique is required for forming the liquid crystal driving electrode. 
     The present invention is intended to solve this problem. The problem to be solved by the present invention is to shorten response time during falling time of making a transition from a state in which a horizontal field passes through a liquid crystal layer to a state in which the horizontal field does not pass through the liquid crystal layer in a liquid crystal display of a horizontal field system without necessitating a complicated structure of an electrode for generating a horizontal field. 
     Means to Solve the Problem 
     A first aspect of the present invention relates to a liquid crystal display. 
     The liquid crystal display includes a first substrate, a second substrate, and a liquid crystal layer. The liquid crystal layer is caught between the first substrate and the second substrate and contains liquid crystal molecules. 
     The first substrate includes a first pixel electrode, a second pixel electrode, and an insulating film. The first pixel electrode includes line-like segments extending in a particular direction. The second pixel electrode includes a sheet-like electrode involved in a field from the first pixel electrode. The insulating film separates the first pixel electrode from the second pixel electrode in the thickness direction of the first substrate to insulate the first pixel electrode from the second pixel electrode. 
     The first substrate includes a first alignment film. The first alignment film has a main surface forming a main surface of the first substrate, contacting the liquid crystal layer, and having an alignment capability of aligning the liquid crystal molecules in a particular alignment direction. 
     The first substrate includes first line-like partitions and second line-like partitions. The first line-like partitions are arranged on the line-like segments of the first pixel electrode and extend in a direction substantially parallel to a direction of the first alignment film. The second line-like partitions are arranged between the line-like segments of the first pixel electrode and extend in a direction substantially parallel to the direction of the first alignment film. 
     The first substrate includes a second alignment film. The second alignment film covers the first line-like partitions and the second line-like partitions, and has a surface contacting the liquid crystal layer and having an alignment capability of aligning the liquid crystal molecules in the particular alignment direction. 
     A second aspect of the present invention relates to a liquid crystal display. 
     The liquid crystal display includes a first substrate, a second substrate, and a liquid crystal layer. The liquid crystal layer is caught between the first substrate and the second substrate and contains liquid crystal molecules. 
     The first substrate includes a first pixel electrode and a second pixel electrode. The first pixel electrode includes line-like segments extending in a particular direction. The second pixel electrode extends in an extension direction substantially parallel to the first pixel electrode and includes line-like segments arranged alternately with the line-like segments of the first pixel electrode. 
     The first substrate includes a first alignment film. The first alignment film has a main surface forming a main surface of the first substrate, contacting the liquid crystal layer, and having an alignment capability of aligning the liquid crystal molecules in a particular alignment direction. 
     The first substrate includes first line-like partitions and second line-like partitions. The first line-like partitions are arranged on the line-like segments of the first pixel electrode and substantially parallel to a direction of the first alignment film. The second line-like partitions are arranged on the line-like segments of the second pixel electrode and substantially parallel to the direction of the first alignment film. 
     The first substrate includes a second alignment film. The second alignment film covers the first line-like partitions and the second line-like partitions, and has a surface contacting the liquid crystal layer and having an alignment capability of aligning the liquid crystal molecules in the particular alignment direction. 
     A third aspect of the present invention relates to a liquid crystal display. 
     The liquid crystal display includes a first substrate, a second substrate, and a liquid crystal layer. The liquid crystal layer is caught between the first substrate and the second substrate and contains liquid crystal molecules. 
     The first substrate includes a first pixel electrode and a second pixel electrode. The first pixel electrode includes line-like segments extending in a particular direction. The second pixel electrode extends in an extension direction substantially parallel to the first pixel electrode and includes line-like segments arranged alternately with the line-like segments of the first pixel electrode. 
     The first substrate includes a first alignment film. The first alignment film has a main surface forming a main surface of the first substrate, contacting the liquid crystal layer, and having an alignment capability of aligning the liquid crystal molecules in a particular alignment direction. 
     The first substrate includes line-like partitions. The line-like partitions are arranged on the line-like segments of the first pixel electrode and substantially parallel to a direction of the first alignment film. 
     The first substrate includes a second alignment film. The second alignment film covering the line-like partitions, and has a surface contacting the liquid crystal layer and having an alignment capability of aligning the liquid crystal molecules in the particular alignment direction. 
     A fourth aspect of the present invention relates to a liquid crystal display. 
     The liquid crystal display includes a first substrate, a second substrate, and a liquid crystal layer. The liquid crystal layer is caught between the first substrate and the second substrate and contains liquid crystal molecules. 
     The first substrate includes line-like partitions. The line-like partitions are arranged on line-like segments of a first pixel electrode and extend in a direction substantially parallel to a direction of a first alignment film. 
     The first substrate includes the first pixel electrode, a second pixel electrode, and an insulating film. The first pixel electrode includes the line-like segments extending in a particular direction. The second pixel electrode includes a sheet-like electrode involved in a field from the first pixel electrode. The insulating film separates the first pixel electrode from the second pixel electrode in the thickness direction of the first substrate to insulate the first pixel electrode from the second pixel electrode. 
     The first substrate includes the first alignment film. The first alignment film has a main surface forming a main surface of the first substrate, contacting the liquid crystal layer, and having an alignment capability of aligning the liquid crystal molecules in a particular alignment direction. 
     The first substrate includes the line-like partitions. The line-like partitions are arranged on the line-like segments of the first pixel electrode and extend in the direction substantially parallel to the direction of the first alignment film. 
     The first substrate includes a second alignment film. The second alignment film covers the line-like partitions, and has a surface contacting the liquid crystal layer and having an alignment capability of aligning the liquid crystal molecules in the particular alignment direction. 
     A fifth aspect of the present invention relates to a liquid crystal display. 
     The liquid crystal display includes a first substrate, a second substrate, and a liquid crystal layer. The liquid crystal layer is caught between the first substrate and the second substrate and contains liquid crystal molecules. 
     The first substrate includes a first pixel electrode, a second pixel electrode, and an insulating film. The first pixel electrode includes line-like segments extending in a particular direction. The second pixel electrode includes a sheet-like electrode involved in a field from the first pixel electrode. The insulating film separates the first pixel electrode from the second pixel electrode in the thickness direction of the first substrate to insulate the first pixel electrode from the second pixel electrode. 
     The first substrate includes a first alignment film. The first alignment film has a main surface forming a main surface of the first substrate, contacting the liquid crystal layer, and having an alignment capability of aligning the liquid crystal molecules in a particular alignment direction. 
     The substrate includes line-like partitions. The line-like partitions are arranged between the line-like segments of the first pixel electrode and extend in a direction substantially parallel to a direction of the first alignment film. 
     The first substrate includes a second alignment film. The second alignment film covers the line-like partitions, and has a surface contacting the liquid crystal layer and having an alignment capability of aligning the liquid crystal molecules in the particular alignment direction. 
     Effects of the Invention 
     According to the present invention, in the liquid crystal display of the horizontal field system, return of a liquid crystal director to an extinction position is encouraged by the alignment capability of the surface of the alignment film covering the partition during falling time of making a transition from a state in which a horizontal field passes through the liquid crystal layer to a state in which the horizontal field does not pass through the liquid crystal layer. This makes it possible to shorten response time during the falling time without necessitating a complicated structure of an electrode for generating the horizontal field. 
     These 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 DRAWINGS 
         FIG. 1  is a perspective view illustrating a liquid crystal display of each of a first to sixth embodiments. 
         FIG. 2  is a sectional view illustrating a section of a liquid crystal panel provided in the liquid crystal display of each of the first to sixth embodiments. 
         FIG. 3  is a plan view illustrating a thin film transistor (TFT) substrate, a printed board, and an integrated circuit chip provided in the liquid crystal display of each of the first to sixth embodiments. 
         FIG. 4  is a plan view illustrating planar arrangement of a line, an electrode, and a semiconductor channel layer provided in the liquid crystal display of each of the first and third embodiments. 
         FIG. 5  is a plan view illustrating planar arrangement of an organic planarizing film, a partition, and an alignment film provided in the liquid crystal display of the first embodiment. 
         FIG. 6  is a sectional view illustrating a TFT substrate and a liquid crystal layer provided in the liquid crystal display of the first embodiment. 
         FIG. 7  is a sectional view illustrating the TFT substrate and the liquid crystal layer provided in the liquid crystal display of the first embodiment. 
         FIG. 8  is a sectional view illustrating the TFT substrate and the liquid crystal layer provided in the liquid crystal display of the first embodiment. 
         FIG. 9  is a schematic view illustrating a structure model used for theoretically analyzing response speed during falling time in the absence of a partition such as the partition provided in the liquid crystal display of the first embodiment. 
         FIG. 10  is a schematic view illustrating a structure model used for theoretically analyzing response speed during the falling time in the absence of a partition such as the partition provided in the liquid crystal display of the first embodiment. 
         FIG. 11  is a schematic view illustrating a structure model used for theoretically analyzing response speed during the falling time in the presence of a partition such as the partition provided in the liquid crystal display of the first embodiment. 
         FIG. 12  is a schematic view illustrating a structure model used for theoretically analyzing response speed during the falling time in the presence of a partition such as the partition provided in the liquid crystal display of the first embodiment. 
         FIG. 13  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the absence of a partition such as the partition provided in the liquid crystal display of the first embodiment. 
         FIG. 14  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the presence of a partition such as the partition provided in the liquid crystal display of the first embodiment. 
         FIG. 15  is a graph showing response curves obtained by evaluating response characteristics using the structure model in the absence of a partition illustrated in  FIG. 13  and the structure model in the presence of a partition illustrated in  FIG. 14 . 
         FIG. 16  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the presence of a partition such as the partition provided in the liquid crystal display of the first embodiment. 
         FIG. 17  is a graph showing change in a rising period and a falling period resulting from the height of a partition determined by evaluating response characteristics using the structure model illustrated in  FIG. 16 . 
         FIG. 18  is a plan view illustrating planar arrangement of a line, an electrode, and a semiconductor channel layer provided in the liquid crystal display of each of the second and fourth to sixth embodiments. 
         FIG. 19  is a plan view illustrating planar arrangement of an organic planarizing film, a partition, and an alignment film provided in the liquid crystal display of the second embodiment. 
         FIG. 20  is a sectional view illustrating a TFT substrate and a liquid crystal layer provided in the liquid crystal display of the second embodiment. 
         FIG. 21  is a sectional view illustrating the TFT substrate and the liquid crystal layer provided in the liquid crystal display of the second embodiment. 
         FIG. 22  is a sectional view illustrating the TFT substrate and the liquid crystal layer provided in the liquid crystal display of the second embodiment. 
         FIG. 23  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the absence of a partition such as the partition provided in the liquid crystal display of the second embodiment. 
         FIG. 24  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the presence of a partition such as the partition provided in the liquid crystal display of the second embodiment. 
         FIG. 25  is a graph showing response curves obtained by evaluating response characteristics using the structure model in the absence of a partition illustrated in  FIG. 23  and the structure model in the presence of a partition illustrated in  FIG. 24 . 
         FIG. 26  is a plan view illustrating planar arrangement of an organic planarizing film, an electrode, a partition, and an alignment film provided in the liquid crystal display of the third embodiment. 
         FIG. 27  is a sectional view illustrating a TFT substrate and a liquid crystal layer provided in the liquid crystal display of the third embodiment. 
         FIG. 28  is a sectional view illustrating the TFT substrate and the liquid crystal layer provided in the liquid crystal display of the third embodiment. 
         FIG. 29  is a sectional view illustrating the TFT substrate and the liquid crystal layer provided in the liquid crystal display of the third embodiment. 
         FIG. 30  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the presence of a partition such as the partition provided in the liquid crystal display of the third embodiment. 
         FIG. 31  is a graph showing response curves obtained by evaluating response characteristics using the structure model in the absence of a partition illustrated in  FIG. 13  and the structure model in the presence of a partition illustrated in  FIG. 30 . 
         FIG. 32  is a plan view illustrating planar arrangement of an organic planarizing film, a partition, and an alignment film provided in the liquid crystal display of the fourth embodiment. 
         FIG. 33  is a sectional view illustrating a TFT substrate and a liquid crystal layer provided in the liquid crystal display of the fourth embodiment. 
         FIG. 34  is a sectional view illustrating the TFT substrate and the liquid crystal layer provided in the liquid crystal display of the fourth embodiment. 
         FIG. 35  is a sectional view illustrating the TFT substrate and the liquid crystal layer provided in the liquid crystal display of the fourth embodiment. 
         FIG. 36  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the presence of a partition such as the partition provided in the liquid crystal display of the fourth embodiment. 
         FIG. 37  is a graph showing response curves obtained by evaluating response characteristics using the structure model in the absence of a partition illustrated in  FIG. 23  and the structure model in the presence of a partition illustrated in  FIG. 36 . 
         FIG. 38  is a plan view illustrating planar arrangement of an organic planarizing film, an electrode, a partition, and an alignment film provided in the liquid crystal display of the fifth embodiment. 
         FIG. 39  is a sectional view illustrating a TFT substrate and a liquid crystal layer provided in the liquid crystal display of the fifth embodiment. 
         FIG. 40  is a sectional view illustrating the TFT substrate and the liquid crystal layer provided in the liquid crystal display of the fifth embodiment. 
         FIG. 41  is a sectional view illustrating the TFT substrate and the liquid crystal layer provided in the liquid crystal display of the fifth embodiment. 
         FIG. 42  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the presence of a partition such as the partition provided in the liquid crystal display of the fifth embodiment. 
         FIG. 43  is a graph showing response curves obtained by evaluating response characteristics using the structure model in the absence of a partition illustrated in  FIG. 23  and the structure model in the presence of a partition illustrated in  FIG. 42 . 
         FIG. 44  is a graph showing response curves resulting from replacement with a liquid crystal layer made of negative-type liquid crystal and obtained by evaluating response characteristics using the structure model in the absence of a partition illustrated in  FIG. 23  and the structure model in the presence of a partition illustrated in  FIG. 24 . 
     
    
    
