Abstract:
The first substrate has a first projection in which a first part extending along a side of the first substrate in the peripheral part of the first substrate and a second part extending from the first part towards an edge of the first substrate are formed. Width of a cross section of the first projection is smaller on its tip end&#39;s side than on the first substrate&#39;s side. The second substrate has a second projection extending along a side of the second substrate in the peripheral part of the second substrate. Width of a cross section of the second projection is smaller on its tip end&#39;s side than on the second substrate&#39;s side. The second part of the first projection faces the second projection. The seal member exists between the first projection and the second projection.

Description:
CLAIM OF PRIORITY 
       [0001]    The present application claims priority from Japanese Patent Application JP 2015-253793 filed on Dec. 25, 2015, the content of which is hereby incorporated by reference into this application. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a display device, and in particular, to a liquid crystal display device capable of securing the reliability of a seal part even when a frame region is narrowed. 
         [0004]    2. Description of the Related Art 
         [0005]    In a liquid crystal display device, a thin-film transistor (TFT) substrate on which pixels each having pixel electrodes, a TFT, etc. are formed like a matrix and a counter substrate are arranged to face each other and a liquid crystal is sandwiched between the TFT substrate and the counter substrate. The liquid crystal display device forms an image by controlling the light transmittance of liquid crystal molecules in regard to each pixel. 
         [0006]    Especially with middle-sized and small-sized liquid crystal display devices, there is a strong demand to enlarge the display region while maintaining small exterior size of the display device. Accordingly, the region between the display region and the edge of the liquid crystal display panel, namely, the frame region, becomes narrower and narrower. The liquid crystal is sealed up in a space between the TFT substrate and the counter substrate by use of a seal member formed in the frame region. The seal member is applied by using a dispenser and thereafter hardened by using heat or ultraviolet rays. 
         [0007]    With the decrease in the width of the seal member, uniformly forming the seal member becomes difficult and reliability of the seal part becomes an issue. Further, if the seal member before hardening makes contact with the liquid crystal, the seal member can contaminate the liquid crystal and cause a drop in the resistivity of the liquid crystal. 
         [0008]    JP-A-2009-133930 describes a configuration in which a line-shaped spacer is formed on the TFT substrate&#39;s side and on the counter substrate&#39;s side and the line-shaped spacers are arranged in the seal member in order to secure an appropriate width of the seal member. JP-A-2004-133194 describes a configuration in which an anti-diffusion wall is formed to reduce the area of contact between the seal member and the liquid crystal. JP-A-2013-190551 describes a configuration in which an inner projection and an outer projection are respectively arranged along the inner edge and the outer edge of the seal member in order to precisely determine the distance between the TFT substrate and the counter substrate. 
       SUMMARY OF THE INVENTION 
       [0009]    The demand for narrowing the frame region is growing, and accordingly, decreasing the width of the seal member is also being demanded. However, with the decrease in the width of the seal member, variations in the application of the seal member can cause extremely narrow parts of the seal member or interruption of the seal member depending on the case. Further, due to the narrow frame region, locally widened parts of the seal member can protrude into the display region. 
         [0010]    With the increase in the screen resolution, abnormality such as color irregularity due to variations in the distance between the TFT substrate and the counter substrate becomes more likely to occur. Such variations in the distance between the TFT substrate and the counter substrate can occur also in the seal part. Then, the influence of the variations can reach the display region and deteriorate the image quality in peripheral parts of the screen. 
         [0011]    Recently, the liquid dropping method is commonly used as the method for injecting the liquid crystal into the internal space of the liquid crystal display panel. In this method, the liquid crystal is dropped into the internal space before the seal member hardens. Thus, the liquid crystal, making contact with the seal member before hardening, is likely to be contaminated by the seal member. The object of the present invention is to secure the reliability of the seal part, restrain the deterioration in the image quality in the peripheral parts of the display region, and reduce the degradation of the liquid crystal due to the influence of the seal member even when the frame region is narrowed. 
         [0012]    The present invention solves the problems described above, and its specific solution is as follows. 
         [0013]    In accordance with an aspect of the present invention, there is provided a liquid crystal display device including a first substrate and a second substrate bonded to each other at their peripheral parts by using a seal member and a liquid crystal sealed up in a space between the first substrate and the second substrate. The first substrate has a first projection in which a first part extending along a side of the first substrate in the peripheral part of the first substrate and a second part extending from the first part towards an edge of the first substrate are formed. Width of a cross section of the first projection is smaller on its tip end&#39;s side than on the first substrate&#39;s side. The second substrate has a second projection extending along a side of the second substrate in the peripheral part of the second substrate. Width of a cross section of the second projection is smaller on its tip end&#39;s side than on the second substrate&#39;s side. The second part of the first projection faces the second projection. The seal member exists between the first projection and the second projection. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a plan view showing an example of a liquid crystal display device to which the present invention is applied. 
           [0015]      FIG. 2A  is a schematic diagram showing problems occurring when the width of a seal part is reduced. 
           [0016]      FIG. 2B  is a schematic diagram showing another problems occurring when the width of a seal part is reduced. 
           [0017]      FIG. 3  is a plan view showing a liquid crystal display device according to a first embodiment of the present invention. 
           [0018]      FIG. 4  is a perspective view showing the relationship between a first projection and a second projection. 
           [0019]      FIG. 5  is an enlarged plan view of the part A in  FIG. 3 . 
           [0020]      FIG. 6  is a cross-sectional view taken along the line A-A in  FIG. 5 . 
           [0021]      FIG. 7  is a cross-sectional view taken along the line B-B in  FIG. 5 . 
           [0022]      FIG. 8A  is a schematic plan view showing a process for carrying out the present invention in a counter substrate. 
           [0023]      FIG. 8B  is a schematic plan view showing a process for carrying out the present invention in a TFT substrate. 
           [0024]      FIG. 9A  is a schematic plan view showing another process for carrying out the present invention in a counter substrate. 
           [0025]      FIG. 9B  is a schematic plan view showing another process for carrying out the present invention in a TFT substrate. 
           [0026]      FIG. 10  is a cross-sectional view showing another example of the liquid crystal display device according to this embodiment. 
           [0027]      FIG. 11  is a cross-sectional view showing still another example of the liquid crystal display device according to this embodiment. 
           [0028]      FIG. 12  is a plan view showing a liquid crystal display device according to a second embodiment of the present invention. 
           [0029]      FIG. 13  is a perspective view showing the relationship between a first projection and second projections in the second embodiment. 
           [0030]      FIG. 14  is an enlarged plan view of the part B in  FIG. 12 . 
           [0031]      FIG. 15  is a cross-sectional view taken along the line C-C in  FIG. 14 . 
           [0032]      FIG. 16  is a cross-sectional view taken along the line D-D in  FIG. 14 . 
           [0033]      FIG. 17  is a plan view showing a liquid crystal display device according to a third embodiment of the present invention. 
           [0034]      FIG. 18  is a perspective view showing the relationship between a first projection and a second projection in the third embodiment. 
           [0035]      FIG. 19  is an enlarged plan view of the part C in  FIG. 17 . 
           [0036]      FIG. 20  is a cross-sectional view taken along the line E-E in  FIG. 19 . 
           [0037]      FIG. 21  is a cross-sectional view taken along the line F-F in  FIG. 19 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0038]      FIG. 1  is a plan view showing an example of a liquid crystal display device to which the present invention is applied. In  FIG. 1 , a TFT substrate  100  on which scan lines  50  and video signal lines  60  have been formed and a counter substrate  200  are bonded to each other with a seal member  150  formed in a peripheral part, and a liquid crystal is held in a space between the TFT substrate  100  and the counter substrate  200 . A display region  80  is formed in a part where the TFT substrate  100  and the counter substrate  200  overlap each other, and a frame region is formed outside the display region  80 . 
         [0039]    The TFT substrate  100  is formed to be larger than the counter substrate  200 . A part of the TFT substrate  100  not paired with the counter substrate  200  is formed as a terminal unit  160 . In the terminal unit  160 , terminals for supplying scan signals, video signals, electric power, etc. to the display region  80  are formed and an IC driver for driving the liquid crystal is arranged. Further, a so-called flexible wiring board is connected to the terminal unit  160  in order to supply signals and electric power from the outside. 