     DESCRIPTION OF EMBODIMENT(S) 
     1. First Embodiment 
     1.1 Liquid Crystal Display 
     A first embodiment relates to a liquid crystal display of a horizontal field system (lateral field system). 
     The schematic view of  FIG. 1  is a perspective view illustrating the liquid crystal display of the first embodiment. 
     A liquid crystal display  1000  illustrated in  FIG. 1  is a transmissive liquid crystal display and includes a backlight  1010 , a liquid crystal panel  1011 , a printed board  1012 , and an integrated circuit chip  1013 . The liquid crystal display  1000  may include a structure other than these structures. A technique described below may be employed in a reflective or semi-transmissive liquid crystal display. 
     For display of an image on the liquid crystal display  1000 , the backlight  1010  emits light. The emitted light enters one main surface of the liquid crystal panel  1011 . After entering the one main surface of the liquid crystal panel  1011 , the light is transmitted through the liquid crystal panel  1011 . After being transmitted through the liquid crystal panel  1011 , the light exits through the other main surface of the liquid crystal panel  1011 . 
     For display of an image on the liquid crystal display  1000 , an image signal is input to the liquid crystal display  1000 , and the light transmittance of the liquid crystal panel  1011  is controlled using the input image signal. 
     As a result of the foregoing, the image responsive to the input image signal is displayed on the other main surface of the liquid crystal panel  1011 . 
     1.2 Liquid Crystal Panel 
     The schematic view of  FIG. 2  is a sectional view illustrating a section of the liquid crystal panel provided in the liquid crystal display of the first embodiment. 
     As illustrated in  FIGS. 1 and 2 , the liquid crystal panel  1011  includes a polarizer  1020 , a liquid crystal cell  1021 , and a polarizer  1022 . The liquid crystal panel  1011  may include a structure other than these structures. 
     As illustrated in  FIGS. 1 and 2 , the liquid crystal cell  1021  includes a thin film transistor (TFT) substrate  1030  as a first substrate, a liquid crystal layer  1031 , and a color filter (CF) substrate  1032  as a second substrate. The liquid crystal cell  1021  may include a structure other than these structures. 
     The liquid crystal layer  1031  is made of positive-type liquid crystal and caught between the inner main surface of the TFT substrate  1030  and the inner main surface of the CF substrate  1032 . The polarizer  1020  is affixed to the outer main surface of the TFT substrate  1030 . The polarizer  1022  is affixed to the outer main surface of the CF substrate  1032 . 
     For display of an image on the liquid crystal display  1000 , light emitted from the backlight  1010  is transmitted through the polarizer  1020 , the TFT substrate  1030 , the liquid crystal layer  1031 , the CF substrate  1032 , and the polarizer  1022  sequentially. 
     For display of an image on the liquid crystal display  1000 , a horizontal field to be applied to the liquid crystal layer  1031  is controlled using an image signal input to the liquid crystal display  1000 . The birefringence amount of the liquid crystal layer  1031  is controlled using the applied horizontal field, and the light transmittance of the liquid crystal panel  1011  is controlled using the birefringence amount of the liquid crystal layer  1031 . In this way, the light transmittance of the liquid crystal panel  1011  is controlled using the input image signal. 
     The printed board  1012  and the integrated circuit chip  1013  are arranged on the periphery of the TFT substrate  1030 . 
     1.3 Display Region 
     The schematic view of  FIG. 3  is a plan view illustrating the TFT substrate, the printed board, and the integrated circuit chip provided in the liquid crystal display of the first embodiment. 
     As illustrated in  FIG. 3 , the TFT substrate  1030  has a display region  1040  for display of images. 
     The display region  1040  includes a plurality of pixel regions arranged in a matrix. More specifically, the display region  1040  includes each pixel-regions-array  1050  consists of a plurality of pixel regions arranged in a direction indicated by an arrow AX, and each pixel-regions-array  1051  consists of a plurality of pixel regions arranged in a direction indicated by an arrow AY. Directions indicated by the arrows AX and AY are parallel to extension directions of the TFT substrate  1030 , the liquid crystal layer  1031 , and the CF substrate  1032 . The direction indicated by the arrow AY is perpendicular to the direction indicated by the arrow AX. The maxis arrangement may be replaced with arrangement not in a matrix pattern. 
     1.4 TFT Substrate 
     The schematic view of  FIG. 4  is a plan view illustrating planar arrangement of a line, an electrode, and a semiconductor channel layer provided in the liquid crystal display of the first embodiment. The schematic view of  FIG. 5  is a plan view illustrating planar arrangement of an organic planarizing film, a partition, and an alignment film provided in the liquid crystal display of the first embodiment.  FIGS. 6, 7, and 8  are sectional views each illustrating sections of the TFT substrate and the liquid crystal layer provided in the liquid crystal display of the first embodiment. 
       FIG. 6  illustrates a section taken at a position along a cutting line A-A′ in  FIGS. 4 and 5 .  FIG. 7  illustrates a section taken at a position along a cutting line B-B′ in  FIGS. 4 and 5 .  FIG. 8  illustrates a section taken at a position along a cutting line C-C′ in  FIGS. 4 and 5 . 
       FIGS. 4, 5, 6, 7, and 8  illustrate each pixel region  1060  forming the display region  1040  illustrated in  FIG. 3 . 
     A TFT substrate  1070  illustrated in  FIGS. 4, 5, 6, 7, and 8  becomes the TFT substrate  1030  illustrated in  FIGS. 1, 2, and 3 . A liquid crystal layer  1071  illustrated in  FIGS. 6, 7, and 8  becomes the liquid crystal layer  1031  illustrated in  FIG. 2 . 
       FIG. 4  illustrates an image signal line  1100 , a scanning line  1110 , a common potential line  1111 , a scanning line electrode  1120 , a semiconductor channel layer  1121 , an image signal line electrode  1122 , an image signal line electrode  1123 , an image signal line slit electrode  1124 , a common potential line slit electrode  1125 , an image signal line through hole group  1126 , and a common potential line through hole group  1127  provided in the TFT substrate  1070 . 
       FIG. 5  illustrates an organic planarizing film  1093 , a partition  1081 , and an alignment film  1082  provided in the TFT substrate  1070 . 
       FIG. 6  illustrates a glass substrate  1090 , a scanning line insulating film  1091 , an interlayer insulating film  1092 , the organic planarizing film  1093 , an alignment film  1094 , the common potential line  1111 , the scanning line electrode  1120 , the semiconductor channel layer  1121 , the image signal line electrode  1122 , the image signal line electrode  1123 , the image signal line slit electrode  1124 , the image signal line through hole group  1126 , the partition  1081 , and the alignment film  1082  provided in the TFT substrate  1070 . 
       FIG. 7  illustrates the glass substrate  1090 , the scanning line insulating film  1091 , the interlayer insulating film  1092 , the organic planarizing film  1093 , the alignment film  1094 , the image signal line  1100 , the scanning line  1110 , the common potential line  1111 , the common potential line slit electrode  1125 , the common potential line through hole group  1127 , the partition  1081 , and the alignment film  1082  provided in the TFT substrate  1070 . 
       FIG. 8  illustrates the glass substrate  1090 , the scanning line insulating film  1091 , the interlayer insulating film  1092 , the organic planarizing film  1093 , the alignment film  1094 , the image signal line slit electrode  1124 , the common potential line slit electrode  1125 , the partition  1081 , and the alignment film  1082  provided in the TFT substrate  1070 . 
     The image signal line  1100  is at each pixel-regions-array  1051  illustrated in  FIG. 3 . The scanning line  1110  and the common potential line  1111  are at each pixel-regions-array  1050  illustrated in  FIG. 3 . The scanning line electrode  1120 , the semiconductor channel layer  1121 , the image signal line electrode  1122 , the image signal line electrode  1123 , the image signal line slit electrode  1124 , the common potential line slit electrode  1125 , the image signal line through hole group  1126 , the common potential line through hole group  1127 , the partition  1081 , and the alignment film  1082  are at each pixel region  1060  illustrated in  FIG. 3 . 
     The TFT substrate  1070  may include a structure other than these structures. The scanning line insulating film  1091 , the scanning line electrode  1120 , the semiconductor channel layer  1121 , the image signal line electrode  1122 , and the image signal line electrode  1123  form a TFT. The TFT may be replaced with a switching element other than a TFT. The image signal line slit electrode  1124  and the common potential line slit electrode  1125  form a pixel electrode. 
     The glass substrate  1090  illustrated in  FIGS. 6, 7, and 8  is made of glass and have transparency and insulating properties. The glass substrate  1090  may be replaced with a substrate made of a material other than glass and having transparency and insulating properties. 
     The scanning line  1110  is arranged on an upper main surface  1130  of the glass substrate  1090  as illustrated in  FIG. 7 , extends in the direction indicated by the arrow AX as illustrated in  FIG. 4 , and extends across a plurality of pixel regions forming each pixel-regions-array  1050  illustrated in  FIG. 3 . 
     The common potential line  1111  is arranged on the upper main surface  1130  of the glass substrate  1090  as illustrated in  FIGS. 6 and 7 , extends in the direction indicated by the arrow AX as illustrated in  FIG. 4 , and extends across a plurality of pixel regions forming each pixel-regions-array  1050  illustrated in  FIG. 3 . 
     The scanning line electrode  1120  is arranged on the upper main surface  1130  of the glass substrate  1090  as illustrated in  FIG. 6 . As illustrated in  FIG. 4 , the scanning line electrode  1120  contacts the scanning line  1110  and is electrically connected to the scanning line  1110 . 
     The scanning line insulating film  1091  is stacked on the scanning line  1110 , the common potential line  1111 , and the scanning line electrode  1120  and arranged over the upper main surface  1130  of the glass substrate  1090  as illustrated in  FIGS. 6, 7, and 8 , and extends across a plurality of pixel regions forming the display region  1040  illustrated in  FIG. 3 . The scanning line insulating film  1091  separates the scanning line  1110 , the common potential line  1111 , and the scanning line electrode  1120  under the scanning line insulating film  1091  in the thickness direction of the TFT substrate  1070  from the image signal line  1100 , the semiconductor channel layer  1121 , the image signal line electrode  1122 , and the image signal line electrode  1123  over the scanning line insulating film  1091 , thereby insulating the scanning line  1110 , the common potential line  1111 , and the scanning line electrode  1120  from the image signal line  1100 , the semiconductor channel layer  1121 , the image signal line electrode  1122 , and the image signal line electrode  1123 . 
     The image signal line  1100  is stacked on the scanning line insulating film  1091  and arranged over the upper main surface  1130  of the glass substrate  1090  as illustrated in  FIG. 7 , and extends across a plurality of pixel regions forming each pixel-regions-array  1051  illustrated in  FIG. 3 . 
     As illustrated in  FIG. 6 , the semiconductor channel layer  1121  is stacked on the scanning line insulating film  1091  and arranged over the upper main surface  1130  of the glass substrate  1090 . The semiconductor channel layer  1121  faces the scanning line electrode  1120  across the scanning line insulating film  1091 . 
     As illustrated in  FIG. 6 , the image signal line electrode  1122  is stacked on the scanning line insulating film  1091  and the semiconductor channel layer  1121  and arranged over the upper main surface  1130  of the glass substrate  1090 . As illustrated in  FIG. 4 , the image signal line electrode  1122  contacts the image signal line  1100  and the semiconductor channel layer  1121  and is electrically connected to the image signal line  1100  and the semiconductor channel layer  1121 . 
     As illustrated in  FIG. 6 , the image signal line electrode  1123  is stacked on the scanning line insulating film  1091  and the semiconductor channel layer  1121  and arranged over the upper main surface  1130  of the glass substrate  1090 . As illustrated in  FIG. 4 , the image signal line electrode  1123  contacts the semiconductor channel layer  1121  and is electrically connected to the semiconductor channel layer  1121 . 
     As illustrated in  FIGS. 6, 7, and 8 , the interlayer insulating film  1092  is stacked on the scanning line insulating film  1091 , the image signal line  1100 , the semiconductor channel layer  1121 , the image signal line electrode  1122 , and the image signal line electrode  1123  and arranged over the upper main surface  1130  of the glass substrate  1090 . The interlayer insulating film  1092  separates the image signal line  1100 , the semiconductor channel layer  1121 , the image signal line electrode  1122 , and the image signal line electrode  1123  under the interlayer insulating film  1092  in the thickness direction of the TFT substrate  1070  from the image signal line slit electrode  1124  and the common potential line slit electrode  1125  over the interlayer insulating film  1092 , thereby insulating the image signal line  1100 , the semiconductor channel layer  1121 , the image signal line electrode  1122 , and the image signal line electrode  1123  from the image signal line slit electrode  1124  and the common potential line slit electrode  1125 . 
     As illustrated in  FIGS. 6, 7, and 8 , the organic planarizing film  1093  is stacked on the interlayer insulating film  1092  and arranged over the upper main surface  1130  of the glass substrate  1090 . 
     As illustrated in  FIGS. 6, 7, and 8 , the alignment film  1094  is stacked on the organic planarizing film  1093  and arranged over the upper main surface  1130  of the glass substrate  1090 . The alignment film  1094  has an upper main surface  1140  forming the upper main surface of the TFT substrate  1070  and contacting the liquid crystal layer  1071 . The upper main surface  1140  of the alignment film  1094  is subjected to alignment process by means of a rubbing or photo-alignment method, for example. Thus, the upper main surface  1140  of the alignment film  1094  has an alignment capability of aligning liquid crystal molecules in the liquid crystal layer  1071  in a particular alignment direction. 
     As illustrated in  FIGS. 6 and 8 , the image signal line slit electrode  1124  is stacked on the organic planarizing film  1093  and arranged over the upper main surface  1130  of the glass substrate  1090 . The image signal line slit electrode  1124  is a comb-like electrode and includes a line-like electrode  1150 , a line-like electrode  1151 , and a line-like electrode  1152  illustrated in  FIGS. 4 and 8 . The three line-like electrodes including the line-like electrodes  1150 ,  1151 , and  1152  may be replaced with two line-like electrodes or less, or four line-like electrodes or more. As illustrated in  FIG. 4 , each of the line-like electrodes  1150 ,  1151 , and  1152  is a line-like segment having a line-like planar shape as viewed in the thickness direction of the TFT substrate  1070  and extending in a particular extension direction indicated by the arrow AY. As illustrated in  FIGS. 4 and 8 , the line-like electrodes  1150 ,  1151 , and  1152  are arranged in an arrangement direction indicated by the arrow AX. 
     As illustrated in  FIGS. 7 and 8 , the common potential line slit electrode  1125  is stacked on the organic planarizing film  1093  and arranged over the upper main surface  1130  of the glass substrate  1090 . The common potential line slit electrode  1125  is a comb-like electrode extending in a direction substantially parallel to the image signal line slit electrode  1124 , and includes a line-like electrode  1160  and a line-like electrode  1161  illustrated in  FIGS. 4 and 8 . The two line-like electrodes including the line-like electrodes  1160  and  1161  may be replaced with one line-like electrode, or three line-like electrodes or more. As illustrated in  FIG. 4 , each of the line-like electrodes  1160  and  1161  is a line-like segment having a line-like planar shape as viewed in the thickness direction of the TFT substrate  1070  and extending in a particular extension direction indicated by the arrow AY, like each of the line-like electrodes  1150 ,  1151 , and  1152 . As illustrated in  FIGS. 4 and 8 , like the line-like electrodes  1150 ,  1151 , and  1152 , the line-like electrodes  1160  and  1161  are arranged in an arrangement direction indicated by the arrow AX. 
     As illustrated in  FIGS. 4 and 8 , the image signal line slit electrode  1124  and the common potential line slit electrode  1125  are arranged in such a manner that the line-like electrodes belonging to the image signal line slit electrode  1124  and the line-like electrodes belonging to the common potential line slit electrode  1125  are arranged alternately as viewed in the thickness direction of the TFT substrate  1070 . 
     As illustrated in  FIG. 6 , the image signal line through hole group  1126  penetrates the interlayer insulating film  1092 , the organic planarizing film  1093 , and the alignment film  1094 . The image signal line through hole group  1126  includes an image signal line through hole  1170 , an image signal line through hole  1171 , and an image signal line through hole  1172  illustrated in  FIG. 4 . Each of the image signal line through holes  1170 ,  1171 , and  1172  extends in the thickness direction of the TFT substrate  1070 . As illustrated in  FIG. 4 , the image signal line through holes  1170 ,  1171 , and  1172  contact the image signal line electrode  1123 , contact the line-like electrodes  1150 ,  1151 , and  1152  respectively at their one end portions, and electrically connect the line-like electrodes  1150 ,  1151 , and  1152  respectively to the image signal line electrode  1123 . 
     As illustrated in  FIG. 7 , the common potential line through hole group  1127  penetrates the interlayer insulating film  1092 , the organic planarizing film  1093 , and the alignment film  1094 . The common potential line through hole group  1127  includes a common potential line through hole  1180  and a common potential line through hole  1181  illustrated in  FIG. 4 . Each of the common potential line through holes  1180  and  1181  extends in the thickness direction of the TFT substrate  1070 . As illustrated in  FIG. 4 , the common potential line through holes  1180  and  1181  contact the common potential line  1111 , contact the line-like electrodes  1160  and  1161  respectively at their one end portions, and electrically connect the line-like electrodes  1160  and  1161  respectively to the common potential line  1111 . 
     1.5 Generation of Horizontal Field 
     In the TFT, in response to application of an ON signal to the scanning line electrode  1120  to become a gate electrode illustrated in  FIGS. 4 and 6 , the image signal line electrode  1122  to become a drain illustrated in  FIGS. 4 and 6  and the image signal line electrode  1123  to become a source illustrated in  FIGS. 4 and 6  become electrically continuous with each other. In response to application of an OFF signal to the scanning line electrode  1120  to become the gate, the image signal line electrode  1122  to become the drain and the image signal line electrode  1123  to become the source become electrically discontinuous with each other. 
     When the image signal line electrode  1122  and the image signal line electrode  1123  become electrically continuous with each other, the image signal line slit electrode  1124  illustrated in  FIGS. 4, 6, and 8  is given a signal potential as a first potential applied from the image signal line  1100  illustrated in  FIGS. 4 and 7  through the image signal line electrode  1122 , the semiconductor channel layer  1121 , the image signal line electrode  1123 , and the image signal line through hole group  1126  illustrated in  FIGS. 4 and 6 . 
     The common potential line slit electrode  1125  illustrated in  FIGS. 4, 7, and 8  is given a common potential as a second potential different from the first potential and applied from the common potential line  1111  illustrated in  FIGS. 4, 6 and 7  through the common potential line through hole group  1127  illustrated in  FIGS. 4 and 7 . 
     Thus, in response to application of an ON signal to the scanning line electrode  1120 , a driving voltage is applied between the image signal line slit electrode  1124  and the common potential line slit electrode  1125 . 
     When the driving voltage is applied between the image signal line slit electrode  1124  as a first pixel electrode and the common potential line slit electrode  1125  as a second pixel electrode, a horizontal field is generated between a field concentrated part  1200  as a second field concentrated part occupying a substantially entire upper surface of the line-like electrode  1160 , and a field concentrated part  1190  and a field concentrated part  1191  as a first field concentrated part respectively occupying substantially entire upper surfaces of the line-like electrodes  1150  and  1151  adjacent to the line-like electrode  1160 , as illustrated in  FIG. 8 . Further, a horizontal field is generated between a field concentrated part  1201  as the second field concentrated part occupying a substantially entire upper surface of the line-like electrode  1161 , and the field concentrated part  1191  and a field concentrated part  1192  as the first field concentrated part respectively occupying substantially entire upper surfaces of the line-like electrodes  1151  and  1152  adjacent to the line-like electrode  1161 . The generated horizontal fields pass through the liquid crystal layer  1071 , as indicated by electric lines of force  1210  illustrated in  FIG. 8 . 
     1.6 Partition 
     The partition  1081  includes a line-like partition  1220 , a line-like partition  1221 , and a line-like partition  1222  illustrated in  FIGS. 5 and 8 . The line-like partitions  1220 ,  1221 , and  1222  as a first line-like partition are arranged on the line-like electrodes  1150 ,  1151 , and  1152  respectively and are substantially parallel to the direction of the alignment film  1094 . The line-like partitions  1220 ,  1221 , and  1222  may be formed only in partial regions on the line-like electrodes  1150 ,  1151 , and  1152  respectively. As illustrated in  FIG. 5 , each of the line-like partitions  1220 ,  1221 , and  1222  has a line-like planar shape as viewed in the thickness direction of the TFT substrate  1070  and extends in the extension direction indicated by the arrow AY, like the field concentrated parts  1190 ,  1191 , and  1192 . As illustrated in  FIG. 8 , the line-like partitions  1220 ,  1221 , and  1222  are arranged on the field concentrated parts  1190 ,  1191 , and  1192  respectively. As illustrated in  FIG. 8 , each of the line-like partitions  1220 ,  1221 , and  1222  partitions the liquid crystal layer  1071  in a partitioning direction indicated by the arrow AX. 
     The partition  1081  further includes a line-like partition  1230  and a line-like partition  1231  illustrated in  FIGS. 5 and 8 . The line-like partitions  1230  and  1231  as a second line-like partition are arranged on the line-like electrodes  1160  and  1161  respectively and are substantially parallel to the direction of the alignment film  1094 . The line-like partitions  1230  and  1231  may be formed only in partial regions on the line-like electrodes  1160  and  1161  respectively. As illustrated in  FIG. 5 , each of the line-like partitions  1230  and  1231  has a line-like planar shape as viewed in the thickness direction of the TFT substrate  1070  and extends in the extension direction indicated by the arrow AY, like the field concentrated parts  1200  and  1201 . As illustrated in  FIG. 8 , the line-like partitions  1230  and  1231  are arranged on the field concentrated parts  1200  and  1201  respectively. As illustrated in  FIG. 8 , each of the line-like partitions  1230  and  1231  partitions the liquid crystal layer  1071  in a partitioning direction indicated by the arrow AX. 
     The alignment film  1082  includes a line-like alignment film  1250 , a line-like alignment film  1251 , a line-like alignment film  1252 , a line-like alignment film  1260 , and a line-like alignment film  1261  illustrated in  FIGS. 5 and 8 . As illustrated in  FIGS. 5 and 8 , the line-like alignment films  1250 ,  1251 ,  1252 ,  1260 , and  1261  cover the line-like partitions  1220 ,  1221 ,  1222 ,  1230 , and  1231  respectively. As illustrated in  FIGS. 6, 7 , and  8 , the alignment film  1082  has a surface  1270  contacting the liquid crystal layer  1071 . The surface  1270  of the alignment film  1082  is subjected to alignment process by means of a rubbing or photo-alignment method, for example. Thus, the surface  1270  of the alignment film  1082  has an alignment capability of aligning liquid crystal molecules in the liquid crystal layer  1071  in a particular direction. A direction in which liquid crystal molecules are aligned in the surface  1270  of the alignment film  1082  as a second alignment film agrees with a direction in which liquid crystal molecules are aligned in the upper main surface  1140  of the alignment film  1094  as a first alignment film. The alignment film  1082  is desirably a photo-alignment film subjected to alignment process by means of a photo-alignment method. 
     The partition  1081  illustrated in  FIGS. 5, 6, 7, and 8  desirably has a height of two-thirds or more of a liquid crystal cell gap as a gap between a part of the TFT substrate  1070  other than the partition  1081  and the alignment film  1082 , and the CF substrate  1032 . The reason for this will be described later. 
     1.7 Alignment of Liquid Crystal Molecules 
     When a driving voltage is not applied between the image signal line slit electrode  1124  illustrated in  FIGS. 4, 6, and 8  and the common potential line slit electrode  1125  illustrated in  FIGS. 4, 7, and 8  so a horizontal field does not pass through the liquid crystal layer  1071  illustrated in  FIGS. 6, 7 and 8 , liquid crystal molecules in the liquid crystal layer  1071  are aligned in a pixel direction by the alignment capabilities of the upper main surface  1140  of the alignment film  1094  and the surface  1270  of the alignment film  1082  illustrated in  FIGS. 6, 7, and 8  and a liquid crystal director is in an extinction position. This minimizes the birefringence amount of the liquid crystal layer  1071  to minimize the light transmittance of each pixel region  1060  illustrated in  FIG. 3 . 
     When a driving voltage is applied between the image signal line slit electrode  1124  and the common potential line slit electrode  1125  so a horizontal field passes through the liquid crystal layer  1071 , the liquid crystal molecules in the liquid crystal layer  1071  are rotated from the pixel direction using the horizontal field to rotate the liquid crystal director from the extinction position in a horizontal plane. This increases the birefringence amount of the liquid crystal layer  1071  to increase the light transmittance of each pixel region  1060 . 
     In the liquid crystal display  1000 , during falling time of making a transition from a state in which a horizontal field passes through the liquid crystal layer  1071  to a state in which the horizontal field does not pass through the liquid crystal layer  1071 , return of the liquid crystal director to the extinction position is encouraged not only by the alignment capability of the upper main surface  1140  of the alignment film  1094  but also by the alignment capability of the surface  1270  of the alignment film  1082 , thereby shortening response time during the falling time. Further, this effect can be achieved without necessitating a complicated structure of the pixel electrode. 
     1.8 Replacement with Line-Like Partition Having Forward Tapered Shape 
     If the alignment capability of the surface  1270  of the alignment film  1082  illustrated in  FIGS. 6, 7, and 8  is achieved by employing a photo-alignment system, the line-like partitions  1220 ,  1221 ,  1222 ,  1230 , and  1231  each having a side surface pointed in the extension direction of the TFT substrate  1070  may be replaced, according to an alignment condition, with line-like partitions each having a side surface pointed in a direction tilted from the extension direction of the TFT substrate  1070 . Namely, each of the line-like partitions  1220 ,  1221 ,  1222 ,  1230 , and  1231  may be replaced with a line-like partition having a forward tapered shape with a width that gets smaller with a greater distance from the TFT substrate  1070 . This replacement causes light to easily impinge on a part of the alignment film  1082  covering a side surface of the line-like partition, making it possible to give an alignment capability to the surface  1270  of the alignment film  1082  easily by means of alignment process using an ultraviolet ray. 
     1.9 Replacement with Line-Like Electrode or Line-Like Partition Further Functioning as Light Shield 
     To suppress leakage of light due to instability of the direction of the liquid crystal director occurring near the line-like partitions  1220 ,  1221 ,  1222 ,  1230 , and  1231  illustrated in  FIGS. 5 and 8 , the line-like electrodes  1150 ,  1151 ,  1152 ,  1160 , and  1161  illustrated in  FIGS. 5 and 8  having the same widths as the line-like partitions  1220 ,  1221 ,  1222 ,  1230 , and  1231  respectively may be replaced with line-like electrodes having greater widths than the line-like partitions  1220 ,  1221 ,  1222 ,  1230 , and  1231 . This replacement makes the line-like electrode further function as a light shield to suppress leakage of light. Alternatively, each of the line-like partitions  1220 ,  1221 ,  1222 ,  1230 , and  1231  may be replaced with a line-like partition having a forward tapered shape made of a non-transparent material. This replacement makes the line-like partition further function as a light shield to suppress leakage of light. 
     1.10 Theoretical Analysis of Response Speed During Falling Time 
     As described above, in the liquid crystal display  1000 , return of the liquid crystal director to the extinction position is encouraged during the falling time not only by the alignment capability of the upper main surface  1140  of the alignment film  1094  illustrated in  FIGS. 6, 7, and 8  but also by the alignment capability of the surface  1270  of the alignment film  1082  illustrated in  FIGS. 6, 7, and 8 , thereby increasing response speed during the falling time. In the following description, response speed during the falling time in the absence of a partition such as the partition  1081  and response speed during the falling time in the presence of a partition such as the partition  1081  are theoretically analyzed to show that response time during the falling time in the presence of a partition such as the partition  1081  is about half of response time during the falling time in the absence of a partition such as the partition  1081 . 
     1.11 Theoretical Analysis of Response Speed During Falling Time in the Absence of Partition 
       FIGS. 9 and 10  are schematic views each illustrating a structure model used for theoretically analyzing response speed during the falling time in the absence of a partition. 
       FIGS. 9 and 10  each show a state on an xz plane (xz two-dimensional space) in xyz three-dimensional space in which an xyz three-dimensional orthogonal coordinate system is defined.  FIG. 9  shows a state in which a horizontal field in a direction parallel to the x axis does not pass through a liquid crystal layer.  FIG. 10  shows a state in which a horizontal field in the direction parallel to the x axis passes through the liquid crystal layer. 
     A structure model  1300  illustrated in  FIGS. 9 and 10  is produced by modeling a liquid crystal cell, and includes a lower substrate  1310 , an upper substrate  1311 , and a liquid crystal layer  1312 . The liquid crystal layer  1312  is caught between an upper main surface  1320  of the lower substrate  1310  and a lower main surface  1321  of the upper substrate  1311 . The upper main surface  1320  of the lower substrate  1310  is located at a position where a coordinate value z is 0. The lower main surface  1321  of the upper substrate  1311  is located at a position where a coordinate value z is d. Namely, the liquid crystal layer  1312  has a thickness d. The upper main surface  1320  of the lower substrate  1310  and the lower main surface  1321  of the upper substrate  1311  are each covered with an alignment film not illustrated for aligning liquid crystal molecules in the liquid crystal layer  1312  in a direction parallel to an initial alignment axis parallel to the y axis, namely, an alignment film having an alignment capability of pointing a liquid crystal director for the liquid crystal molecules in the liquid crystal layer  1312  toward a direction parallel to the initial alignment axis. 
     When a horizontal field does not pass through the liquid crystal layer  1312 , the liquid crystal director is pointed in a direction parallel to the initial alignment axis, as illustrated in  FIG. 9 . 
     When the horizontal field passes through the liquid crystal layer  1312 , the liquid crystal director is bound by anchoring energy in the vicinity of the upper main surface  1320  of the lower substrate  1310  and the lower main surface  1321  of the upper substrate  1311  to be pointed in a direction parallel to the initial alignment axis. Meanwhile, in an area other than the vicinity of the upper main surface  1320  of the lower substrate  1310  and the lower main surface  1321  of the upper substrate  1311 , the liquid crystal director is influenced by the horizontal field to be pointed in a direction rotated in a horizontal plane parallel to the xy plane from the direction parallel to the initial alignment axis, as illustrated in  FIG. 10 . An angle of the rotation from the initial alignment axis becomes greater with greater distances from the upper main surface  1320  of the lower substrate  1310  and the lower main surface  1321  of the upper substrate  1311  to become π/2 radian(90°) as a maximum rotation angle at an intermediate position between the upper main surface  1320  of the lower substrate  1310  and the lower main surface  1321  of the upper substrate  1311  at which a coordinate value z is d/2. 
     Falling process is a transient period in which, as application of a driving voltage for generating a horizontal field is stopped in the state shown in  FIG. 10 , a transition is made from the state shown in  FIG. 10  to the state shown in  FIG. 9  to finally produce a stable state shown in  FIG. 9 . 
     In the structure model  1300  illustrated in  FIGS. 9 and 10 , an angle of rotation of the liquid crystal director depends on a position in a direction parallel to the z axis but does not depend on a position in a direction parallel to the x axis and a position in a direction parallel to the y axis. Hence, a one-dimensional equation of motion of the liquid crystal director giving consideration only to a coordinate value z among a coordinate value x, a coordinate value y, and the coordinate value z is used for quantitative analysis of response speed during the falling time. This one-dimensional equation of motion of the liquid crystal director is expressed by a formula (1) using a viscosity constant γ1, a twist elastic modulus K22 of liquid crystal forming the liquid crystal layer  1312 , an electric flux density D, and an angle of rotation θ of the liquid crystal director. 
     