         [0040]    In the display region  80  shown in  FIG. 1 , a plurality of scan lines  50  extending in a horizontal direction are arranged in a vertical direction. Further, a plurality of video signal lines  60  extending in the vertical direction are arranged in the horizontal direction. The scan signals, video signals, etc. are supplied from the terminal unit  160 . Each pixel  70  is formed as a region surrounded by scan lines  50  and video signal lines  60 . Each pixel  70  includes a TFT and pixel electrodes. In recent years, narrowing the frame region is being demanded and the width wa shown in  FIG. 1  has decreased to approximately 0.5 mm. Accordingly, the seal member  150  formed in the frame region is also being narrowed and the width wb shown in  FIG. 1  has decreased to approximately 0.3 mm. 
         [0041]    While the seal member  150  is applied by using a dispenser, variations in the application greatly affects the reliability of the seal part in cases where the width of the seal member  150  is reduced.  FIG. 2A  shows an example in which a part of the seal member  150  has narrowed and interrupted. Although such interruption never occurs if the width of the seal member  150  is originally large, the phenomenon like that shown in  FIG. 2A  is caused by the reduction in the width of the seal member  150 . 
         [0042]      FIG. 2B  shows an example in which the position of applying the seal member  150  fluctuated in a certain part, the width of the seal member  150  increased in the part, and the seal member  150  protruded into the display region  80 . Such a phenomenon hardly occurs when the frame region is wide. However, the narrowing of the frame region has facilitated the occurrence of the phenomenon. Incidentally, while there are cases where the seal member is applied by means of printing or the like, similar problems occur even in such cases. One of the objects of the present invention is to prevent such phenomena. Embodiments according to the present invention will be described in detail below. 
       First Embodiment 
       [0043]      FIG. 3  is a schematic plan view showing a liquid crystal display device according to a first embodiment of the present invention. In  FIG. 3 , the counter substrate  200  is arranged over the TFT substrate  100  and the liquid crystal is sealed up in a space between the TFT substrate  100  and the counter substrate  200 . On the counter substrate  200 &#39;s side of the seal part, a projection  10 , having parts in T-shapes in the plan view, is formed throughout the periphery of the counter substrate  200 . This projection  10  will hereinafter be referred to as a “T-shaped projection  10 ” since the projection  10  has parts in T-shapes in the plan view. On the TFT substrate  100 &#39;s side, a projection  20  is formed like a frame in the peripheral part of the TFT substrate  100 . This projection  20  will hereinafter be referred to as a “frame-shaped projection  20 .” Illustration of the seal member is omitted in  FIG. 3  to avoid complication of the drawing. 
         [0044]      FIG. 4  is a perspective view of the part A in  FIG. 3 . Illustration of the seal member is omitted in  FIG. 4  to facilitate the understanding of the drawing. In  FIG. 4 , the T-shaped projection  10  is formed on the counter substrate  200 &#39;s side and the frame-shaped projection  20  is formed on the TFT substrate  100 &#39;s side. Both of the T-shaped projection  10  and the frame-shaped projection  20  have triangular cross sections. The T-shaped projection  10  and the frame-shaped projection  20  are in contact with each other at apices of their triangles. In  FIG. 4 , the sum h 1 +h 2  of the height h 1  of the T-shaped projection  10  and the height h 2  of the frame-shaped projection  20  equals the distance between the TFT substrate  100  and the counter substrate  200 . The heights h 1  and h 2  satisfy h 1 =h 2  in many cases. In such cases, suppose the distance between the TFT substrate  100  and the counter substrate  200  is 3 μm, each of h 1  and h 2  is approximately 1.5 μm. As above, the T-shaped projection  10  and the frame-shaped projection  20  also have the function of spacers in the seal part. 