       
         
           
             
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     A driving voltage is not applied in the falling process, so that the second term in the right side of the formula (1) including the electric flux density D is ignorable. Hence, the formula (1) is simplified and written as a formula (2). 
     
       
         
           
             
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     In the state shown in  FIG. 10 , with a twist angle of the liquid crystal director at a position indicated by an optional coordinate value z defined as θzs, the twist angle θzs takes 0 radian if a coordinate value z is 0, the twist angle θzs takes π/2 radian if a coordinate value z is d/2, and the twist angle θzs takes π radian if a coordinate value z is d. 
     Thus, a maximum rotation angle θm of the liquid crystal director at time t and a twist angle θz of the liquid crystal director at a position indicated by a coordinate value z at the time t satisfy a formula (3). 
     
       
         
           
             
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     A formula (4) is obtained by substituting θz in the formula (3) into θ in the formula (2). 
     
       
         
           
             
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     A falling period is a relaxation period in which the liquid crystal director having a maximum twist angle within a range of a coordinate value z from 0 to d is returned to a state of pointing in a direction parallel to the initial alignment axis. Hence, the falling period can be determined by giving consideration only to a position where a coordinate value z is d/2. 
     The element θz in the left side of the formula (3) becomes θm. Thus, a differential equation in a formula (5) is obtained by replacing θz in the left side of the formula (3) with θm and substituting d/2 into z in the formula (3). 
     
       
         
           
             
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                 5 
               
               ] 
             
              
             
                 
             
           
         
       
       
         
           
             
               
                 
                   
                     
                       θ 
                        
                       
                           
                       
                        
                       m 
                     
                     dt 
                   
                   = 
                   
                     
                       - 
                       K 
                     
                      
                     
                         
                     
                      
                     22 
                      
                     
                       
                         π 
                         2 
                       
                       
                         γ1 
                         * 
                         
                           d 
                           2 
                         
                       
                     
                     * 
                     θ 
                      
                     
                         
                     
                      
                     m 
                   
                 
               
               
                 
                   ( 
                   5 
                   ) 
                 
               
             
           
         
       
     
     A formula (6) is obtained by solving the differential equation in the formula (5). 
     
       
         
           
             
               [ 
               
                 Formula 
                  
                 
                     
                 
                  
                 6 
               
               ] 
             
              
             
                 
             
           
         
       
       
         
           
             
               
                 
                   
                     
                       θ 
                        
                       
                           
                       
                        
                       m 
                     
                     dt 
                   
                   = 
                   
                     
                       
                         
                           - 
                           K 
                         
                          
                         
                             
                         
                          
                         22 
                         * 
                         θ 
                          
                         
                             
                         
                          
                         m 
                         * 
                         
                           π 
                           2 
                         
                       
                       
                         γ1 
                         * 
                         
                           d 
                           2 
                         
                       
                     
                     * 
                     t 
                   
                 
               
               
                 
                   ( 
                   6 
                   ) 
                 
               
             
           
         
       
     
     Like a formula used for obtaining time of discharging a charged capacitor, a falling response formula for obtaining the falling period is given by a formula (7) using an initial condition defining that the maximum rotation angle θm takes θm(0) when the time t is 0. 
     
       
         
           
             
               [ 
               
                 Formula 
                  
                 
                     
                 
                  
                 7 
               
               ] 
             
              
             
                 
             
           
         
       
       
         
           
             
               
                 
                   
                     θ 
                      
                     
                       ( 
                       t 
                       ) 
                     
                   
                   = 
                   
                     θ 
                      
                     
                         
                     
                      
                     
                       m 
                        
                       
                         ( 
                         0 
                         ) 
                       
                     
                      
                     
                       e 
                       
                         t 
                         
                           time 
                            
                           
                               
                           
                            
                           constant 
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   7 
                   ) 
                 
               
             
           
         
       
     
     The time constant in the formula (7) is defined as (−K22*π 2 )/(γ1*d 2 ). Hence, a falling response formula in the absence of a partition is given by a formula (8) and a formula (9). 
     
       
         
           
             
               
                 
                   
                     [ 
                     
                       Formula 
                        
                       
                           
                       
                        
                       8 
                     
                     ] 
                   
                    
                   
                       
                   
                 
               
               
                 
                     
                 
               
             
             
               
                 
                   
                     θ 
                      
                     
                       ( 
                       t 
                       ) 
                     
                   
                   = 
                   
                     θ 
                      
                     
                         
                     
                      
                     
                       m 
                        
                       
                         ( 
                         0 
                         ) 
                       
                     
                      
                     
                       e 
                       
                         
                           - 
                           t 
                         
                         τ 
                       
                     
                   
                 
               
               
                 
                   ( 
                   8 
                   ) 
                 
               
             
             
               
                 
                   
                     [ 
                     
                       Formula 
                        
                       
                           
                       
                        
                       9 
                     
                     ] 
                   
                    
                   
                       
                   
                 
               
               
                 
                     
                 
               
             
             
               
                 
                   τ 
                   = 
                   
                     
                       γ1 
                       * 
                       
                         d 
                         2 
                       
                     
                     
                       K 
                        
                       
                           
                       
                        
                       22 
                       * 
                       π 
                     
                   
                 
               
               
                 
                   ( 
                   9 
                   ) 
                 
               
             
           
         
       
     
     1.12 Theoretical Analysis of Response Speed During Falling Time in the Presence of Partition 
       FIGS. 11 and 12  are schematic views each illustrating a structure model used for theoretically analyzing response speed during the falling time in the presence of a partition. 
       FIGS. 11 and 12  each show a state on an xz plane (xz two-dimensional space) in xyz three-dimensional space in which an xyz three-dimensional orthogonal coordinate system is defined.  FIG. 11  shows a state in which a horizontal field in a direction parallel to the x axis does not pass through a liquid crystal layer.  FIG. 12  shows a state in which a horizontal field in the direction parallel to the x axis passes through the liquid crystal layer. 
     A structure model  1400  illustrated in  FIGS. 11 and 12  is produced by modeling a minimum constitutional unit of a liquid crystal cell, and includes a lower substrate  1410 , an upper substrate  1411 , a left partition  1412 , a right partition  1413 , and a liquid crystal layer  1414 . The liquid crystal layer  1414  is caught between an upper main surface  1420  of the lower substrate  1410  and a lower main surface  1421  of the upper substrate  1411 , and between a right main surface  1422  of the left partition  1412  and a left main surface  1423  of the right partition  1413 . The upper main surface  1420  of the lower substrate  1410  is located at a position where a coordinate value z is 0. The lower main surface  1421  of the upper substrate  1411  is located at a position where a coordinate value z is d. The right main surface  1422  of the left partition  1412  is located at a position where a coordinate value x is 0. The left main surface  1423  of the right partition  1413  is located at a position where a coordinate value x is 1. Namely, the liquid crystal layer  1414  has a thickness d and a width 1. The upper main surface  1420  of the lower substrate  1410 , the lower main surface  1421  of the upper substrate  1411 , the right main surface  1422  of the left partition  1412 , and the left main surface  1423  of the right partition  1413  are each covered with an alignment film not illustrated for aligning liquid crystal molecules in the liquid crystal layer  1414  in a direction parallel to an initial alignment axis parallel to the y axis, namely, an alignment film having an alignment capability of pointing a liquid crystal director for the liquid crystal molecules in the liquid crystal layer  1414  toward a direction parallel to the initial alignment axis. 
     When a horizontal field does not pass through the liquid crystal layer  1414 , the liquid crystal director is pointed in a direction parallel to the initial alignment axis, as illustrated in  FIG. 11 . 
     When the horizontal field passes through the liquid crystal layer  1414 , the liquid crystal director is bound by anchoring energy in the vicinity of the upper main surface  1420  of the lower substrate  1410 , the lower main surface  1421  of the upper substrate  1411 , the right main surface  1422  of the left partition  1412 , and the left main surface  1423  of the right partition  1413  to be pointed in a direction parallel to the initial alignment axis, as illustrated in  FIG. 12 . Meanwhile, in an area other than the vicinity of the upper main surface  1420  of the lower substrate  1410 , the lower main surface  1421  of the upper substrate  1411 , the right main surface  1422  of the left partition  1412 , and the left main surface  1423  of the right partition  1413 , the liquid crystal director is influenced by the horizontal field to be pointed in a direction rotated in a horizontal plane parallel to the xy plane from the direction parallel to the initial alignment axis, as illustrated in  FIG. 12 . An angle of the rotation from the initial alignment axis becomes greater with greater distances from the upper main surface  1420  of the lower substrate  1410 , the lower main surface  1421  of the upper substrate  1411 , the right main surface  1422  of the left partition  1412 , and the left main surface  1423  of the right partition  1413  to become π/2 radian (90°) as a maximum at an intermediate position between the upper main surface  1420  of the lower substrate  1410  and the lower main surface  1421  of the upper substrate  1411  and at an intermediate position between the right main surface  1422  of the left partition  1412  and the left main surface  1423  of the right partition  1413  at which a coordinate value x is ½ and a coordinate value z is d/2. 
     In the structure model  1400  illustrated in  FIGS. 11 and 12 , an angle of rotation of the liquid crystal director depends on a position in a direction parallel to the x axis and on a position in a direction parallel to the z axis but does not depend on a position in a direction parallel to the y axis. Hence, a two-dimensional equation of motion of the liquid crystal director giving consideration only to a coordinate value x and a coordinate value z among the coordinate value x, a coordinate value y, and the coordinate value z is used for quantitative analysis of response speed during the falling time. This two-dimensional equation of motion of the liquid crystal director is obtained by modifying the one-directional equation of motion of the liquid crystal director expressed by the formula (2), and is expressed by a formula (10). 
     
       
         
           
             
               [ 
               
                 Formula 
                  
                 
                     
                 
                  
                 10 
               
               ] 
             
              
             
                 
             
           
         
       
       
         
           
             
               
                 
                   
                     γ1 
                      
                     
                       
                         ∂ 
                         
                           θ 
                            
                           
                             ( 
                             
                               x 
                               , 
                               z 
                             
                             ) 
                           
                         
                       
                       
                         ∂ 
                         t 
                       
                     
                   
                   = 
                   
                     
                       K 
                        
                       
                           
                       
                        
                       11 
                        
                       
                         
                           
                             
                               ∂ 
                               2 
                             
                              
                             θ 
                           
                            
                           
                               
                           
                            
                           x 
                         
                         
                           ∂ 
                           
                             x 
                             2 
                           
                         
                       
                     
                     + 
                     
                       K 
                        
                       
                           
                       
                        
                       22 
                        
                       
                         
                           
                             
                               ∂ 
                               2 
                             
                              
                             θ 
                           
                            
                           
                               
                           
                            
                           z 
                         
                         
                           ∂ 
                           
                             z 
                             2 
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   10 
                   ) 
                 
               
             
           
         
       
     
     A maximum rotation angle θm of the liquid crystal director at time t, a twist angle θx of the liquid crystal director at a position indicated by a coordinate value x at the time t, and a twist angle θz of the liquid crystal director at a position indicated by a coordinate value z at the time t satisfy a formula (11) and a formula (12). 
     
       
         
           
             
               
                 
                   
                     [ 
                     
                       Formula 
                        
                       
                           
                       
                        
                       11 
                     
                     ] 
                   
                    
                   
                       
                   
                 
               
               
                 
                     
                 
               
             
             
               
                 
                   
                     θ 
                      
                     
                         
                     
                      
                     x 
                   
                   = 
                   
                     θ 
                      
                     
                         
                     
                      
                     m 
                     * 
                     
                       sin 
                        
                       
                         ( 
                         
                           
                             π 
                             l 
                           
                           * 
                           x 
                         
                         ) 
                       
                     
                   
                 
               
               
                 
                   ( 
                   11 
                   ) 
                 
               
             
             
               
                 
                   
                     [ 
                     
                       Formula 
                        
                       
                           
                       
                        
                       12 
                     
                     ] 
                   
                    
                   
                       
                   
                 
               
               
                 
                     
                 
               
             
             
               
                 
                   
                     θ 
                      
                     
                         
                     
                      
                     z 
                   
                   = 
                   
                     θ 
                      
                     
                         
                     
                      
                     m 
                     * 
                     
                       sin 
                        
                       
                         ( 
                         
                           
                             π 
                             d 
                           
                           * 
                           z 
                         
                         ) 
                       
                     
                   
                 
               
               
                 
                   ( 
                   12 
                   ) 
                 
               
             
           
         
       
     
     A formula (13) is obtained by respectively substituting θx in the formula (11) and θz in the formula (12) into θx and θz in the formula (10). 
     
       
         
           
             
               [ 
               
                 Formula 
                  
                 
                     
                 
                  
                 13 
               
               ] 
             
              
             
                 
             
           
         
       
       
         
           
             
               
                 
                   
                     
                       γ1 
                       * 
                       
                         ∂ 
                         
                           θ 
                            
                           
                             ( 
                             
                               x 
                               , 
                               z 
                             
                             ) 
                           
                         
                       
                     
                     
                       ∂ 
                       t 
                     
                   
                   = 
                   
                     
                       K 
                        
                       
                           
                       
                        
                       11 
                       * 
                       
                         
                           π 
                           2 
                         
                         
                           l 
                           2 
                         
                       
                       * 
                       θ 
                        
                       
                           
                       
                        
                       m 
                       * 
                       
                         sin 
                          
                         
                           ( 
                           
                             
                               π 
                               l 
                             
                             * 
                             x 
                           
                           ) 
                         
                       
                     
                     + 
                     
                       K 
                        
                       
                           
                       
                        
                       22 
                       * 
                       
                         
                           π 
                           2 
                         
                         
                           d 
                           2 
                         
                       
                       * 
                       θ 
                        
                       
                           
                       
                        
                       m 
                       * 
                       
                         sin 
                          
                         
                           ( 
                           
                             
                               π 
                               d 
                             
                             * 
                             z 
                           
                           ) 
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   13 
                   ) 
                 
               
             
           
         
       
     
     A falling period is relaxation time in which the liquid crystal director having a maximum twist angle within a range of a coordinate value x from 0 to 1 and a range of a coordinate value z from 0 to d is returned to a state of pointing in a direction parallel to the initial alignment axis. Hence, the falling period can be determined by giving consideration only to a position where a coordinate value x is ½ and a coordinate value z is d/2. 
     A formula (14) is obtained by respectively substituting ½ and d/2 into x and z in the formula (13). 
     
       
         
           
             
               [ 
               
                 Formula 
                  
                 
                     
                 
                  
                 14 
               
               ] 
             
              
             
                 
             
           
         
       
       
         
           
             
               
                 
                   
                     
                       θ 
                        
                       
                         ( 
                         
                           x 
                           , 
                           z 
                         
                         ) 
                       
                     
                     dt 
                   
                   = 
                   
                     
                       
                         θ 
                          
                         
                             
                         
                          
                         m 
                         * 
                         
                           π 
                           2 
                         
                       
                       γ1 
                     
                     * 
                     
                       ( 
                       
                         
                           
                             K 
                              
                             
                                 
                             
                              
                             11 
                           
                           
                             l 
                             2 
                           
                         
                         + 
                         
                           
                             K 
                              
                             
                                 
                             
                              
                             22 
                           
                           
                             d 
                             2 
                           
                         
                       
                       ) 
                     
                   
                 
               
               
                 
                   ( 
                   14 
                   ) 
                 
               
             
           
         
       
     
     Like in the case in the absence of a partition, a falling response formula for obtaining the falling period is given by a formula (15) and a formula (16). 
     
       
         
           
             
               
                 
                   
                     [ 
                     
                       Formula 
                        
                       
                           
                       
                        
                       15 
                     
                     ] 
                   
                    
                   
                       
                   
                 
               
               
                 
                     
                 
               
             
             
               
                 
                   
                     θ 
                      
                     
                       ( 
                       t 
                       ) 
                     
                   
                   = 
                   
                     
                       θ 
                        
                       
                         ( 
                         0 
                         ) 
                       
                     
                      
                     
                       e 
                       
                         
                           - 
                           t 
                         
                         τ 
                       
                     
                   
                 
               
               
                 
                   ( 
                   15 
                   ) 
                 
               
             
             
               
                 
                   
                     [ 
                     
                       Formula 
                        
                       
                           
                       
                        
                       16 
                     
                     ] 
                   
                    
                   
                       
                   
                 
               
               
                 
                     
                 
               
             
             
               
                 
                   τ 
                   = 
                   
                     γ1 
                     
                       
                         π 
                         2 
                       
                       * 
                       
                         ( 
                         
                           
                             
                               K 
                                
                               
                                   
                               
                                
                               11 
                             
                             
                               l 
                               2 
                             
                           
                           + 
                           
                             
                               K 
                                
                               
                                   
                               
                                
                               22 
                             
                             
                               d 
                               2 
                             
                           
                         
                         ) 
                       
                     
                   
                 
               
               
                 
                   ( 
                   16 
                   ) 
                 
               
             
           
         
       
     
     In liquid crystal forming a liquid crystal layer provided in a liquid crystal display of the horizontal field system, the splay elastic modulus K11 is generally about twice the twist elastic modulus K22. 
     On the assumption that the splay elastic modulus K11 is twice the twist elastic modulus K22 and the width 1 of the liquid crystal layer  1414  is equal to the thickness d of the liquid crystal layer  1414 , a time constant T is expressed by a formula (17). 
     
       
         
           
             
               [ 
               
                 Formula 
                  
                 
                     
                 
                  
                 17 
               
               ] 
             
              
             
                 
             
           
         
       
       
         
           
             
               
                 
                   τ 
                   = 
                   
                     
                       γ1 
                       
                         
                           π 
                           2 
                         
                         * 
                         
                           ( 
                           
                             
                               
                                 K 
                                  
                                 
                                     
                                 
                                  
                                 11 
                               
                               
                                 l 
                                 2 
                               
                             
                             + 
                             
                               
                                 K 
                                  
                                 
                                     
                                 
                                  
                                 22 
                               
                               
                                 d 
                                 2 
                               
                             
                           
                           ) 
                         
                       
                     
                     = 
                     
                       
                         γ1 
                         
                           
                             π 
                             2 
                           
                           * 
                           
                             ( 
                             
                               
                                 
                                   2 
                                   * 
                                   K 
                                    
                                   
                                       
                                   
                                    
                                   22 
                                 
                                 
                                   d 
                                   2 
                                 
                               
                               + 
                               
                                 
                                   K 
                                    
                                   
                                       
                                   
                                    
                                   22 
                                 
                                 
                                   d 
                                   2 
                                 
                               
                             
                             ) 
                           
                         
                       
                       = 
                       
                         
                           γ1 
                           
                             
                               π 
                               2 
                             
                             * 
                             
                               ( 
                               
                                 
                                   K 
                                    
                                   
                                       
                                   
                                    
                                   22 
                                 
                                 
                                   d 
                                   2 
                                 
                               
                               ) 
                             
                           
                         
                         * 
                         
                           1 
                           3 
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   17 
                   ) 
                 
               
             
           
         
       
     
     1.13 Comparison Between the Absence of Partition and the Presence of Partition 
     The time constant τ in the absence of a partition is expressed by the formula (9). Under the foregoing assumption, the time constant t in the presence of a partition is expressed by the formula (17). 
     Thus, if the foregoing assumption is adopted, a ratio of the falling period in the presence of a partition to the falling period in the absence of a partition is expressed by a formula (18). 
     
       
         
           
             
               [ 
               
                 Formula 
                  
                 
                     
                 
                  
                 18 
               
               ] 
             
              
             
                 
             
           
         
       
       
         
           
             
               
                 
                   
                     
                       e 
                       
                         ( 
                         
                           1 
                           3 
                         
                         ) 
                       
                     
                     e 
                   
                   ≈ 
                   
                     1 
                     2 
                   
                 
               
               
                 
                   ( 
                   18 
                   ) 
                 
               
             
           
         
       
     
     As understood from the foregoing ratio, response time during the falling time in the presence of a partition is about half of response time during the falling time in the absence of a partition. 
     If the splay elastic modulus K11 is not twice the twist elastic modulus K22, the foregoing ratio changes from ½. This ratio also changes from ½ if the width 1 of the liquid crystal layer  1414  is not equal to the thickness d of the liquid crystal layer  1414 . In such cases, however, response time during the falling time in the presence of a partition is still shorter than response time during the falling time in the absence of a partition. 
     In the foregoing analysis, the maximum rotation angle is described as π/2 radian (90°) corresponding to a theoretical upper limit. In an actual liquid crystal display of the horizontal field system, however, a maximum rotation angle for display of white is about π/4 radian (45°). Thus, in the actual liquid crystal display of the horizontal field system, the foregoing ratio may take a value different from ½. In such a case, however, response during the falling time in the presence of a partition is still shorter than response time during the falling time in the absence of a partition. 
     1.14 Analysis of Response Speed During Falling Time by Simulation 
     In the following description, response speed during the falling time in the absence of a partition such as the partition  1081  and response speed during the falling time in the presence of a partition such as the partition  1081  are analyzed by simulation to show that response time during the falling time in the presence of a partition such as the partition  1081  is about one-third of response time during the falling time in the absence of a partition such as the partition  1081 . 
     A used simulator is LCDMaster 2D (Ver. 8.5.2) available from SHINTECH, Inc. Table 1 shows the physical property values of a liquid crystal material MS-5355XX-K forming a liquid crystal layer in a structure model used in the simulation. Table 2 shows common parameters common to structure models used in the simulation. The structure models used in the simulation were simplified to a maximum within a range in which the appropriateness of the structure models can be guaranteed. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Wavelength 
                   
                   
               
               
                   
                 (nm) 
                 Ordinary light (no) 
                 Extraordinary light (ne) 
               
               
                   
               
             
            
               
                 Refractive index 
                 450 
                 1.504 
                 1.638 
               
               
                   
                 550 
                 1.492 
                 1.614 
               
               
                   
                 650 
                 1.486 
                 1.602 
               
            
           
           
               
               
               
            
               
                 Relative 
                 εp 
                 7.5 
               
               
                 permittivity 
                 εS 
                 2.9 
               
               
                 Elastic constant 
                 K11 
                 14.6 
               
               
                 (pN) 
                 K22 
                 7.3 
               
               
                   
                 K33 
                 19.1 
               
               
                 Viscosity 
                 γ1 
                 0.099 
               
               
                 constant (Pa · s) 
                   
                   
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
             
               
                   
                 TABLE 2 
               
               
                   
                   
               
             
            
               
                   
                 Cell gap 
                 3.0 μm 
               
               
                   
                 Lower substrate rubbing angle 
                 83° 
               
               
                   
                 Lower polarizing axis 
                 83° - (retardation) 
               
               
                   
                 Alignment film 
                 Independent of model 
               
               
                   
                 Backlight source 
                 Light source C 
               
               
                   
                   
               
            
           
         
       
     
     1.15 Analysis of Response Speed During Falling Time by Simulation in the Absence of Partition 
       FIG. 13  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the absence of a partition. 
     A structure model  1500  illustrated in  FIG. 13  is produced by modeling a minimum recurring unit of a liquid crystal cell of the in-plane switching (IPS) system, and includes a lower substrate  1510 , an upper counter substrate  1511 , and a liquid crystal layer  1512 . The lower substrate  1510  includes a lower glass substrate  1520 , an organic planarizing film  1521 , an image signal line slit electrode  1522 , and a common potential line slit electrode  1523 . The image signal line slit electrode  1522  includes a line-like electrode  1530 . The common potential line slit electrode  1523  includes a line-like electrode  1540  and a line-like electrode  1541 . 
     The liquid crystal material MS-5355XX-K is poured in between an upper main surface  1550  of the lower substrate  1510  and a lower main surface  1551  of the upper counter substrate  1511  to form the liquid crystal layer  1512  made of the liquid crystal material MS-5355XX-K. An alignment film not illustrated covering the upper main surface  1550  of the lower substrate  1510  is subjected to alignment process for aligning liquid crystal molecules in the liquid crystal layer  1512  in a first direction. An alignment film not illustrated covering the lower main surface  1551  of the upper counter substrate  1511  is subjected to alignment process for aligning the liquid crystal molecules in the liquid crystal layer  1512  in a second direction perpendicular to the first direction. Each of the line-like electrodes  1530 ,  1540 , and  1541  has a width of 1.5 μm. A gap between two adjacent ones of the line-like electrodes  1530 ,  1540 , and  1541  is 1.5 μm. A liquid crystal cell gap, which is a distance from the upper main surface  1550  of the lower substrate  1510  to the lower main surface  1551  of the upper counter substrate  1511 , is 3.0 
     1.16 Analysis of Response Speed During Falling Time by Simulation in the Presence of Partition 
       FIG. 14  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the presence of a partition. 
     A structure model  1600  illustrated in  FIG. 14  is produced by modeling a minimum recurring unit a liquid crystal cell of the IPS system to which partition is added, and includes a lower substrate  1610 , an upper counter substrate  1611 , and a liquid crystal layer  1612 . The lower substrate  1610  includes a lower glass substrate  1620 , an organic planarizing film  1621 , an image signal line slit electrode  1622 , a common potential line slit electrode  1623 , and a partition  1624 . The image signal line slit electrode  1622  includes a line-like electrode  1630 . The common potential line slit electrode  1623  includes a line-like electrode  1640  and a line-like electrode  1641 . The partition  1624  includes a line-like partition  1650 , a line-like partition  1660 , and a line-like partition  1661 . 
     The liquid crystal material MS-5355XX-K is poured in between an upper main surface  1670  of the lower substrate  1610  and a lower main surface  1671  of the upper counter substrate  1611  to form the liquid crystal layer  1612  made of the liquid crystal material MS-5355XX-K. The upper main surface  1670  of the lower substrate  1610  is subjected to alignment process for aligning liquid crystal molecules in the liquid crystal layer  1612  in a first direction. The lower main surface  1671  of the upper counter substrate  1611  is subjected to alignment process for aligning the liquid crystal molecules in the liquid crystal layer  1612  in a second direction perpendicular to the first direction. Each of the line-like electrodes  1630 ,  1640 , and  1641  has a width of 1.5 μm. A gap between two adjacent ones of the line-like electrodes  1630 ,  1640 , and  1641  is 1.5 μm. A liquid crystal cell gap is 3.0 μm. 
     The line-like partitions  1650 ,  1660 , and  1661  are arranged on the line-like electrodes  1630 ,  1640 , and  1641  respectively. 
     Each of the line-like partitions  1650 ,  1660 , and  1661  has a height of 3.0 μm corresponding to the liquid crystal cell gap to partition the liquid crystal layer  1612  completely in a direction parallel to an extension direction of the lower substrate  1610 . 
     In the structure model  1600 , to prevent reduction in liquid crystal caused by addition of the partition  1624  from making disturbance in a result of the simulation, the width of each of the line-like partitions  1650 ,  1660 , and  1661  is set at a lower limit of 0.16 μm. 
     1.17 Comparison Between the Absence of Partition and the Presence of Partition 
       FIG. 15  is a graph showing response curves obtained by evaluating response characteristics using the structure model in the absence of a partition illustrated in  FIG. 13  and the structure model in the presence of a partition illustrated in  FIG. 14 . 
     For evaluation of the response characteristics, a driving signal at a frequency of 30 Hz having an optimum voltage was applied in two cycles in a period from a point in time when passed time is 0 ms to a point in time when passed time is 66.67 ms to display white having maximum brightness. Next, in a period from the point in time when passed time is 66.67 ms to a point in time when passed time is 100 ms, 0 V was applied. Change in brightness transmittance with passed time was evaluated in a period from the point in time when passed time is 0 ms to the point in time when passed time is 100 ms. 
     As shown in  FIG. 15 , rising and falling of a response curve corresponding to use of the structure model  1600  in the presence of the partition  1624  illustrated in  FIG. 14  are respectively steeper than rising and falling of a response curve corresponding to use of the structure model  1500  in the absence of a partition illustrated in  FIG. 13 . 
     A period from a point in time when application of a driving signal was started to a point in time when brightness transmittance has increased to 90% of a maximum is defined as a rising period. A period from a point in time when application of the driving signal was finished to a point in time when brightness transmittance has decreased to 10% of the maximum is defined as a falling period. In this case, as a result of use of the structure model  1500  illustrated in  FIG. 13  in the absence of a partition and use of the structure model  1600  illustrated in  FIG. 14  in the presence of the partition  1624 , the rising period and the falling period in each of these uses are determined as shown in Table 3. 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 First embodiment 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Electrode 
                 Gap between 
                 Cell 
                 Rising 
                 Falling 
                 Brightness 
               
               
                 System 
                 width 
                 electrodes 
                 gap 
                 period 
                 period 
                 transmittance 
               
               
                   
               
               
                 Without partition 
                 1.5 μm 
                 1.5 μm 
                 3.0 μm 
                 12.2 ms 
                 12.4 ms 
                 77.0% 
               
               
                 With partition 
                 1.5 μm 
                 1.5 μm 
                 3.0 μm 
                  6.4 ms 
                  4.0 ms 
                 46.8% 
               
               
                   
               
            
           
         
       
     