         [0045]    The width of a base part of each of the T-shaped projection  10  and the frame-shaped projection  20  will hereinafter be referred to simply as “width.” The width w 11  of a part of the T-shaped projection  10  extending in a direction parallel to a side of the counter substrate  200 , the width w 1  of a part of the T-shaped projection  10  extending in a direction orthogonal to the side of the counter substrate  200 , and the width w 2  of the base part of the frame-shaped projection  20  (hereinafter referred to simply as “widths”) are approximately 15 μm, for example. Since the width of the seal member is approximately 300 μm, the widths w 1 , w 11  and w 2  are negligible in comparison with the width of the seal member. Incidentally, the width w 5  of the T-shaped projection  10  measured in the direction orthogonal to the side of the counter substrate  200  can be approximately equal to or smaller than the width of the seal member. Both the T-shaped projection  10  and the frame-shaped projection  20  can be formed in precise dimensions since the projections  10  and  20  are formed by means of photolithography. 
         [0046]      FIG. 5  is a plan view of the part A in  FIG. 3 . In  FIG. 5 , the part A is viewed from the counter substrate  200 &#39;s side. The T-shaped projection  10  is formed on the counter substrate  200 &#39;s side, while the frame-shaped projection  20  is formed on the TFT substrate  100 &#39;s side. The dotted line at the center of the T-shaped projection  10  indicates the top apex of the triangle of the T-shaped projection  10 . The dotted line is used since the top apex of the triangle is situated on the back side in the plan view. The line at the center of the frame-shaped projection  20  indicates the top apex of the triangle of the frame-shaped projection  20 . The seal member  150  is filled in between the T-shaped projection  10  and the frame-shaped projection  20 . The left-hand side of  FIG. 5  is the display region  80 , in which columnar spacers  204  for maintaining the distance between the TFT substrate  100  and the counter substrate  200  are formed. 
         [0047]      FIG. 6  is a cross-sectional view taken along the line A-A in  FIG. 5 . In  FIG. 6 , an organic passivation film  101  is formed on the TFT substrate  100 . The organic passivation film  101  is formed with transparent resin such as acrylic, for example. While other layers such as TFTs and an insulation film are formed under the organic passivation film  101 , such layers are omitted in  FIG. 6  to avoid complication of the drawing. The organic passivation film  101  is used not only to protect the TFTs but also as a planarization film, and thus is formed to be as thick as approximately 1-4 μm. An inorganic insulation film  102  is formed on the organic passivation film  101 . The frame-shaped projection  20  is formed on the inorganic insulation film  102 . 
         [0048]    In  FIG. 6 , the counter substrate  200  is arranged to oppose the TFT substrate  100 . On the counter substrate  200 , a black matrix  201  to serve as a light blocking film is formed in the seal part, while color filters  202  are formed in the display region  80 . An overcoat film  203  is formed to cover the black matrix  201  and the color filters  202 . On the overcoat film  203 , the T-shaped projection  10  is formed in the seal part, while the columnar spacers  204  are formed in the display region  80 . The TFT substrate  100  and the counter substrate  200  are bonded to each other with the seal member  150 . 
         [0049]    In  FIG. 6 , the space on the inside of the seal member  150  is filled with the liquid crystal  300 . Although alignment layers are formed on the TFT substrate  100 &#39;s side and the counter substrate  200 &#39;s side for the initial alignment of molecules of the liquid crystal  300 , the alignment layers are omitted in  FIG. 6  to avoid complication of the drawing. As shown in  FIG. 6 , the distance between the TFT substrate  100  and the counter substrate  200  in the seal part is determined by the T-shaped projection  10  and the frame-shaped projection  20 . In the display region  80 , the distance is determined by the columnar spacers  204 . 
         [0050]    In this embodiment, the liquid crystal  300  is fed into the internal space between the TFT substrate  100  and the counter substrate  200  by the liquid dropping method. However, the seal member  150  has not hardened yet when the liquid crystal is dropped. If the liquid crystal  300  makes contact with the seal member  150  not hardened yet, constituents of the seal member  150  can dissolve in the liquid crystal  300  and deteriorate the properties of the liquid crystal. In this embodiment, the area of contact between the seal member  150  and the liquid crystal is reduced by the presence of the T-shaped projection  10  as shown in  FIG. 6 . Thus, the possibility of the contamination of the liquid crystal by the seal member  150  before hardening is lowered in comparison with the conventional structure. 