     As understood from Table 3, the falling period determined by the use of the structure model  1600  illustrated in  FIG. 14  in the presence of the partition  1624  is about one-third of the falling period determined by the use of the structure model  1500  illustrated in  FIG. 13  in the absence of a partition. 
     1.18 Partition Height 
     In the structure model  1600  illustrated in  FIG. 14 , the partition  1624  has a height of 3.0 μm corresponding to the liquid crystal cell gap, so that the partition  1624  extends from the image signal line slit electrode  1622  and the common potential line slit electrode  1623  to reach as far as the upper counter substrate  1611 . However, extension of the partition  1624  from the image signal line slit electrode  1622  and the common potential line slit electrode  1623  to the upper counter substrate  1611  may cause difficulty in pouring a liquid crystal material in between the upper main surface  1670  of the lower substrate  1610  and the lower main surface  1671  of the upper counter substrate  1611 . 
     The partition  1624  is provided to fix the direction of the liquid crystal director by means of anchoring energy. In the vicinity of the lower main surface  1671  of the upper counter substrate  1611 , however, the lower main surface  1671  of the upper counter substrate  1611  functions to fix the direction of the liquid crystal director. Hence, the partition  1624  is not required to reach as far as the upper counter substrate  1611 , so that replacing the partition  1624  with a partition having a smaller height than the liquid crystal cell gap is considered to be allowable. 
     To demonstrate the applicability of replacement of the partition  1624  with a partition having a smaller height than the liquid crystal cell gap, analysis by simulation was conducted. 
       FIG. 16  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the presence of a partition such as the partition  1081 . 
     A structure model  1700  illustrated in  FIG. 16  is produced by modeling a minimum recurring unit of a liquid crystal cell of the IPS system to which partition is added, and includes a lower substrate  1710 , an upper counter substrate  1711 , and a liquid crystal layer  1712 . The lower substrate  1710  includes a lower glass substrate  1720 , an organic planarizing film  1721 , an image signal line slit electrode  1722 , a common potential line slit electrode  1723 , and a partition  1724 . The image signal line slit electrode  1722  includes a line-like electrode  1730 . The common potential line slit electrode  1723  includes a line-like electrode  1740  and a line-like electrode  1741 . The partition  1724  includes a line-like partition  1750 , a line-like partition  1760 , and a line-like partition  1761 . The structure model  1700  illustrated in  FIG. 16  is similar to the structure model  1600  illustrated in  FIG. 14 , except that the partition  1724  does not reach as far as the upper counter substrate  1711 . 
       FIG. 17  is a graph showing change in the rising period and the falling period resulting from the height of a partition determined by evaluating response characteristics using the structure model illustrated in  FIG. 16 . 
     As shown in  FIG. 17 , the rising period and the falling period tend to be reduced with increase in the height of the partition  1724 , but are practically saturated in a range where the height of the partition  1724  is 2 μm or more. This shows that the partition  1724  is not required to reach as far as the upper counter substrate  1711  and the effect of shortening the rising period and the falling period can be achieved sufficiently with the partition  1724  having a height of two-thirds or more of the liquid crystal cell gap. 
     2. Second Embodiment 
     2.1 Main Difference Between First Embodiment and Second Embodiment 
     A second embodiment relates to a liquid crystal display of the horizontal field system. 
     The first embodiment and the second embodiment differ from each other mainly in the following. In the first embodiment, the image signal line slit electrode  1124  and the common potential line slit electrode  1125  form a pixel electrode, and the common potential line slit electrode  1125  is arranged in the same layer as the image signal line slit electrode  1124 , as illustrated in  FIG. 8 . In the second embodiment, an image signal line slit electrode and a common potential line lower electrode form a pixel electrode, the common potential line lower electrode is arranged in a different layer from the image signal line slit electrode, and a generated horizontal field becomes a fringe field. Structures or modifications thereof employed in liquid crystal displays of the other embodiments may also be employed in the liquid crystal display of the second embodiment within a range in which structures resulting in the foregoing main difference can be employed without any interference. 
     2.2 Liquid Crystal Display, Liquid Crystal Panel, and Display Region 
     The schematic view of  FIG. 1  is also a perspective view illustrating the liquid crystal display of the second embodiment. The schematic view of  FIG. 2  is also a sectional view illustrating a section of a liquid crystal panel provided in the liquid crystal display of the second embodiment. The schematic view of  FIG. 3  is also a plan view illustrating a TFT substrate, a printed board, and an integrated circuit chip provided in the liquid crystal display of the second embodiment. 
     2.3 TFT Substrate 
     The schematic view of  FIG. 18  is a plan view illustrating planar arrangement of a line, an electrode, and a semiconductor channel layer provided in the liquid crystal display of the second embodiment. The schematic view of  FIG. 19  is a plan view illustrating planar arrangement of an organic planarizing film, a partition, and an alignment film provided in the liquid crystal display of the second embodiment.  FIGS. 20, 21, and 22  are sectional views each illustrating sections of the TFT substrate and a liquid crystal layer provided in the liquid crystal display of the second embodiment. 
       FIG. 20  illustrates a section taken at a position along a cutting line A-A′ in  FIGS. 18 and 19 .  FIG. 21  illustrates a section taken at a position along a cutting line B-B′ in  FIGS. 18 and 19 .  FIG. 22  illustrates a section taken at a position along a cutting line C-C′ in  FIGS. 18 and 19 . 
       FIGS. 18, 19, 20, 21, and 22  illustrate the pixel region  1060  illustrated in  FIG. 3 . 
     A TFT substrate  2070  illustrated in  FIGS. 18, 19, 20, 21, and 22  becomes the TFT substrate  1030  illustrated in  FIGS. 1, 2, and 3 . A liquid crystal layer  2071  illustrated in  FIGS. 20, 21, and 22  becomes the liquid crystal layer  1031  illustrated in  FIG. 2 . 
       FIG. 18  illustrates an image signal line  2100 , a scanning line  2110 , a common potential line  2111 , a scanning line electrode  2120 , a semiconductor channel layer  2121 , an image signal line electrode  2122 , an image signal line electrode  2123 , an image signal line slit electrode  2124 , a common potential line lower electrode  2125 , an image signal line through hole group  2126 , and a common potential line through hole  2127  provided in the TFT substrate  2070 . 
       FIG. 19  illustrates an organic planarizing film  2093 , a partition  2081 , and an alignment film  2082  provided in the TFT substrate  2070 . 
       FIG. 20  illustrates a glass substrate  2090 , a scanning line insulating film  2091 , an interlayer insulating film  2092 , the organic planarizing film  2093 , an alignment film  2094 , the common potential line  2111 , the scanning line electrode  2120 , the semiconductor channel layer  2121 , the image signal line electrode  2122 , the image signal line electrode  2123 , the image signal line slit electrode  2124 , the common potential line lower electrode  2125 , the image signal line through hole group  2126 , the common potential line through hole  2127 , the partition  2081 , and the alignment film  2082  provided in the TFT substrate  2070 . 
       FIG. 21  illustrates the glass substrate  2090 , the scanning line insulating film  2091 , the interlayer insulating film  2092 , the organic planarizing film  2093 , the alignment film  2094 , the image signal line  2100 , the scanning line  2110 , the common potential line  2111 , the common potential line lower electrode  2125 , the partition  2081 , and the alignment film  2082  provided in the TFT substrate  2070 . 
       FIG. 22  illustrates the glass substrate  2090 , the scanning line insulating film  2091 , the interlayer insulating film  2092 , the organic planarizing film  2093 , the image signal line slit electrode  2124 , the common potential line lower electrode  2125 , the alignment film  2094 , the partition  2081 , and the alignment film  2082  provided in the TFT substrate  2070 . 
     The image signal line  2100  is at each pixel-regions-array  1051  illustrated in  FIG. 3 . The scanning line  2110  and the common potential line  2111  are at each pixel-regions-array  1050  illustrated in  FIG. 3 . The scanning line electrode  2120 , the semiconductor channel layer  2121 , the image signal line electrode  2122 , the image signal line electrode  2123 , the image signal line slit electrode  2124 , the common potential line lower electrode  2125 , the image signal line through hole group  2126 , the common potential line through hole  2127 , the partition  2081 , and the alignment film  2082  are at each pixel region  1060  illustrated in  FIG. 3 . 
     The scanning line insulating film  2091 , the scanning line electrode  2120 , the semiconductor channel layer  2121 , the image signal line electrode  2122 , and the image signal line electrode  2123  form a TFT. The image signal line slit electrode  2124  and the common potential line lower electrode  2125  form a pixel electrode. 
     The glass substrate  2090 , the scanning line  2110 , the common potential line  2111 , and the scanning line electrode  2120  respectively correspond to the glass substrate  1090 , the scanning line  1110 , the common potential  1111 , and the scanning line electrode  1120  of the first embodiment. 
     The scanning line insulating film  2091  is stacked on the scanning line  2110 , the common potential line  2111 , and the scanning line electrode  2120  and arranged over an upper main surface  2130  of the glass substrate  2090  as illustrated in  FIGS. 20, 21, and 22 , and extends across a plurality of pixel regions forming the display region  1040  illustrated in  FIG. 3 . The scanning line insulating film  2091  separates the scanning line  2110 , the common potential line  2111 , and the scanning line electrode  2120  under the scanning line insulating film  2091  in the thickness direction of the TFT substrate  2070  from the image signal line  2100 , the semiconductor channel layer  2121 , the image signal line electrode  2122 , and the image signal line electrode  2123  over the scanning line insulating film  2091 , thereby insulating the scanning line  2110 , the common potential line  2111 , and the scanning line electrode  2120  from the image signal line  2100 , the semiconductor channel layer  2121 , the image signal line electrode  2122 , and the image signal line electrode  2123 . 
     The image signal line  2100  is stacked on the scanning line insulating film  2091  and arranged over the upper main surface  2130  of the glass substrate  2090  as illustrated in  FIG. 21 , and extends across a plurality of pixel regions forming each pixel-regions-array  1051  illustrated in  FIG. 3 . 
     As illustrated in  FIG. 20 , the semiconductor channel layer  2121  is stacked on the scanning line insulating film  2091  and arranged over the upper main surface  2130  of the glass substrate  2090 . The semiconductor channel layer  2121  faces the scanning line electrode  2120  across the scanning line insulating film  2091 . 
     As illustrated in  FIG. 20 , the image signal line electrode  2122  is stacked on the scanning line insulating film  2091  and the semiconductor channel layer  2121  and arranged over the upper main surface  2130  of the glass substrate  2090 . As illustrated in  FIG. 18 , the image signal line electrode  2122  contacts the image signal line  2100  and the semiconductor channel layer  2121  and is electrically connected to the image signal line  2100  and the semiconductor channel layer  2121 . 
     As illustrated in  FIG. 20 , the image signal line electrode  2123  is stacked on the scanning line insulating film  2091  and the semiconductor channel layer  2121  and arranged over the upper main surface  2130  of the glass substrate  2090 . As illustrated in  FIG. 18 , the image signal line electrode  2123  contacts the semiconductor channel layer  2121  and is electrically connected to the semiconductor channel layer  2121 . 
     As illustrated in  FIGS. 20, 21, and 22 , the interlayer insulating film  2092  is stacked on the scanning line insulating film  2091 , the image signal line  2100 , the semiconductor channel layer  2121 , the image signal line electrode  2122 , and the image signal line electrode  2123  and arranged over the upper main surface  2130  of the glass substrate  2090 . The interlayer insulating film  2092  separates the image signal line  2100 , the semiconductor channel layer  2121 , the image signal line electrode  2122 , and the image signal line electrode  2123  under the interlayer insulating film  2092  in the thickness direction of the TFT substrate  2070  from the image signal line slit electrode  2124  and the common potential line lower electrode  2125  over the interlayer insulating film  2092 , thereby insulating the image signal line  2100 , the semiconductor channel layer  2121 , the image signal line electrode  2122 , and the image signal line electrode  2123  from the image signal line slit electrode  2124  and the common potential line lower electrode  2125 . 
     As illustrated in  FIGS. 20, 21, and 22 , the common potential line lower electrode  2125  is stacked on the interlayer insulating film  2092  and arranged over the upper main surface  2130  of the glass substrate  2090 . The common potential line lower electrode  2125  includes a sheet-like electrode  2160  illustrated in  FIGS. 18, 20, 21, and 22 . As illustrated in  FIG. 18 , the sheet-like electrode  2160  has a sheet-like planar shape as viewed in the thickness direction of the TFT substrate  2070 . 
     As illustrated in  FIGS. 20, 21, and 22 , the organic planarizing film  2093  is stacked on the interlayer insulating film  2092  and the common potential line lower electrode  2125  and arranged over the upper main surface  2130  of the glass substrate  2090 . The organic planarizing film  2093  functions as an insulating film for separating the common potential line lower electrode  2125  under the organic planarizing film  2093  in the thickness direction of the TFT substrate  2070  from the image signal line slit electrode  2124  over the organic planarizing film  2093 , thereby insulating the common potential line lower electrode  2125  from the image signal line slit electrode  2124 . 
     As illustrated in  FIGS. 20, 21, and 22 , the alignment film  2094  is stacked on the organic planarizing film  2093  and arranged over the upper main surface  2130  of the glass substrate  2090 . The alignment film  2094  has an upper main surface  2140  forming the upper main surface of the TFT substrate  2070  and contacting the liquid crystal layer  2071 . The upper main surface  2140  of the alignment film  2094  is subjected to alignment process by means of a rubbing or photo-alignment method, for example. Thus, the upper main surface  2140  of the alignment film  2094  has an alignment capability of aligning liquid crystal molecules in the liquid crystal layer  2071  in a particular alignment direction. 
     As illustrated in  FIGS. 20 and 22 , the image signal line slit electrode  2124  is stacked on the organic planarizing film  2093  and arranged over the upper main surface  2130  of the glass substrate  2090 . The image signal line slit electrode  2124  is a comb-like electrode and includes a line-like electrode  2150 , a line-like electrode  2151 , a line-like electrode  2152 , and a line-like electrode  2153  illustrated in  FIGS. 18 and 22 . As illustrated in  FIG. 18 , each of the line-like electrodes  2150 ,  2151 ,  2152 , and  2153  is a line-like segment having a line-like planar shape as viewed in the thickness direction of the TFT substrate  2070  and extending in a particular extension direction indicated by the arrow AY. As illustrated in  FIGS. 18 and 22 , the line-like electrodes  2150 ,  2151 ,  2152 , and  2153  are arranged in an arrangement direction indicated by the arrow AX. 
     As illustrated in  FIGS. 18, 20, and 22 , the image signal line slit electrode  2124  and the common potential line lower electrode  2125  are arranged in such a manner as to overlap each other as viewed in the thickness direction of the TFT substrate  2070 . 
     As illustrated in  FIG. 20 , the image signal line through hole group  2126  penetrates the interlayer insulating film  2092 , the organic planarizing film  2093 , and the alignment film  2094 . The image signal line through hole group  2126  includes an image signal line through hole  2170 , an image signal line through hole  2171 , an image signal line through hole  2172 , and an image signal line through hole  2173  illustrated in  FIG. 18 . Each of the image signal line through holes  2170 ,  2171 ,  2172 , and  2173  extends in the thickness direction of the TFT substrate  2070 . As illustrated in  FIG. 18 , the image signal line through holes  2170 ,  2171 ,  2172 , and  2173  contact the image signal line electrode  2123 , respectively contact the line-like electrodes  2150 ,  2151 ,  2152 , and  2153  at their one end portions, and electrically connect the line-like electrodes  2150 ,  2151 ,  2152 , and  2153  to the image signal line electrode  2123  respectively. 
     As illustrated in  FIG. 20 , the common potential line through hole  2127  penetrates the interlayer insulating film  2092 . The common potential line through hole  2127  extends in the thickness direction of the TFT substrate  2070 . As illustrated in  FIG. 18 , the common potential line through hole  2127  contacts the common potential line  2111 , contacts the common potential line lower electrode  2125 , and electrically connects the common potential line lower electrode  2125  to the common potential line  2111 . 
     2.4 Generation of Horizontal Field 
     In the TFT, in response to application of an ON signal to the scanning line electrode  2120  to become a gate electrode illustrated in  FIGS. 18 and 20 , the image signal line electrode  2122  to become a drain illustrated in  FIGS. 18 and 20  and the image signal line electrode  2123  to become a source illustrated in  FIGS. 18 and 20  become electrically continuous with each other. In response to application of an OFF signal to the scanning line electrode  2120  to become the gate, the image signal line electrode  2122  to become the drain and the image signal line electrode  2123  to become the source become electrically discontinuous with each other. 
     When the image signal line electrode  2122  and the image signal line electrode  2123  become electrically continuous with each other, the image signal line slit electrode  2124  illustrated in  FIGS. 18, 20, and 22  is given a signal potential as a first potential applied from the image signal line  2100  illustrated in  FIGS. 18 and 21  through the image signal line electrode  2122 , the semiconductor channel layer  2121 , the image signal line electrode  2123 , and the image signal line through hole group  2126  illustrated in  FIGS. 18 and 20 . 
     The common potential line lower electrode  2125  illustrated in  FIGS. 18, 20, 21 , and  22  is given a common potential as a second potential different from the first potential and applied from the common potential line  2111  illustrated in  FIGS. 18, 20, and 21  through the common potential line through hole  2127  illustrated in  FIGS. 18 and 20 . 
     Thus, in response to application of an ON signal to the scanning line electrode  2120 , a driving voltage is applied between the image signal line slit electrode  2124  and the common potential line lower electrode  2125 . 
     When the driving voltage is applied between the image signal line slit electrode  2124  as a first pixel electrode and the common potential line lower electrode  2125  as a second pixel electrode, the common potential line lower electrode  2125  becomes involved in a field from the image signal line slit electrode  2124 , as illustrated in  FIG. 22 . More specifically, a fringe field is generated between a field concentrated part  2200  as a second field concentrated part occupying a part of an upper main surface of the sheet-like electrode  2160 , and a field concentrated part  2190  and a field concentrated part  2191  as a first field concentrated part respectively occupying substantially entire upper surfaces of the line-like electrodes  2150  and  2151  adjacent to the field concentrated part  2200 . A fringe field is generated between a field concentrated part  2201  as the second field concentrated part occupying a part of the upper main surface of the sheet-like electrode  2160 , and the field concentrated part  2191  and a field concentrated part  2192  as the first field concentrated part respectively occupying substantially entire upper surfaces of the line-like electrodes  2151  and  2152  adjacent to the field concentrated part  2201 . Further, a fringe field is generated between a field concentrated part  2202  as the second field concentrated part occupying a part of the upper main surface of the sheet-like electrode  2160 , and the field concentrated part  2192  and a field concentrated part  2193  as the first field concentrated part respectively occupying substantially entire upper surfaces of the line-like electrodes  2152  and  2153  adjacent to the field concentrated part  2202 . Each of the field concentrated parts  2200 ,  2201 , and  2202  has a line-like planar shape as viewed in the thickness direction of the TFT substrate  2070  and extends in an extension direction indicated by the arrow AY. As illustrated in  FIG. 22 , the field concentrated parts  2200 ,  2201 , and  2202  are arranged in a direction indicated by the arrow AX. As illustrated in  FIG. 22 , the field concentrated part  2200  is at an intermediate position between the line-like electrode  2150  and the line-like electrode  2151 . The field concentrated part  2201  is at an intermediate position between the line-like electrode  2151  and the line-like electrode  2152 . The field concentrated part  2202  is at an intermediate position between the line-like electrode  2152  and the line-like electrode  2153 . The generated fringe fields pass through the liquid crystal layer  2071 , as indicated by electric lines of force  2210  illustrated in  FIG. 22 . 
     2.5 Partition 
     The partition  2081  includes a line-like partition  2220 , a line-like partition  2221 , a line-like partition  2222 , and a line-like partition  2223  illustrated in  FIGS. 19 and 22 . The line-like partitions  2220 ,  2221 ,  2222 , and  2223  as a first line-like partition are arranged on the line-like electrodes  2150 ,  2151 ,  2152 , and  2153  respectively and extend in a direction substantially parallel to the direction of the alignment film  2094 . The line-like partitions  2220 ,  2221 ,  2222 , and  2223  may be formed only in partial regions on the line-like electrodes  2150 ,  2151 ,  2152 , and  2153  respectively. As illustrated in  FIG. 19 , each of the line-like partitions  2220 ,  2221 ,  2222 , and  2223  has a line-like planar shape as viewed in the thickness direction of the TFT substrate  2070  and extends in the extension direction indicated by the arrow AY, like the field concentrated parts  2190 ,  2191 ,  2192 , and  2193 . As illustrated in  FIG. 22 , the line-like partitions  2220 ,  2221 ,  2222 , and  2223  are arranged on the field concentrated parts  2190 ,  2191 ,  2192 , and  2193  respectively. As illustrated in  FIG. 22 , each of the line-like partitions  2220 ,  2221 ,  2222 , and  2223  partitions the liquid crystal layer  2071  in a partitioning direction indicated by the arrow AX. 
     The partition  2081  further includes a line-like partition  2230 , a line-like partition  2231 , and a line-like partition  2232  illustrated in  FIGS. 19 and 22 . The line-like partitions  2230 ,  2231 , and  2232  as a second line-like partition are arranged between the line-like electrodes  2150 ,  2151 ,  2152 , and  2153  and extend in a direction substantially parallel to the direction of the alignment film  2094 . As illustrated in  FIG. 19 , each of the line-like partitions  2230 ,  2231 , and  2232  has a line-like planar shape as viewed in the thickness direction of the TFT substrate  2070  and extends in the extension direction indicated by the arrow AY, like each of the field concentrated parts  2200 ,  2201 , and  2202 . As illustrated in  FIG. 22 , the line-like partitions  2230 ,  2231 , and  2232  are arranged on the field concentrated parts  2200 ,  2201 , ands  2202  respectively. As illustrated in  FIG. 22 , each of the line-like partitions  2230 ,  2231 , and  2232  partitions the liquid crystal layer  2071  in a partitioning direction indicated by the arrow AX. 
     The alignment film  2082  includes a line-like alignment film  2250 , a line-like alignment film  2251 , a line-like alignment film  2252 , a line-like alignment film  2253 , a line-like alignment film  2260 , a line-like alignment film  2261 , and a line-like alignment film  2262 . As illustrated in  FIGS. 19 and 22 , the line-like alignment films  2250 ,  2251 ,  2252 ,  2253 ,  2260 ,  2261 , and  2262  cover the line-like partitions  2220 ,  2221 ,  2222 ,  2223 ,  2230 ,  2231 , and  2232  respectively. As illustrated in  FIGS. 20, 21, and 22 , the alignment film  2082  has a surface  2270  contacting the liquid crystal layer  2071 . The surface  2270  of the alignment film  2082  is subjected to alignment process by means of a rubbing or photo-alignment method, for example. Thus, the surface  2270  of the alignment film  2082  has an alignment capability of aligning liquid crystal molecules in the liquid crystal layer  2071  in a particular direction. A direction in which liquid crystal molecules are aligned in the surface  2270  of the alignment film  2082  as a second alignment film agrees with a direction in which liquid crystal molecules are aligned in the upper main surface  2140  of the alignment film  2094  as a first alignment film. The alignment film  2082  is desirably a photo-alignment film subjected to alignment process by means of a photo-alignment method. 
     The partition  2081  desirably has a height of two-thirds or more of a liquid crystal cell gap as a gap between a part of the TFT substrate  2070  other than the partition  2081  and the alignment film  2082 , and the CF substrate  1032 . 
     2.6 Replacement with Line-Like Partition Having Forward Tapered Shape 
     If the alignment capability of the surface  2270  of the alignment film  2082  illustrated in  FIGS. 20, 21, and 22  is achieved by employing a photo-alignment system, the line-like partitions  2220 ,  2221 ,  2222 ,  2223 ,  2230 ,  2231 , and  2232  each having a side surface pointed in the extension direction of the TFT substrate  2070  may be replaced, according to an alignment condition, with line-like partitions each having a side surface pointed in a direction tilted from the extension direction of the TFT substrate  2070 . Namely, each of the line-like partitions  2220 ,  2221 ,  2222 ,  2223 ,  2230 ,  2231 , and  2232  may be replaced with a line-like partition having a forward tapered shape with a width that gets smaller with a greater distance from the TFT substrate  2070 . This replacement causes light to easily impinge on a part of the alignment film  2082  covering a side surface of the line-like partition, making it possible to give an alignment capability to the surface  2270  of the alignment film  2082  easily by means of alignment process using an ultraviolet ray. 
     2.7 Replacement with Line-Like Electrode or Line-Like Partition Further Functioning as Light Shield 
     To suppress leakage of light due to instability of the direction of the liquid crystal director occurring near the line-like partitions  2220 ,  2221 ,  2222 , and  2223  illustrated in  FIGS. 19 and 22 , the line-like electrodes  2150 ,  2151 ,  2152 , and  2153  having the same widths as the line-like partitions  2220 ,  2221 ,  2222 , and  2223  respectively may be replaced with line-like electrodes made of a non-transparent material and having greater widths than the line-like partitions  2220 ,  2221 ,  2222 , and  2223 . This replacement makes the line-like electrode further function as a light shield to suppress leakage of light. Alternatively, each of the line-like partitions  2220 ,  2221 ,  2222 ,  2223 ,  2230 ,  2231 , and  2232  may be replaced with a line-like partition having a forward tapered shape made of a non-transparent material. This replacement makes the line-like partition further function as a light shield to suppress leakage of light. 
     2.8 Analysis of Response Speed During Falling Time by Simulation 
     In the following description, response speed during the falling time in the absence of a partition such as the partition  2081  and response speed during the falling time in the presence of a partition such as the partition  2081  are analyzed by simulation to show that response time during the falling time in the presence of a partition such as the partition  2081  is about one-third of response time during the falling time in the absence of a partition such as the partition  2081 . 
     A used simulator is LCDMaster 2D (Ver. 8.5.2) available from SHINTECH, Inc. Table 1 given above shows the physical property values of the liquid crystal material MS-5355XX-K forming a liquid crystal layer in a structure model used in the simulation. Table 2 given above shows common parameters common to structure models used in the simulation. The structure models used in the simulation were simplified to a maximum within a range in which the appropriateness of the structure models can be guaranteed. 
     2.9 Analysis of Response Speed During Falling Time by Simulation in the Absence of Partition 
       FIG. 23  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the absence of a partition. 
     A structure model  2500  illustrated in  FIG. 23  is produced by modeling a minimum recurring unit of a liquid crystal cell of the fringe field switching (FFS) system, and includes a lower substrate  2510 , an upper counter substrate  2511 , and a liquid crystal layer  2512 . The lower substrate  2510  includes a lower glass substrate  2520 , an organic planarizing film  2521 , an image signal line slit electrode  2522 , and a common potential line lower electrode  2523 . The image signal line slit electrode  2522  includes a line-like electrode  2530 , a line-like electrode  2531 , and a line-like electrode  2532 . The common potential line lower electrode  2523  includes a sheet-like electrode  2540 . 
     The liquid crystal material MS-5355XX-K is poured in between an upper main surface  2550  of the lower substrate  2510  and a lower main surface  2551  of the upper counter substrate  2511  to form the liquid crystal layer  2512  made of the liquid crystal material MS-5355XX-K. An alignment film not illustrated covering the upper main surface  2550  of the lower substrate  2510  is subjected to alignment process for aligning liquid crystal molecules in the liquid crystal layer  2512  in a first direction. An alignment film not illustrated covering the lower main surface  2551  of the upper counter substrate  2511  is subjected to alignment process for aligning the liquid crystal molecules in the liquid crystal layer  2512  in a second direction perpendicular to the first direction. Each of the line-like electrodes  2530 ,  2531 , and  2532  has a width of 3.0 μm. A gap between two adjacent ones of the line-like electrodes  2530 ,  2531 , and  2532  is 9.0 μm. A liquid crystal cell gap, which is a distance from the upper main surface  2550  of the lower substrate  2510  to the lower main surface  2551  of the upper counter substrate  2511 , is 3.0 μm. 
     2.10 Analysis of Response Speed During Falling Time by Simulation in the Presence of Partition 
       FIG. 24  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the presence of a partition. 
     A structure model  2600  illustrated in  FIG. 24  is produced by modeling a minimum recurring unit of a liquid crystal cell of the FFS system to which partition is added, and includes a lower substrate  2610 , an upper counter substrate  2611 , and a liquid crystal layer  2612 . The lower substrate  2610  includes a lower glass substrate  2620 , an organic planarizing film  2621 , an image signal line slit electrode  2622 , a common potential line lower electrode  2623 , and a partition  2624 . The image signal line slit electrode  2622  includes a line-like electrode  2630 , a line-like electrode  2631 , and a line-like electrode  2632 . The common potential line lower electrode  2623  includes a sheet-like electrode  2640 . The partition  2624  includes a line-like partition  2650 , a line-like partition  2651 , a line-like partition  2652 , a line-like partition  2660 , and a line-like partition  2661 . 
     The liquid crystal material MS-5355XX-K is poured in between an upper main surface  2670  of the lower substrate  2610  and a lower main surface  2671  of the upper counter substrate  2611  to form the liquid crystal layer  2612  made of the liquid crystal material MS-5355XX-K. An alignment film not illustrated covering the upper main surface  2670  of the lower substrate  2610  is subjected to alignment process for aligning liquid crystal molecules in the liquid crystal layer  2612  in a first direction. An alignment film not illustrated covering the lower main surface  2671  of the upper counter substrate  2611  is subjected to alignment process for aligning the liquid crystal molecules in the liquid crystal layer  2612  in a second direction perpendicular to the first direction. Each of the line-like electrodes  2630 ,  2631 , and  2632  has a width of 3.0 μm. A gap between two adjacent ones of the line-like electrodes  2630 ,  2631 , and  2632  is 9.0 μm. A liquid crystal cell gap is 3.0 μm. 
     The line-like partitions  2650 ,  2651 , and  2652  are arranged on the line-like electrodes  2630 ,  2631 , and  2632  respectively. 
     The line-like partition  2660  is arranged on a field concentrated part  2680  at an intermediate position between the position of the line-like electrode  2630  and the position of the line-like electrode  2631 . The line-like partition  2661  is arranged on a field concentrated part  2681  at an intermediate position between the position of the line-like electrode  2631  and the position of the line-like electrode  2632 . 
     Each of the line-like partitions  2650 ,  2651 ,  2652 ,  2660 , and  2661  has a height of 2.0 μm lower than the liquid crystal cell gap. This forms a gap of a height of 1.0 μm between each of the line-like partitions  2650 ,  2651 ,  2652 ,  2660 , and  2661  and the upper counter substrate  2611 . 
     2.11 Comparison Between the Absence of Partition and the Presence of Partition 
       FIG. 25  is a graph showing response curves obtained by evaluating response characteristics using the structure model in the absence of a partition illustrated in  FIG. 23  and the structure model in the presence of a partition illustrated in  FIG. 24 . 
     The response characteristics were evaluated in the same manner as in the first embodiment. 
     As shown in  FIG. 25 , rising and falling of a response curve corresponding to use of the structure model  2600  in the presence of the partition  2624  illustrated in  FIG. 24  are respectively steeper than rising and falling of a response curve corresponding to use of the structure model  2500  in the absence of a partition illustrated in  FIG. 23 . 
     Table 4 shows a rising period and a falling period determined by the use of the structure model  2500  illustrated in  FIG. 23  in the absence of a partition and corresponding periods determined by the use of the structure model  2600  illustrated in  FIG. 24  in the presence of the partition  2624 . 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 Second embodiment 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Electrode 
                 Gap between 
                 Cell 
                 Rising 
                 Falling 
                 Brightness 
               