         [0051]      FIG. 7  is a cross-sectional view taken along the line B-B in  FIG. 5 .  FIG. 7  is identical with  FIG. 6  except for the seal part. In  FIG. 7 , the seal member  150  bonds the TFT substrate  100  and the counter substrate  200  to each other. The dotted line of the T-shaped projection  10  indicates that the T-shaped projection  10  lies behind the illustrated part of the seal member  150 . As shown in  FIG. 7 , the contact area of the seal member  150  is increased by the contact with the slope  11  of the triangle of the T-shaped projection  10  and the contact with the slopes  21  of the triangle of the frame-shaped projection  20 , and thus the adhesivity by the seal member  150  can be increased and the reliability of the seal part is improved. The rest of the configuration is identical with that explained referring to  FIG. 6 . 
         [0052]      FIGS. 8A and 8B  are schematic diagrams for explaining a production method in the present invention by taking the configuration of the first embodiment as an example.  FIG. 8A  shows the counter substrate  200 &#39;s side, while  FIG. 8B  shows the TFT substrate  100 &#39;s side. In  FIG. 8A , the T-shaped projection  10  is formed on the counter substrate  200 &#39;s side. The T-shaped projection  10  can be formed concurrently with the formation of the columnar spacers in the display region by using the same material. Since the height of the T-shaped projection  10  is less than that of the columnar spacers, the T-shaped projection  10  can be formed by using half exposure technology, for example. 
         [0053]    The T-shaped projection  10  can also be formed during the formation of the overcoat film  203 , by increasing the film thickness of a part of the overcoat film  203  corresponding to the T-shaped projection  10  compared to other regions by using the half exposure technology. Thereafter, the seal member  150  is applied on the T-shaped projection  10  by using the dispenser. Thereafter, the liquid crystal  301  is dropped into the region surrounded by the T-shaped projection  10 . In this state, the seal member  150  has not hardened yet. However, the contamination of the liquid crystal  301  by the seal member  150  can be restrained since the liquid crystal  301  and the seal member  150  are separated from each other by the T-shaped projection  10 . 
         [0054]      FIG. 8B  shows a state in which the frame-shaped projection  20  has been formed on the TFT substrate  100 &#39;s side. The frame-shaped projection  20  can be formed on the inorganic insulation film  102  with the same material as the organic passivation film  101 , for example. However, other organic materials are also usable. The frame-shaped projection  20  can also be formed by increasing the film thickness of a part of the organic passivation film  101  corresponding to the frame-shaped projection  20  compared to other regions by using the half exposure technology. 
         [0055]    Thereafter, the TFT substrate  100  and the counter substrate  200  are bonded to each other via the seal member  150 . In this case, the seal member  150  is pressed and widened by the T-shaped projection  10  and the frame-shaped projection  20 , and thus the interruption of the seal member  150  like that shown in  FIG. 2A  can be prevented. Further, the protrusion of the seal member  150  into the display region  80  like that shown in  FIG. 8B  can be restrained by the presence of the T-shaped projection  10 . Furthermore, outward protrusion of the seal member  150  can also be restrained thanks to the presence of the frame-shaped projection  20 . 
         [0056]      FIGS. 9A and 9B  show another example of the production method in the present invention.  FIG. 9A  shows the counter substrate  200 &#39;s side, while  FIG. 9B  shows the TFT substrate  100 &#39;s side.  FIGS. 9A and 9B  differ from  FIGS. 8A and 8B  in that the frame-shaped projection  20  is formed on the counter substrate  200 &#39;s side and the T-shaped projection  10  is formed on the TFT substrate  100 &#39;s side in  FIGS. 9A and 9B . The T-shaped projection  10  on the TFT substrate  100  can be formed by a method similar to that explained referring to  FIGS. 8A and 8B . In  FIGS. 9A and 9B , the seal member  150  is formed and the liquid crystal  301  is dropped on the TFT substrate  100 &#39;s side. 