               
                 System 
                 width 
                 electrodes 
                 gap 
                 period 
                 period 
                 transmittance 
               
               
                   
               
               
                 Without partition 
                 3.0 μm 
                 9.0 μm 
                 3.0 μm 
                 16.4 ms 
                 12.4 ms 
                 66.4% 
               
               
                 With partition 
                 3.0 μm 
                 9.0 μm 
                 3.0 μm 
                  5.0 ms 
                  5.2 ms 
                 32.7% 
               
               
                   
               
            
           
         
       
     
     As understood from Table 4, the falling period determined by the use of the structure model  2600  illustrated in  FIG. 24  in the presence of the partition  2624  is about one-third of the falling period determined by the use of the structure model  2500  illustrated in  FIG. 23  in the absence of a partition. 
     3. Third Embodiment 
     3.1 Main Difference Between First Embodiment and Third Embodiment 
     A third embodiment relates to a liquid crystal display of the horizontal field system. 
     The first embodiment and the third embodiment differ from each other mainly in the following. In the first embodiment, the partition  1081  is arranged on the image signal line slit electrode  1124  and the common potential line slit electrode  1125 . In the third embodiment, while a partition is arranged on the image signal line slit electrode  1124 , a partition is not arranged on the common potential line slit electrode  1125 . Structures or modifications thereof employed in liquid crystal displays of the other embodiments may also be employed in the liquid crystal display of the third embodiment within a range in which structures resulting in the foregoing main difference can be employed without any interference. 
     3.2 Liquid Crystal Display, Liquid Crystal Panel, and Display Region 
     The schematic view of  FIG. 1  is also a perspective view illustrating the liquid crystal display of the third embodiment. The schematic view of  FIG. 2  is also a sectional view illustrating a section of a liquid crystal panel provided in the liquid crystal display of the third embodiment. The schematic view of  FIG. 3  is also a plan view illustrating a TFT substrate, a printed board, and an integrated circuit chip provided in the liquid crystal display of the third embodiment. 
     3.3 Configuration of TFT Substrate 
     The schematic view of  FIG. 4  is also a plan view illustrating planar arrangement of a line, an electrode, and a semiconductor channel layer provided in the liquid crystal display of the third embodiment. The schematic view of  FIG. 26  is a plan view illustrating planar arrangement of an organic planarizing film, an electrode, a partition, and an alignment film provided in the liquid crystal display of the third embodiment.  FIGS. 27, 28, and 29  are sectional views each illustrating sections of the TFT substrate and a liquid crystal layer provided in the liquid crystal display of the third embodiment. 
       FIG. 27  illustrates a section taken at a position along a cutting line A-A′ in  FIGS. 4 and 26 .  FIG. 28  illustrates a section taken at a position along a cutting line B-B′ in  FIGS. 4 and 26 .  FIG. 29  illustrates a section taken at a position along a cutting line C-C′ in  FIGS. 4 and 26 . 
       FIGS. 4, 26, 27, 28, and 29  illustrate the each pixel region  1060  illustrated in  FIG. 3 . 
     A TFT substrate  3070  illustrated in  FIGS. 4, 26, 27, 28, and 29  becomes the TFT substrate  1030  illustrated in  FIGS. 1, 2, and 3 . A liquid crystal layer  3071  illustrated in  FIGS. 27, 28, and 29  becomes the liquid crystal layer  1031  illustrated in  FIG. 2 . 
       FIG. 4  illustrates the image signal line  1100 , the scanning line  1110 , the common potential line  1111 , the scanning line electrode  1120 , the semiconductor channel layer  1121 , the image signal line electrode  1122 , the image signal line electrode  1123 , the image signal line slit electrode  1124 , the common potential line slit electrode  1125 , the image signal line through hole group  1126 , and the common potential line through hole group  1127  provided in the TFT substrate  3070 , which are structures corresponding to those of the first embodiment. 
       FIG. 26  illustrates the organic planarizing film  1093  and the common potential line slit electrode  1125  provided in the TFT substrate  3070 , which are structures corresponding to those of the first embodiment.  FIG. 26  further illustrates a partition  3081  and an alignment film  3082  provided in the TFT substrate  3070 . 
       FIG. 27  illustrates the glass substrate  1090 , the scanning line insulating film  1091 , the interlayer insulating film  1092 , the organic planarizing film  1093 , the common potential line  1111 , the scanning line electrode  1120 , the semiconductor channel layer  1121 , the image signal line electrode  1122 , the image signal line electrode  1123 , the image signal line slit electrode  1124 , and the image signal line through hole group  1126  provided in the TFT substrate  3070 , which are structures corresponding to those of the first embodiment.  FIG. 27  further illustrates an alignment film  3094 , a partition  3081 , and an alignment film  3082  provided in the TFT substrate  3070 . 
       FIG. 28  illustrates the glass substrate  1090 , the scanning line insulating film  1091 , the interlayer insulating film  1092 , the organic planarizing film  1093 , the image signal line  1100 , the scanning line  1110 , the common potential line  1111 , the common potential line slit electrode  1125 , and the common potential line through hole group  1127  provided in the TFT substrate  3070 , which are structures corresponding to those of the first embodiment.  FIG. 28  further illustrates the alignment film  3094  provided in the TFT substrate  3070 . 
       FIG. 29  illustrates the glass substrate  1090 , the scanning line insulating film  1091 , the interlayer insulating film  1092 , the organic planarizing film  1093 , the image signal line slit electrode  1124 , and the common potential line slit electrode  1125  provided in the TFT substrate  3070 , which are structures corresponding to those of the first embodiment.  FIG. 29  further illustrates the alignment film  3094 , the partition  3081 , and the alignment film  3082  provided in the TFT substrate  3070 . 
     The scanning line insulating film  1091 , the scanning line electrode  1120 , the semiconductor channel layer  1121 , the image signal line electrode  1122 , and the image signal line electrode  1123  form a TFT. The image signal line slit electrode  1124  and the common potential line slit electrode  1125  form a pixel electrode. 
     The image signal line slit electrode  1124  includes the line-like electrodes  1150 ,  1151 , and  1152  illustrated in  FIGS. 4 and 29 , which are structures corresponding to those of the first embodiment. The common potential line slit electrode  1125  includes the line-like electrodes  1160  and  1161  illustrated in  FIGS. 4 and 29 , which are structures corresponding to those of the first embodiment. 
     As illustrated in  FIGS. 27, 28, and 29 , the alignment film  3094  is stacked on the organic planarizing film  1093  and the common potential line slit electrode  1125  and arranged over the upper main surface  1130  of the glass substrate  1090 . The alignment film  3094  has an upper main surface  3140  forming the upper main surface of the TFT substrate  3070  and contacting the liquid crystal layer  3071 . The upper main surface  3140  of the alignment film  3094  is subjected to alignment process by means of a rubbing or photo-alignment method, for example. Thus, the upper main surface  3140  of the alignment film  3094  has an alignment capability of aligning liquid crystal molecules in the liquid crystal layer  3071  in a particular alignment direction. 
     The partition  3081  desirably has a height of two-thirds or more of a liquid crystal cell gap as a gap between a part of the TFT substrate  3070  other than the partition  3081  and the alignment film  3082 , and the CF substrate  1032 . 
     3.4 Generation of Horizontal Field 
     Like in the first embodiment, in response to application of an ON signal to the scanning line electrode  1120  illustrated in  FIGS. 4 and 27 , a driving voltage is applied between the image signal line slit electrode  1124  illustrated in  FIGS. 4, 27, and 29  and the common potential line slit electrode  1125  illustrated in  FIGS. 4, 26, 28, and 29 . 
     When the driving voltage is applied between the image signal line slit electrode  1124  as a first pixel electrode and the common potential line slit electrode  1125  as a second pixel electrode, a horizontal field is generated between the field concentrated part  1200  as a second field concentrated part occupying a substantially entire upper surface of the line-like electrode  1160 , and the field concentrated parts  1190  and  1191  as a first field concentrated part respectively occupying substantially entire upper surfaces of the line-like electrodes  1150  and  1151  adjacent to the line-like electrode  1160 , as illustrated in  FIG. 29 . Further, a horizontal field is generated between the field concentrated part  1201  as the second field concentrated part occupying a substantially entire upper surface of the line-like electrode  1161 , and the field concentrated parts  1191  and  1192  as the first field concentrated part respectively occupying substantially entire upper surfaces of the line-like electrodes  1151  and  1152  adjacent to the line-like electrode  1161 . The generated horizontal fields pass through the liquid crystal layer  3071 , as indicated by the electric lines of force  1210  illustrated in  FIG. 29 . 
     3.5 Partition 
     The partition  3081  includes a line-like partition  3220 , a line-like partition  3221 , and a line-like partition  3222  illustrated in  FIGS. 26 and 29 . The line-like partitions  3220 ,  3221 , and  3222  are arranged on the line-like electrodes  1150 ,  1151 , and  1152  respectively and are substantially parallel to the direction of the alignment film  3094 . The line-like partitions  3220 ,  3221 , and  3222  may be formed only in partial regions on the line-like electrodes  1150 ,  1151 , and  1152  respectively. As illustrated in  FIG. 26 , each of the line-like partitions  3220 ,  3221 , and  3222  has a line-like planar shape as viewed in the thickness direction of the TFT substrate  3070  and extends in the extension direction indicated by the arrow AY, like each of the field concentrated parts  1190 ,  1191 , and  1192 . As illustrated in  FIG. 29 , the line-like partitions  3220 ,  3221 , and  3222  are arranged on the field concentrated parts  1190 ,  1191 , and  1192  respectively. As illustrated in  FIG. 29 , each of the line-like partitions  3220 ,  3221 , and  3222  partitions the liquid crystal layer  3071  in a partitioning direction indicated by the arrow AX. 
     Meanwhile, as illustrated in  FIG. 29 , a line-like partition is not arranged on the field concentrated parts  1200  and  1201 . 
     The alignment film  3082  includes a line-like alignment film  3250 , a line-like alignment film  3251 , and a line-like alignment film  3251  illustrated in  FIGS. 26 and 29 . As illustrated in  FIGS. 26 and 29 , the line-like alignment films  3250 ,  3251 , and  3251  cover the line-like partitions  3220 ,  3221 , and  3222  respectively. As illustrated in  FIGS. 27 and 29 , the alignment film  3082  has a surface  3270  contacting the liquid crystal layer  3071 . The surface  3270  of the alignment film  3082  is subjected to alignment process by means of a rubbing or photo-alignment method, for example. Thus, the surface  3270  of the alignment film  3082  has an alignment capability of aligning liquid crystal molecules in the liquid crystal layer  3071  in a particular direction. A direction in which liquid crystal molecules are aligned in the surface  3270  of the alignment film  3082  as a second alignment film agrees with a direction in which liquid crystal molecules are aligned in the upper main surface  3140  of the alignment film  3094  as a first alignment film. The alignment film  3082  is desirably a photo-alignment film subjected to alignment process by means of a photo-alignment method. 
     Like in the first embodiment, a line-like partition having a forward tapered shape may be used as an alternative, Further, a line-like electrode or a line-like partition further functioning as a light shield may be used as an alternative. 
     3.6 Analysis of Response Speed During Falling Time by Simulation 
     In the following description, response speed during the falling time in the presence of a partition such as the partition  3081  is analyzed by simulation to show that response time during the falling time in the presence of a partition such as the partition  3081  is about half of response time during the falling time in the absence of a partition such as the partition  3081 . 
     A used simulator is LCDMaster 2D (Ver. 8.5.2) available from SHINTECH, Inc. Table 1 given above shows the physical property values of the liquid crystal material MS-5355XX-K forming a liquid crystal layer in a structure model used in the simulation. Table 2 given above shows common parameters common to structure models used in the simulation. The structure models used in the simulation were simplified to a maximum within a range in which the appropriateness of the structure models can be guaranteed. 
       FIG. 30  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the presence of a partition. 
     A structure model  3600  illustrated in  FIG. 30  is produced by modeling a minimum recurring unit of a liquid crystal cell of the IPS system to which partition is added, and includes a lower substrate  3610 , an upper counter substrate  3611 , and a liquid crystal layer  3612 . The lower substrate  3610  includes a lower glass substrate  3620 , an organic planarizing film  3621 , an image signal line slit electrode  3622 , a common potential line slit electrode  3623 , and a partition  3624 . The image signal line slit electrode  3622  includes a line-like electrode  3630 . The common potential line slit electrode  3623  includes a line-like electrode  3640  and a line-like electrode  3641 . The partition  3624  includes a line-like partition  3650 . 
     The liquid crystal material MS-5355XX-K is poured in between an upper main surface  3670  of the lower substrate  3610  and a lower main surface  3671  of the upper counter substrate  3611  to form the liquid crystal layer  3612  made of the liquid crystal material MS-5355XX-K. An alignment film not illustrated covering the upper main surface  3670  of the lower substrate  3610  is subjected to alignment process for aligning liquid crystal molecules in the liquid crystal layer  3612  in a first direction. An alignment film not illustrated covering the lower main surface  3671  of the upper counter substrate  3611  is subjected to alignment process for aligning the liquid crystal molecules in the liquid crystal layer  3612  in a second direction perpendicular to the first direction. Each of the line-like electrodes  3630 ,  3640 , and  3641  has a width of 1.5 μM. A gap between two adjacent ones of the line-like electrodes  3630 ,  3640 , and  3641  is 1.5 μm. A liquid crystal cell gap is 3.0 μm. 
     The line-like partition  3650  is arranged on the line-like electrodes  3630 . 
     The line-like partition  3650  has a width of 1.5 μm like the line-like electrode  3630 , and has a height of 2.0 μm lower than the liquid crystal cell gap. This forms a gap of a height of 1.0 μm between the line-like partition  3650  and the upper counter substrate  3611 . 
       FIG. 31  is a graph showing response curves obtained by evaluating response characteristics using the structure model in the absence of a partition illustrated in  FIG. 13  and the structure model in the presence of a partition illustrated in  FIG. 30 . 
     The response characteristics were evaluated in the same manner as in the first embodiment. 
     As illustrated in  FIG. 31 , rising and falling of a response curve corresponding to use of the structure model  3600  in the presence of the partition  3624  illustrated in  FIG. 30  are respectively steeper than rising and falling of a response curve corresponding to use of the structure model  1500  in the absence of a partition illustrated in  FIG. 13 . 
     Table 5 shows a rising period and a falling period determined by the use of the structure model  1500  illustrated in  FIG. 13  in the absence of a partition and corresponding periods determined by the use of the structure model  3600  illustrated in  FIG. 30  in the presence of the partition  3624 . 
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 Third embodiment 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Electrode 
                 Gap between 
                 Cell 
                 Rising 
                 Falling 
                 Brightness 
               
               
                 System 
                 width 
                 electrodes 
                 gap 
                 period 
                 period 
                 transmittance 
               
               
                   
               
               
                 Without partition 
                 1.5 μm 
                 1.5 μm 
                 3.0 μm 
                 12.2 ms 
                 12.4 ms 
                 77.0% 
               
               
                 With partition 
                 1.5 μm 
                 1.5 μm 
                 3.0 μm 
                  8.8 ms 
                  6.0 ms 
                 45.7% 
               
               
                   
               
            
           
         
       
     
     As understood from Table 5, the falling period determined by the use of the structure model  3600  illustrated in  FIG. 30  in the presence of the partition  3624  is about half of the falling period determined by the use of the structure model  1500  illustrated in  FIG. 13  in the absence of a partition. 
     3.7 Others 
     The image signal line slit electrode  1124  is equivalent in terms of potential difference to the common potential line slit electrode  1125 . Thus, the effect of shortening a falling period can also be achieved by omitting a partition from above the image signal line slit electrode  1124  and arranging a partition on the common potential line slit electrode  1125  instead of arranging a partition on the image signal line slit electrode  1124  and omitting a partition from above the common potential line slit electrode  1125  as illustrated in  FIG. 29 . 
     4. Fourth Embodiment 
     4.1 Main Difference Between Second Embodiment and Fourth Embodiment 
     A fourth embodiment relates to a liquid crystal display of the horizontal field system. 
     The second embodiment and the fourth embodiment differ from each other mainly in the following. In the second embodiment, the partition  2081  is arranged on the field concentrated parts  2190 ,  2191 ,  2192 , and  2193  at the image signal line slit electrode  2124  and on the field concentrated parts  2200 ,  2201 , and  2202  at the common potential line lower electrode  2125 , as illustrated in  FIG. 22 . In the fourth embodiment, while a partition is arranged on the field concentrated parts  2190 ,  2191 ,  2192 , and  2193  at the image signal line slit electrode  2124 , a partition is not arranged on the field concentrated parts  2200 ,  2201 , and  2202  at the common potential line lower electrode  2125 . Structures or modifications thereof employed in liquid crystal displays of the other embodiments may also be employed in the liquid crystal display of the fourth embodiment within a range in which structures resulting in the foregoing main difference can be employed without any interference. 
     4.2 Liquid Crystal Display, Liquid Crystal Panel, and Display Region of TFT Substrate 
     The schematic view of  FIG. 1  is also a perspective view illustrating the liquid crystal display of the fourth embodiment. The schematic view of  FIG. 2  is also a sectional view illustrating a section of a liquid crystal panel provided in the liquid crystal display of the fourth embodiment. The schematic view of  FIG. 3  is also a plan view illustrating a TFT substrate, a printed board, and an integrated circuit chip provided in the liquid crystal display of the fourth embodiment. 
     4.3 Configuration of TFT Substrate 
     The schematic view of  FIG. 18  is a plan view illustrating planar arrangement of a line, an electrode, and a semiconductor channel layer provided in the liquid crystal display of the fourth embodiment. The schematic view of  FIG. 32  is a plan view illustrating planar arrangement of an organic planarizing film, a partition, and an alignment film provided in the liquid crystal display of the fourth embodiment.  FIGS. 33, 34, and 35  are sectional views each illustrating sections of the TFT substrate and a liquid crystal layer provided in the liquid crystal display of the fourth embodiment. 
       FIG. 33  illustrates a section taken at a position along a cutting line A-A′ in FIGS.  18  and  32 .  FIG. 34  illustrates a section taken at a position along a cutting line B-B′ in  FIGS. 18 and 32 .  FIG. 35  illustrates a section taken at a position along a cutting line C-C′ in  FIGS. 18 and 32 . 
     A TFT substrate  4070  illustrated in  FIGS. 18, 32, 33, 34, and 35  becomes the TFT substrate  1030  illustrated in  FIGS. 1, 2, and 3 . A liquid crystal layer  4071  illustrated in  FIGS. 33, 34, and 35  becomes the liquid crystal layer  1031  illustrated in  FIG. 2 . 
       FIG. 18  illustrates the image signal line  2100 , the scanning line  2110 , the common potential line  2111 , the scanning line electrode  2120 , the semiconductor channel layer  2121 , the image signal line electrode  2122 , the image signal line electrode  2123 , the image signal line slit electrode  2124 , the common potential line lower electrode  2125 , the image signal line through hole group  2126 , and the common potential line through hole  2127  provided in the TFT substrate  4070 , which are structures corresponding to those of the second embodiments. 
       FIG. 32  illustrates the organic planarizing film  2093  provided in the TFT substrate  4070 , which is a structure corresponding to that of the second embodiment.  FIG. 32  further illustrates a partition  4081  and an alignment film  4082  provided in the TFT substrate  4070 . 
       FIG. 33  illustrates the glass substrate  2090 , the scanning line insulating film  2091 , the interlayer insulating film  2092 , the organic planarizing film  2093 , the common potential line  2111 , the scanning line electrode  2120 , the semiconductor channel layer  2121 , the image signal line electrode  2122 , the image signal line electrode  2123 , the image signal line slit electrode  2124 , the common potential line lower electrode  2125 , the image signal line through hole group  2126 , and the common potential line through hole  2127  provided in the TFT substrate  4070 , which are structures corresponding to those of the second embodiment.  FIG. 33  further illustrates an alignment film  4094 , the partition  4081 , and the alignment film  4082  provided in the TFT substrate  4070 . 
       FIG. 34  illustrates the glass substrate  2090 , the scanning line insulating film  2091 , the interlayer insulating film  2092 , the organic planarizing film  2093 , the image signal line  2100 , the scanning line  2110 , the common potential line  2111 , and the common potential line lower electrode  2125  provided in the TFT substrate  4070 , which are structures corresponding to those of the second embodiment.  FIG. 34  further illustrates the alignment film  4094  provided in the TFT substrate  4070 . 
       FIG. 35  illustrates the glass substrate  2090 , the scanning line insulating film  2091 , the interlayer insulating film  2092 , the organic planarizing film  2093 , the image signal line slit electrode  2124 , and the common potential line lower electrode  2125  provided in the TFT substrate  4070 , which are structures corresponding to those of the second embodiment.  FIG. 35  further illustrates the alignment film  4094 , the partition  4081 , and the alignment film  4082  provided in the TFT substrate  4070 . 
     The scanning line insulating film  2091 , the scanning line electrode  2120 , the semiconductor channel layer  2121 , the image signal line electrode  2122 , and the image signal line electrode  2123  form a TFT. The image signal line slit electrode  2124  and the common potential line lower electrode  2125  form a pixel electrode. 
     The common potential line lower electrode  2125  includes the sheet-like electrode  2160  illustrated in  FIGS. 18, 33, 34, and 35 , which is a structure corresponding to that of the second embodiment. The image signal line slit electrode  2124  includes the line-like electrodes  2150 ,  2151 ,  2152 , and  2153  illustrated in  FIGS. 18 and 35 , which are structures corresponding to those of the second embodiment. 
     As illustrated in  FIGS. 33, 34, and 35 , the alignment film  4094  is stacked on the organic planarizing film  2093  and arranged over the upper main surface  2130  of the glass substrate  2090 . The alignment film  4094  has an upper main surface  4140  forming the upper main surface of the TFT substrate  4070  and contacting the liquid crystal layer  4071 . The upper main surface  4140  of the alignment film  4094  is subjected to alignment process by means of a rubbing or photo-alignment method, for example. Thus, the upper main surface  4140  of the alignment film  4094  has an alignment capability of aligning liquid crystal molecules in the liquid crystal layer  4071  in a particular alignment direction. 
     The partition  4081  desirably has a height of two-thirds or more of a liquid crystal cell gap as a gap between a part of the TFT substrate  4070  other than the partition  4081  and the alignment film  4082 , and the CF substrate  1032 . 
     4.4 Generation of Horizontal Field 
     Like in the second embodiment, in response to application of an ON signal to the scanning line electrode  2120  illustrated in  FIGS. 18 and 33 , a driving voltage is applied between the image signal line slit electrode  2124  illustrated in  FIGS. 18, 33, and 35  and the common potential line lower electrode  2125  illustrated in  FIGS. 18, 34, and 35 . 
     When the driving voltage is applied between the image signal line slit electrode  2124  as a first pixel electrode and the common potential line lower electrode  2125  as a second pixel electrode, the common potential line lower electrode  2125  becomes involved in a field from the image signal line slit electrode  2124 . More specifically, as illustrated in  FIG. 35 , a fringe field is generated between the field concentrated part  2200  as a second field concentrated part occupying a part of the upper main surface of the sheet-like electrode  2160 , and the field concentrated parts  2190  and  2191  as a first field concentrated part respectively occupying substantially entire upper surfaces of the line-like electrodes  2150  and  2151  adjacent to the field concentrated part  2200 . A fringe field is generated between the field concentrated part  2201  as the second field concentrated part occupying a part of the upper main surface of the sheet-like electrode  2160 , and the field concentrated parts  2191  and  2192  as the first field concentrated part respectively occupying substantially entire upper surfaces of the line-like electrodes  2151  and  2152  adjacent to the field concentrated part  2201 . Further, a fringe field is generated between the field concentrated part  2202  as the second field concentrated part occupying a part of the upper main surface of the sheet-like electrode  2160 , and the field concentrated parts  2192  and  2193  as the first field concentrated part respectively occupying substantially entire upper surfaces of the line-like electrodes  2152  and  2153  adjacent to the field concentrated part  2202 . Each of the field concentrated parts  2200 ,  2201 , and  2202  has a line-like planar shape as viewed in the thickness direction of the TFT substrate  4070  and extends in an extension direction indicated by the arrow AY. As illustrated in  FIG. 35 , the field concentrated parts  2200 ,  2201 , and  2202  are arranged in a direction indicated by the arrow AX. As illustrated in  FIG. 35 , the field concentrated part  2200  is at an intermediate position between the line-like electrode  2150  and the line-like electrode  2151 . The field concentrated part  2201  is at an intermediate position between the line-like electrode  2151  and the line-like electrode  2152 . The field concentrated part  2202  is at an intermediate position between the line-like electrode  2152  and the line-like electrode  2153 . The generated fringe fields pass through the liquid crystal layer  4071 , as indicated by the electric lines of force  2210  illustrated in  FIG. 35 . 
     4.5 Partition 
     The partition  4081  includes a line-like partition  4220 , a line-like partition  4221 , a line-like partition  4222 , and a line-like partition  4223  illustrated in  FIGS. 32 and 35 . The line-like partitions  4220 ,  4221 ,  4222 , and  4223  are arranged on the line-like electrodes  2150 ,  2151 ,  2152 , and  2153  respectively and extend in a direction substantially parallel to the direction of the alignment film  4094 . The line-like partitions  4220 ,  4221 ,  4222 , and  4223  may be formed only in partial regions on the line-like electrodes  2150 ,  2151 ,  2152 , and  2153  respectively. As illustrated in  FIG. 32 , each of the line-like partitions  4220 ,  4201 ,  4202 , and  4203  has a line-like planar shape as viewed in the thickness direction of the TFT substrate  4070  and extends in the extension direction indicated by the arrow AY, like each the field concentrated parts  2190 ,  2191 ,  2192 , and  2193 . As illustrated in  FIG. 35 , the line-like partitions  4220 ,  4221 ,  4222 , and  4223  are arranged on the field concentrated parts  2190 ,  2191 ,  2192 , and  2193  respectively. As illustrated in  FIG. 35 , each of the line-like partitions  4220 ,  4221 ,  4222 , and  4223  partitions the liquid crystal layer  4071  in a partitioning direction indicated by the arrow AX. 
     Meanwhile, as illustrated in  FIG. 35 , a line-like partition is not arranged on the field concentrated parts  2200 ,  2201 , and  2202 . 
     The alignment film  4082  includes a line-like alignment film  4250 , a line-like alignment film  4251 , a line-like alignment film  4252 , and a line-like alignment film  4253  illustrated in  FIGS. 32 and 35 . As illustrated in  FIGS. 32 and 35 , the line-like alignment films  4250 ,  4251 ,  4252 , and  4253  cover the line-like partitions  4220 ,  4221 ,  4222 , and  4223  respectively. As illustrated in  FIGS. 33 and 35 , the alignment film  4082  has a surface  4270  contacting the liquid crystal layer  4071 . The surface  4270  of the alignment film  4082  is subjected to alignment process by means of a rubbing or photo-alignment method, for example. Thus, the surface  4270  of the alignment film  4082  has an alignment capability of aligning liquid crystal molecules in the liquid crystal layer  4071  in a particular alignment direction. A direction in which liquid crystal molecules are aligned in the surface  4270  of the alignment film  4082  as a second alignment film agrees with a direction in which liquid crystal molecules are aligned in the upper main surface  4140  of the alignment film  4094  as a first alignment film. The alignment film  4082  is desirably a photo-alignment film subjected to alignment process by means of a photo-alignment method. 
     Like in the second embodiment, a line-like partition having a forward tapered shape may be used as an alternative, Further, a line-like electrode or a line-like partition further functioning as a light shield may be used as an alternative. 
     4.6 Analysis of Response Speed During Falling Time by Simulation 
     In the following description, response speed during the falling time in the presence of a partition such as the partition  4081  is analyzed by simulation to show that response time during the falling time in the presence of a partition such as the partition  4081  is shorter than response time during the falling time in the absence of a partition such as the partition  4081 . 
     A used simulator is LCDMaster 2D (Ver. 8.5.2) available from SHINTECH, Inc. Table 1 given above shows the physical property values of the liquid crystal material MS-5355XX-K forming a liquid crystal layer in a structure model used in the simulation. Table 2 given above shows common parameters common to structure models used in the simulation. The structure models used in the simulation were simplified to a maximum within a range in which the appropriateness of the structure models can be guaranteed. 
       FIG. 36  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the presence of a partition. 
     A structure model  4600  illustrated in  FIG. 36  is produced by modeling a minimum recurring unit of a liquid crystal cell of the FFS system to which partition is added, and includes a lower substrate  4610 , an upper counter substrate  4611 , and a liquid crystal layer  4612 . The lower substrate  4610  includes a lower glass substrate  4620 , an organic planarizing film  4621 , an image signal line slit electrode  4622 , a common potential line lower electrode  4623 , and a partition  4624 . The image signal line slit electrode  4622  includes a line-like electrode  4630 , a line-like electrode  4631 , and a line-like electrode  4632 . The common potential line lower electrode  4623  includes a sheet-like electrode  4640 . 
     The liquid crystal material MS-5355XX-K is poured in between an upper main surface  4670  of the lower substrate  4610  and a lower main surface  4671  of the upper counter substrate  4611  to form the liquid crystal layer  4612  made of the liquid crystal material MS-5355XX-K. An alignment film not illustrated covering the upper main surface  4670  of the lower substrate  4610  is subjected to alignment process for aligning liquid crystal molecules in the liquid crystal layer  4612  in a first direction. An alignment film not illustrated covering the lower main surface  4671  of the upper counter substrate  4611  is subjected to alignment process for aligning the liquid crystal molecules in the liquid crystal layer  4612  in a second direction perpendicular to the first direction. Each of the line-like electrodes  4630 ,  4631 , and  4632  has a width of 3.0 μm. A gap between two adjacent ones of the line-like electrodes  4630 ,  4631 , and  4632  is 9.0 μm. A liquid crystal cell gap is 3.0 μm. 
     A line-like partition  4650 , a line-like partition  4651 , and a line-like partition  4652  are arranged on the line-like electrodes  4630 ,  4631 , and  4632  respectively. 
     Each of line-like partitions  4650 ,  4651 , and  4652  has a height of 2.0 μm lower than the liquid crystal cell gap. This forms a gap of a height of 1.0 μm between each of the line-like partitions  4650 ,  4651 , and  4652 , and the upper counter substrate  4611 . 
       FIG. 37  is a graph showing response curves obtained by evaluating response characteristics using the structure model in the absence of a partition illustrated in  FIG. 23  and the structure model in the presence of a partition illustrated in  FIG. 36 . 
     The response characteristics were evaluated in the same manner as in the first embodiment. 
     As illustrated in  FIG. 37 , rising and falling of a response curve corresponding to use of the structure model  4600  in the presence of the partition  4624  illustrated in  FIG. 36  are respectively steeper than rising and falling of a response curve corresponding to use of the structure model  2500  in the absence of a partition illustrated in  FIG. 23 . 
     Table 6 shows a rising period and a falling period determined by the use of the structure model  2500  illustrated in  FIG. 23  in the absence of a partition and corresponding periods determined by the use of the structure model  4600  illustrated in  FIG. 36  in the presence of the partition  4624 . 
     