         [0057]    On the other hand, the frame-shaped projection  20  is formed on the counter substrate  200 &#39;s side. The frame-shaped projection  20  in this example can be formed by a method similar to the formation of the T-shaped projection  10  explained referring to  FIGS. 8A and 8B . Thereafter, the TFT substrate  100  and the counter substrate  200  are bonded to each other via the seal member  150 . In this case, the seal member  150  is pressed and widened by the T-shaped projection  10  and the frame-shaped projection  20 , and thus the interruption of the seal member  150  like that shown in  FIG. 2A  can be prevented. Further, the protrusion of the seal member  150  into the display region  80  like that shown in  FIG. 2B  can be restrained by the presence of the T-shaped projection  10 . Furthermore, outward protrusion of the seal member  150  can also be restrained thanks to the presence of the frame-shaped projection  20 . 
         [0058]    While the above explanation has been given assuming that the cross sections of the T-shaped projection  10 , the frame-shaped projection  20 , the columnar spacer  204 , etc. are in triangular shapes, the present invention is not to be restricted to such examples.  FIG. 10  shows a case where the cross sections of the T-shaped projection  10 , the frame-shaped projection  20 , the columnar spacer  204 , etc. are in trapezoidal shapes. Also in this case, the effects described above can be achieved.  FIG. 11  shows a case where the cross sections of the T-shaped projection  10 , the frame-shaped projection  20 , the columnar spacer  204 , etc. are in tongue-like shapes. Also in this case, similar effects can be achieved. 
       Second Embodiment 
       [0059]      FIG. 12  is a schematic plan view showing a liquid crystal display device according to a second embodiment of the present invention.  FIG. 12  differs from  FIG. 3  in the first embodiment in that two frame-shaped projections  20  are formed in parallel on the TFT substrate  100 &#39;s side. By forming two frame-shaped projections  20 , the seal member  150  can be widened more uniformly when the TFT substrate  100  and the counter substrate  200  are bonded to each other. The rest of the configuration is similar to that explained referring to  FIG. 3 . 
         [0060]      FIG. 13  is a perspective view of the part B in  FIG. 12 . Illustration of the seal member is omitted in  FIG. 13  to facilitate the understanding of the drawing.  FIG. 13  differs from  FIG. 4  in the first embodiment in that two frame-shaped projections  20  are formed on the TFT substrate  100 &#39;s side. Further, top apices of the triangles of the two frame-shaped projection  20  are in contact with the top apex of the triangle of the T-shaped projection  10 . In  FIG. 13 , the widths w 1  and w 11  of the T-shaped projection  10  and the width w 2  of each of the two frame-shaped projections  20  are 15 μm similarly to those explained referring to  FIG. 4 . The height h 1  of the T-shaped projection  10  and the height h 2  of the frame-shaped projection  20  are also set similarly to those explained referring to  FIG. 4 . 
         [0061]      FIG. 14  is a plan view of the part B in  FIG. 12 . In  FIG. 14 , the part B is viewed from the counter substrate  200 &#39;s side.  FIG. 14  differs from  FIG. 5  in the first embodiment in that two frame-shaped projections  20  are formed on the TFT substrate  100 &#39;s side. The width of the seal member  150  is approximately 300 μm, whereas the width of each frame-shaped projection  20  is approximately 15 μm, and thus there is no problem in terms of space even if two frame-shaped projections  20  are arranged. The rest of the configuration is similar to that in  FIG. 5 . 
         [0062]      FIG. 15  is a cross-sectional view taken along the line C-C in  FIG. 14 .  FIG. 15  differs from  FIG. 6  in the first embodiment in that two frame-shaped projections  20  are formed in parallel and each of the frame-shaped projections  20  is in contact with the T-shaped projection  10 . With the presence of two frame-shaped projections  20 , the distance between the TFT substrate  100  and the counter substrate  200  in the seal part can be maintained more stably. 
         [0063]      FIG. 16  is a cross-sectional view taken along the line D-D in  FIG. 14 .  FIG. 16  differs from  FIG. 7  in the first embodiment in that two frame-shaped projections  20  are in contact with the T-shaped projection  10 . As shown in  FIG. 16 , the slopes  21  of the triangles of the two frame-shaped projections  20  and the slope  11  of the triangle of the T-shaped projection  10  are bonded to the seal member  150 , and thus the adhesion strength of the seal member  150  can be increased further in comparison with the first embodiment. 