       
         
           
               
             
               
                 TABLE 6 
               
             
            
               
                   
               
               
                 Fourth embodiment 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Electrode 
                 Gap between 
                 Cell 
                 Rising 
                 Falling 
                 Brightness 
               
               
                 System 
                 width 
                 electrodes 
                 gap 
                 period 
                 period 
                 transmittance 
               
               
                   
               
               
                 Without partition 
                 3.0 μm 
                 9.0 μm 
                 3.0 μm 
                 16.4 ms 
                 12.4 ms 
                 66.4% 
               
               
                 With partition 
                 3.0 μm 
                 9.0 μm 
                 3.0 μm 
                 13.0 ms 
                  9.2 ms 
                 44.3% 
               
               
                   
               
            
           
         
       
     
     As understood from Table 6, the falling period determined by the use of the structure model  4600  illustrated in  FIG. 36  in the presence of the partition  4624  is shorter than the falling period determined by the use of the structure model  2500  illustrated in  FIG. 23  in the absence of a partition. 
     5. Fifth Embodiment 
     5.1 Main Difference Between Second Embodiment and Fifth Embodiment 
     A fifth embodiment relates to a liquid crystal display of the horizontal field system. 
     The second embodiment and the fifth embodiment differ from each other mainly in the following. In the second embodiment, the partition  2081  is arranged on the field concentrated parts  2190 ,  2191 ,  2192 , and  2193  at the image signal line slit electrode  2124  and on the field concentrated parts  2200 ,  2201 , and  2202  at the common potential line lower electrode  2125 . In the fifth embodiment, while a partition is arranged on the field concentrated parts  2200 ,  2201 , and  2202  at the common potential line lower electrode  2125 , a partition is not arranged on the field concentrated parts  2190 ,  2191 ,  2192 , and  2193  at the image signal line slit electrode  2124 . Structures or modifications thereof employed in liquid crystal displays of the other embodiments may also be employed in the liquid crystal display of the fifth embodiment within a range in which structures resulting in the foregoing main difference can be employed without any interference. 
     5.2 Liquid Crystal Display, Liquid Crystal Panel, and Display Region of TFT Substrate 
     The schematic view of  FIG. 1  is also a perspective view illustrating the liquid crystal display of the fifth embodiment. The schematic view of  FIG. 2  is also a sectional view illustrating a section of a liquid crystal panel provided in the liquid crystal display of the fifth embodiment. The schematic view of  FIG. 3  is also a plan view illustrating a TFT substrate, a printed board, and an integrated circuit chip provided in the liquid crystal display of the fifth embodiment. 
     5.3 Configuration of TFT Substrate 
     The schematic view of  FIG. 18  is a plan view illustrating planar arrangement of a line, an electrode, and a semiconductor channel layer provided in the liquid crystal display of the fifth embodiment. The schematic view of  FIG. 38  is a plan view illustrating planar arrangement of an organic planarizing film, an electrode, a partition, and an alignment film provided in the liquid crystal display of the fifth embodiment.  FIGS. 39, 40, and 41  are sectional views each illustrating sections of the TFT substrate and a liquid crystal layer provided in the liquid crystal display of the fifth embodiment. 
       FIG. 39  illustrates a section taken at a position along a cutting line A-A′ in FIGS.  18  and  38 .  FIG. 40  illustrates a section taken at a position along a cutting line B-B′ in  FIGS. 18 and 38 .  FIG. 41  illustrates a section taken at a position along a cutting line C-C′ in  FIGS. 18 and 38 . 
       FIGS. 18, 38, 39, 40, and 41  illustrate the each pixel region  1060  illustrated in  FIG. 3 . 
     A TFT substrate  5070  illustrated in  FIGS. 18, 38, 39, 40, and 41  becomes the TFT substrate  1030  illustrated in  FIGS. 1, 2, and 3 . A liquid crystal layer  5071  illustrated in  FIGS. 39, 40, and 41  becomes the liquid crystal layer  1031  illustrated in  FIG. 2   
       FIG. 18  illustrates the image signal line  2100 , the scanning line  2110 , the common potential line  2111 , the scanning line electrode  2120 , the semiconductor channel layer  2121 , the image signal line electrode  2122 , the image signal line electrode  2123 , the image signal line slit electrode  2124 , the common potential line lower electrode  2125 , the image signal line through hole group  2126 , and the common potential line through hole  2127  provided in the TFT substrate  5070 , which are structures corresponding to those of the second embodiment. 
       FIG. 38  illustrates the organic planarizing film  2093  and the image signal line slit electrode  2124  provided in the TFT substrate  5070 , which are structures corresponding to those of the second embodiment.  FIG. 38  further illustrates a partition  5081  and an alignment film  5082  provided in the TFT substrate  4070 . 
       FIG. 39  illustrates the glass substrate  2090 , the scanning line insulating film  2091 , the interlayer insulating film  2092 , the organic planarizing film  2093 , the common potential line  2111 , the scanning line electrode  2120 , the semiconductor channel layer  2121 , the image signal line electrode  2122 , the image signal line electrode  2123 , the image signal line slit electrode  2124 , the common potential line lower electrode  2125 , the image signal line through hole group  2126 , and the common potential line through hole  2127  provided in the TFT substrate  5070 , which are structures corresponding to those of the second embodiment.  FIG. 39  further illustrates an alignment film  5094  provided in the TFT substrate  5070 . 
       FIG. 40  illustrates the glass substrate  2090 , the scanning line insulating film  2091 , the interlayer insulating film  2092 , the organic planarizing film  2093 , the image signal line  2100 , the scanning line  2110 , the common potential line  2111 , and the common potential line lower electrode  2125  provided in the TFT substrate  5070 , which are structures corresponding to those of the second embodiment.  FIG. 40  further illustrates the alignment film  5094 , the partition  5081 , and the alignment film  5082  provided in the TFT substrate  5070 . 
       FIG. 41  illustrates the glass substrate  2090 , the scanning line insulating film  2091 , the interlayer insulating film  2092 , the organic planarizing film  2093 , the image signal line slit electrode  2124 , and the common potential line lower electrode  2125  provided in the TFT substrate  5070 , which are structures corresponding to those of the second embodiment.  FIG. 41  further illustrates the alignment film  5094 , the partition  5081 , and the alignment film  5082  provided in the TFT substrate  5070 . 
     The scanning line insulating film  2091 , the scanning line electrode  2120 , the semiconductor channel layer  2121 , the image signal line electrode  2122 , and the image signal line electrode  2123  form a TFT. The image signal line slit electrode  2124  and the common potential line lower electrode  2125  form a pixel electrode. 
     The common potential line lower electrode  2125  includes the sheet-like electrode  2160  illustrated in  FIGS. 18, 39, 40, and 41 , which is a structure corresponding to that of the second embodiment. The image signal line slit electrode  2124  includes the line-like electrodes  2150 ,  2151 ,  2152 , and  2153  illustrated in  FIGS. 18 and 41 , which are structures corresponding to those of the second embodiment. 
     As illustrated in  FIGS. 39, 40, and 41 , the alignment film  5094  is stacked on the organic planarizing film  2093  and the image signal line slit electrode  2124  and arranged over the upper main surface  2130  of the glass substrate  2090 . The alignment film  5094  has an upper main surface  5140  forming the upper main surface of the TFT substrate  5070  and contacting the liquid crystal layer  5071 . The upper main surface  5140  of the alignment film  5094  is subjected to alignment process by means of a rubbing or photo-alignment method, for example. Thus, the upper main surface  5140  of the alignment film  5094  has an alignment capability of aligning liquid crystal molecules in the liquid crystal layer  5071  in a particular alignment direction. 
     The partition  5081  desirably has a height of two-thirds or more of a liquid crystal cell gap as a gap between a part of the TFT substrate  5070  other than the partition  5081  and the alignment film  5082 , and the CF substrate  1032 . 
     5.4 Generation of Horizontal Field 
     Like in the second embodiment, in response to application of an ON signal to the scanning line electrode  2120  illustrated in  FIGS. 18 and 39 , a driving voltage is applied between the image signal line slit electrode  2124  illustrated in  FIGS. 18, 38, 39, and 41  and the common potential line lower electrode  2125  illustrated in  FIGS. 18, 39, 40, and 41 . 
     When the driving voltage is applied between the image signal line slit electrode  2124  as a first pixel electrode and the common potential line lower electrode  2125  as a second pixel electrode, the common potential line lower electrode  2125  becomes involved in a field from the image signal line slit electrode  2124 . More specifically, as illustrated in  FIG. 41 , a fringe field is generated between the field concentrated part  2200  as a second field concentrated part occupying a part of the upper main surface of the sheet-like electrode  2160 , and the field concentrated parts  2190  and  2191  as a first field concentrated part respectively occupying substantially entire upper surfaces of the line-like electrodes  2150  and  2151  adjacent to the field concentrated part  2200 . As illustrated in  FIG. 41 , a fringe field is generated between the field concentrated part  2201  as the second field concentrated part occupying a part of the upper main surface of the sheet-like electrode  2160 , and the field concentrated parts  2191  and  2192  as the first field concentrated part respectively occupying substantially entire upper surfaces of the line-like electrodes  2151  and  2152  adjacent to the field concentrated part  2201 . Further, as illustrated in  FIG. 41 , a fringe field is generated between the field concentrated part  2202  as the second field concentrated part occupying a part of the upper main surface of the sheet-like electrode  2160 , and the field concentrated parts  2192  and  2193  as the first field concentrated part respectively occupying substantially entire upper surfaces of the line-like electrodes  2152  and  2153  adjacent to the field concentrated part  2202 . Each of the field concentrated parts  2200 ,  2201 , and  2202  has a line-like planar shape as viewed in the thickness direction of the TFT substrate  5070  and extends in an extension direction indicated by the arrow AY. As illustrated in  FIG. 41 , the field concentrated parts  2200 ,  2201 , and  2202  are arranged in a direction indicated by the arrow AX. As illustrated in  FIG. 41 , the field concentrated part  2200  is at an intermediate position between the line-like electrode  2150  and the line-like electrode  2151 . The field concentrated part  2201  is at an intermediate position between the line-like electrode  2151  and the line-like electrode  2152 . The field concentrated part  2202  is at an intermediate position between the line-like electrode  2152  and the line-like electrode  2153 . The generated fringe fields pass through the liquid crystal layer  5071 , as indicated by the electric lines of force  2210  illustrated in  FIG. 41 . 
     5.5 Partition 
     The partition  5081  includes a line-like partition  5230 , a line-like partition  5231 , and a line-like partition  5232  illustrated in  FIGS. 38 and 41 . The line-like partitions  5230 ,  5231 , and  5232  are arranged between the line-like electrodes  2150 ,  2151 ,  2152 , and  2153  and extend in a direction substantially parallel to the direction of the alignment film  5094 . As illustrated in  FIG. 38 , each of the line-like partitions  5230 ,  5231 , and  5232  has a line-like planar shape as viewed in the thickness direction of the TFT substrate  5070  and extends in the extension direction indicated by the arrow AY, like each of the field concentrated parts  2200 ,  2201 , and  2202 . As illustrated in  FIG. 41 , the line-like partitions  5230 ,  5231 , and  5232  are arranged on the field concentrated parts  2200 ,  2201 , and  2202  respectively. As illustrated in  FIG. 41 , each of the line-like partitions  5230 ,  5231 , and  5232  partitions the liquid crystal layer  5071  in a partitioning direction indicated by the arrow AX. 
     Meanwhile, as illustrated in  FIG. 41 , a line-like partition is not arranged on the field concentrated parts  2190 ,  2191 ,  2192 , and  2193 . 
     The alignment film  5082  includes a line-like alignment film  5260 , a line-like alignment film  5261 , and a line-like alignment film  5262  illustrated in  FIGS. 38 and 41 . As illustrated in  FIGS. 38 and 41 , the line-like alignment films  5260 ,  5261 , and  5262  cover the line-like partitions  5230 ,  5231 , and  5232  respectively. As illustrated in  FIGS. 40 and 41 , the alignment film  5082  has a surface  5270  contacting the liquid crystal layer  5071 . The surface  5270  of the alignment film  5082  is subjected to alignment process by means of a rubbing or photo-alignment method, for example. Thus, the surface  5270  of the alignment film  5082  has an alignment capability of aligning liquid crystal molecules in the liquid crystal layer  5071  in a particular alignment direction. A direction in which liquid crystal molecules are aligned in the surface  5270  of the alignment film  5082  as a second alignment film agrees with a direction in which liquid crystal molecules are aligned in the upper main surface  5140  of the alignment film  5094  as a first alignment film. The alignment film  5082  is desirably a photo-alignment film subjected to alignment process by means of a photo-alignment method. 
     Like in the second embodiment, a line-like partition having a forward tapered shape may be used as an alternative, Further, a line-like electrode or a line-like partition further functioning as a light shield may be used as an alternative. 
     5.6 Analysis of Response Speed During Falling Time by Simulation 
     In the following description, response speed during the falling time in the presence of a partition such as the partition  5081  is analyzed by simulation to show that response time during the falling time in the presence of a partition such as the partition  5081  is shorter than response time during the falling time in the absence of a partition such as the partition  5081 . 
     A used simulator is LCDMaster 2D (Ver. 8.5.2) available from SHINTECH, Inc. Table 1 given above shows the physical property values of the liquid crystal material MS-5355XX-K forming a liquid crystal layer in a structure model used in the simulation. Table 2 given above shows common parameters common to structure models used in the simulation. The structure models used in the simulation were simplified to a maximum within a range in which the appropriateness of the structure models can be guaranteed. 
       FIG. 42  is a sectional view illustrating a section of a structure model used for analyzing response speed during the falling time by simulation in the presence of a partition. 
     A structure model  5600  illustrated in  FIG. 42  is produced by modeling a minimum recurring unit of a liquid crystal cell of the FFS system to which partition is added, and includes a lower substrate  5610 , an upper counter substrate  5611 , and a liquid crystal layer  5612 . The lower substrate  5610  includes a lower glass substrate  5620 , an organic planarizing film  5621 , an image signal line slit electrode  5622 , a common potential line lower electrode  5623 , and a partition  5624 . The image signal line slit electrode  5622  includes a line-like electrode  5630 , a line-like electrode  5631 , and a line-like electrode  5632 . The common potential line lower electrode  5623  includes a sheet-like electrode  5640 . The partition  5624  includes a line-like partition  5650  and a line-like partition  5651 . 
     The liquid crystal material MS-5355XX-K is poured in between an upper main surface  5670  of the lower substrate  5610  and a lower main surface  5671  of the upper counter substrate  5611  to form the liquid crystal layer  5612  made of the liquid crystal material MS-5355XX-K. An alignment film not illustrated covering the upper main surface  5670  of the lower substrate  5610  is subjected to alignment process for aligning liquid crystal molecules in the liquid crystal layer  5612  in a first direction. An alignment film not illustrated covering the lower main surface  5671  of the upper counter substrate  5611  is subjected to alignment process for aligning the liquid crystal molecules in the liquid crystal layer  5612  in a second direction perpendicular to the first direction. Each of the line-like electrodes  5630 ,  5631 , and  5632  has a width of 3.0 μm. A gap between two adjacent ones of the line-like electrodes  5630 ,  5631 , and  5632  is 9.0 μm. A liquid crystal cell gap is 3.0 μm. 
     As illustrated in  FIG. 42 , the line-like partition  5650  is arranged on a field concentrated part  5680  at an intermediate position between the position of the line-like electrode  5630  and the position of the line-like electrode  5631 . The line-like partition  5651  is arranged on a field concentrated part  5681  at an intermediate position between the position of the line-like electrode  5631  and the position of the line-like electrode  5632 . Each of line-like partitions  5650  and  5651  has a width of 3.0 μm and a height of 2.0 μm lower than the liquid crystal cell gap. This forms a gap of a height of 1.0 μm between each of the line-like partitions  5650  and  5651 , and the upper counter substrate  5611 . 
       FIG. 43 . is a graph showing response curves obtained by evaluating response characteristics using the structure model in the absence of a partition illustrated in  FIG. 23  and the structure model in the presence of a partition illustrated in  FIG. 42 . 
     The response characteristics were evaluated in the same manner as in the first embodiment. 
     As illustrated in  FIG. 43 , rising and falling of a response curve corresponding to use of the structure model  5600  in the presence of the partition  5624  illustrated in  FIG. 42  are respectively steeper than rising and falling of a response curve corresponding to use of the structure model  2500  in the absence of a partition illustrated in  FIG. 23 . 
     Table 7 shows a rising period and a falling period determined by the use of the structure model  2500  illustrated in  FIG. 23  in the absence of a partition and corresponding periods determined by the use of the structure model  5600  illustrated in  FIG. 42  in the presence of the partition  5624 . 
     
       
         
           
               
             
               
                 TABLE 7 
               
             
            
               
                   
               
               
                 Fifth embodiment 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Electrode 
                 Gap between 
                 Cell 
                 Rising 
                 Falling 
                 Brightness 
               
               
                 System 
                 width 
                 electrodes 
                 gap 
                 period 
                 period 
                 transmittance 
               
               
                   
               
               
                 Without partition 
                 3.0 μm 
                 9.0 μm 
                 3.0 μm 
                 16.4 ms 
                 12.4 ms 
                 66.4% 
               
               
                 With partition 
                 3.0 μm 
                 9.0 μm 
                 3.0 μm 
                 11.4 ms 
                 10.6 ms 
                 46.2% 
               
               
                   
               
            
           
         
       
     
     As understood from Table 7, the falling period determined by the use of the structure model  5600  illustrated in  FIG. 42  in the presence of the partition  5624  is shorter than the falling period determined by the use of the structure model  2500  illustrated in  FIG. 23  in the absence of a partition. 
     6. Sixth Embodiment 
     6.1 Main Difference Between Second Embodiment and Sixth Embodiment 
     A sixth embodiment relates to a liquid crystal display of the horizontal field system. 
     The second embodiment and the sixth embodiment differ from each other mainly in the following. In the second embodiment, the liquid crystal layer  2071  is made of positive-type liquid crystal. By contrast, in the sixth embodiment, a liquid crystal layer is made of negative-type liquid crystal. Structures or modifications thereof employed in liquid crystal displays of the other embodiments may also be employed in the liquid crystal display of the sixth embodiment within a range in which structures resulting in the foregoing main difference can be employed without any interference. 
     6.2 Liquid Crystal Display 
     The liquid crystal display of the sixth embodiment is the same as the liquid crystal display of the second embodiment except that the liquid crystal layer  2071  made of positive-type liquid crystal is replaced with a liquid crystal layer made of negative-type liquid crystal. Further, a partition extends in a direction along a lower polarizing axis. 
     The theoretical analysis of response speed during the falling time described in the first embodiment shows that replacing the liquid crystal layer  2071  made of positive-type liquid crystal with a liquid crystal layer made of negative-type liquid crystal merely results in change in an initial alignment direction by 90°, so that shortening of response time using a partition is still expected. This also applies to a case where the liquid crystal layer made of positive-type liquid crystal provided in each of the first and third to fifth embodiments is replaced with a liquid crystal layer made of negative-type liquid crystal. 
     6.3 Analysis of Response Speed During Falling Time by Simulation 
     The following describes analysis of response speed during the falling time by the simulation described in the second embodiment conducted after replacing a liquid crystal layer made of positive-type liquid crystal with a liquid crystal layer made of negative-type liquid crystal. 
     A used simulator is LCDMaster 2D (Ver. 8.5.2) available from SHINTECH, Inc. Table 8 shows the physical property values of a liquid crystal material forming a liquid crystal layer in a structure model used in the simulation. Table 2 given above shows common parameters common to structure models used in the simulation with exception that a rubbing angle and a lower polarizing axis angle is changed from 83° to − 7 . 
     
       
         
           
               
               
               
               
             
               
                 TABLE 8 
               
               
                   
               
               
                   
                 Wavelength 
                   
                   
               
               
                   
                 (nm) 
                 Ordinary light (no) 
                 Extraordinary light (ne) 
               
               
                   
               
             
            
               
                 Refractive index 
                 450 
                 1.504 
                 1.638 
               
               
                   
                 550 
                 1.492 
                 1.614 
               
               
                   
                 650 
                 1.486 
                 1.602 
               
            
           
           
               
               
               
            
               
                 Relative 
                 εp 
                 2.9 
               
               
                 permittivity 
                 εs 
                 7.5 
               
               
                 Elastic constant 
                 K11 
                 14.6 
               
               
                 (pN) 
                 K22 
                 9.8 
               
               
                   
                 K33 
                 19.1 
               
               
                 Viscosity 
                 γ1 
                 0.099 
               
               
                 constant (Pa · s) 
                   
                   
               
               
                   
               
            
           
         
       
     
       FIG. 44  is a graph showing response curves resulting from replacement of a liquid crystal layer made of positive-type liquid crystal with a liquid crystal layer made of negative-type liquid crystal and obtained by evaluating response characteristics using the structure model  2500  illustrated in  FIG. 23  and the structure model  2600  illustrated in FIG.  24 . 
     As shown in  FIG. 44 , rising and falling of a response curve corresponding to use of the structure model  2600  illustrated in  FIG. 24  are respectively steeper than rising and falling of a response curve corresponding to use of the structure model  2500  illustrated in  FIG. 23 . 
     Table 9 shows a rising period and a falling period determined by the use of the structure model  2500  illustrated in  FIG. 23  and corresponding periods determined by the use of the structure model  2600  illustrated in  FIG. 24 . 
     
       
         
           
               
             
               
                 TABLE 9 
               
             
            
               
                   
               
               
                 Sixth embodiment 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Electrode 
                 Gap between 
                 Cell 
                 Rising 
                 Falling 
                 Brightness 
               
               
                 System 
                 width 
                 electrodes 
                 gap 
                 period 
                 period 
                 transmittance 
               
               
                   
               
               
                 Without partition 
                 3.0 μm 
                 9.0 μm 
                 3.0 μm 
                 15.0 ms 
                 13.0 ms 
                 56.1% 
               
               
                 With partition 
                 3.0 μm 
                 9.0 μm 
                 3.0 μm 
                  6.4 ms 
                  4.4 ms 
                 30.3% 
               
               
                   
               
            
           
         
       
     
     As understood from Table 9, the falling period determined by the use of the structure model  2600  illustrated in  FIG. 24  is about one-third of the falling period determined by the use of the structure model  2500  illustrated in  FIG. 23 . 
     The embodiments of the present invention can be combined freely, and each embodiment can be modified or omitted, where appropriate, within a range of the invention. 
     While the invention has been shown and described in detail, the foregoing description is in all aspects illustrative and does not restrict the invention. It is therefore understood that numerous modifications not illustrated can be devised without departing from the scope of the invention. 
     EXPLANATION OF REFERENCE SIGNS 
       1124 ,  2124  Image signal line slit electrode,  1125  Common potential line slit electrode,  2125  Common potential line lower electrode,  1081 ,  2081 ,  3081 ,  4081 ,  5081  Partition,  1071 ,  2071 ,  3071 ,  4071 ,  5071  Liquid crystal layer