         [0064]    The rest of the configuration and effects of this embodiment are equivalent to those explained in the first embodiment. 
       Third Embodiment 
       [0065]      FIG. 17  is a schematic plan view showing a liquid crystal display device according to a third embodiment of the present invention.  FIG. 17  differs from  FIG. 3  in the first embodiment in that not the T-shaped projection  10  but an H-shaped projection  30  is formed in the peripheral part on the counter substrate  200 &#39;s side. On the TFT substrate  100 &#39;s side, the frame-shaped projection  20  is formed in parallel with each side of the TFT substrate  100  to cross the center of a bridge part of the H-shaped projection  30 . The frame-shaped projection  20  is equivalent to that in the first embodiment. The H-shaped projection  30  is in contact with the frame-shaped projection  20  at the bridge part. 
         [0066]      FIG. 18  is a perspective view of the part C in  FIG. 17 . Illustration of the seal member is omitted in  FIG. 18 . In  FIG. 18 , the cross sections of the H-shaped projection  30  are triangles whose top apices are situated on the lower side. The top apex of the triangle as the cross section of the frame-shaped projection  20  formed on the TFT substrate  100  is in contact with the bridge part of the H-shaped projection  30 . In  FIG. 18 , the width w 31  of a part of the H-shaped projection  30  parallel to the side of the counter substrate  200 , the width w 3  of the bridge part of the H-shaped projection  30 , and the width w 2  of the frame-shaped projection  20  are all approximately 15 μm. The heights of the H-shaped projection  30  and the frame-shaped projection  20  are equivalent to those of the T-shaped projection  10  and the frame-shaped projection  20  in the first embodiment. 
         [0067]      FIG. 19  is a plan view of the part C in  FIG. 17 . In  FIG. 19 , the seal member  150  is arranged in an internal region of the H-shaped projection  30 . The dot line as the center line of the H-shaped projection  30  in  FIG. 19  indicates the triangular cross section&#39;s top apex existing on the back side. The top apex of the frame-shaped projection  20  formed on the TFT substrate  100  is in contact with the top apex of the H-shaped projection  30  approximately at the center of the bridge part of the H-shaped projection  30 . 
         [0068]      FIG. 20  is a cross-sectional view taken along the line E-E in  FIG. 19 . In  FIG. 20 , the bridge part of the H-shaped projection  30  formed on the counter substrate  200  is in contact with the frame-shaped projection  20  formed on the TFT substrate  100 , by which the distance between the TFT substrate  100  and the counter substrate  200  is maintained. The rest of the configuration in  FIG. 20  is equivalent to that in  FIG. 6  of the first embodiment. 
         [0069]      FIG. 21  is a cross-sectional view taken along the line F-F in  FIG. 19 . The dot line of the H-shaped projection  30  in  FIG. 21  indicates that the bridge part of the H-shaped projection  30  lies behind the illustrated part of the seal member  150 . In  FIG. 21 , the top apex of the frame-shaped projection  20  formed on the TFT substrate  100  is in contact with the H-shaped projection  30 . In  FIG. 21 , the area of adhesion of the seal member  150  is increased at slopes  31  of the triangular cross sections of the H-shaped projection  30  formed on the counter substrate  200  and at the slopes  21  of the triangular cross section of the frame-shaped projection  20  formed on the TFT substrate  100 , and thus the adhesivity increases and the reliability of the seal part can be improved. 
         [0070]    While the above first through third embodiments have been described assuming that each of the T-shaped projection, the frame-shaped projection and the H-shaped projection is formed throughout the periphery of the TFT substrate or the counter substrate, the configuration of each projection is not limited to these examples. Similar effects can be achieved even if the projections are formed intermittently along each side of the substrate. It is also possible to form the projections only at positions corresponding to corner parts of the substrates where the control of the seal member width, etc. is relatively difficult. 
         [0071]    Further, the configuration forming the T-shaped projection or the H-shaped projection on the TFT substrate&#39;s side and forming the frame-shaped projection on the counter substrate&#39;s side may also be employed in the present invention as explained referring to  FIGS. 9A and 9B .