Abstract:
A display device ( 1 ) having a curved display surface ( 2 ) sandwiches a display panel ( 5 ) by means of a pair of curved covers ( 10, 11 ). The display device ( 1 ) has a plurality of engaging sections ( 12 ), which are formed on each of the two side surfaces arranged to face each other with the display panel ( 5 ) therebetween and fix the pair of covers ( 10, 11 ) so that the covers are not removed. An intermediate position (C 1 ) in the curving direction of the covers ( 10, 11 ) and an intermediate position (C 2 ) in the curving direction of the display surface ( 2 ) are shifted from each other. The engaging sections ( 12 ) on each of the two side surfaces are substantially symmetrically arranged with the display panel ( 5 ) therebetween, and the positions where the engaging sections ( 12 ) are arranged include at least the both end sections (E 1,  E 2 ) in the curving direction, and a display surface intermediate section (CB) which includes the intermediate position (C 2 ) of the display surface ( 2 ) in the curving direction.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a display device, and more particularly to a structure of a display device having a curved display surface. 
       BACKGROUND ART 
       [0002]    Conventionally, electronic appliances such as information, television, and amusement appliances incorporate display devices. Representative of such display devices are liquid crystal display devices using liquid crystal. Specifically, liquid crystal display devices are used in mobile telephones, PDAs (personal digital assistants), DVD players, mobile game appliances, notebook PCs (personal computers), PC monitors, television monitors. etc. 
         [0003]    In display devices conventionally in wide use, the display surface is usually flat. On the other hand, recent years have seen proposals of display devices having a curved display surface for, for example, design and other reasons (see, for example, Patent Documents 1 and 2 listed below).  FIG. 10  is a schematic perspective view showing the exterior structure of a conventional liquid crystal display device having a curved display surface. 
         [0004]    As shown in  FIG. 10 , in the conventional liquid crystal display device  100 , a display panel and a backlight disposed behind it are held between a pair of curved covers (consisting of a top cover  101  and a bottom  102 ) so as to form a curved display surface  103 . The top cover  101  has an opening formed in it so as to expose the display surface  103 . 
         [0005]    In the liquid crystal display device  100 , the display panel held between the top and bottom covers  101  and  102  is originally flat, and gets bent when held between the top and bottom covers  101  and  102  so as to produce the curved display surface  103 . Consequently, in the conventional liquid crystal display device  100 , the stress resulting from the display panel being bent causes problems such as displacement of the display panel and uneven display in the liquid crystal display presented on the display surface  103 . 
       List of Citations 
     Patent Literature 
     Patent Document 1: JP-A-2007-333818 
     Patent Document 2: JP-A-2005-134461 
     SUMMARY OF INVENTION 
     Technical Problem 
       [0006]    In view of the problems mentioned above, it is an object of the present invention to provide a display device that has a curved display surface and that is less likely to suffer from uneven display on a display panel. It is another object of the present invention to provide a display device that has a curved display surface and that is less likely to suffer from displacement of a display panel. 
       Solution to Problem 
       [0007]    To achieve the above objects, according to the invention, a display device includes: a display panel kept in a bent state so as to have a curved display surface; a pair of curved covers holding the display panel therebetween; and a plurality of engagement portions formed in each of two side faces disposed opposite each other across the display panel, the engagement portions fixing the covers together so as not to come off. Moreover, in the display device according to the invention, the middle position of the covers in the curve direction is displaced from the middle position of the display surface in the curve direction; the engagement portions provided in one of the two side faces and the engagement portions provided in the other of the two side faces are disposed substantially symmetrically across the display panel; and the positions at which the engagement portions are provided at least include both end parts in the curve direction and a display surface middle part including the middle position of the display surface in the curve direction. 
         [0008]    Here, the “curve direction” is the direction along the bowlike curve along which a curved surface intersects a plane on which lie a plurality of lines normal to the curved surface at different positions. 
         [0009]    With this structure, consideration is given to the fact that the middle position, in the curve direction, of the covers constituting the display device is displaced from the middle position, in the curve direction, of the display surface, and with respect to the middle position of the display surface in the curve direction, the engagement portions are provided. This makes it easy to reduce uneven display occurring on the display screen. In this structure, it is preferable that the center position, in the curve direction, of the engagement portion disposed at the display surface middle part approximately coincide with the middle position of the display surface in the curve direction. 
         [0010]    In the display device structured as described above, it is preferable that the positions at which the engagement portions are provided further include at least one location between one of the end parts and the display surface middle part and at least one location between the other of the end parts and the display surface middle part, and that any engagement portion disposed between the one of the end parts and the display surface middle part and any engagement portion disposed between the other of the end parts and the display surface middle part be disposed substantially symmetrically about the display surface middle part. 
         [0011]    With this structure, it is easy to spread the stress occurring at the engagement portions as a result of a number of engagement portions being provided. Moreover, disposing the engagement portions with respect to the middle position of the display surface in the curve direction makes it easy to spread the stress occurring at the engagement portions in a way that makes uneven display less likely to occur. Moreover, with this structure, as a result of a number of engagement portions being provided, it is possible to keep the display panel in fixed position more securely than is conventionally possible, and this makes dislocation of the display panel less likely to occur. 
         [0012]    In the display device structured as described above, it is further preferable that, of any engagement portion disposed between the one of the end parts and the display surface middle part and any engagement portion disposed between the other of the end parts and the display surface middle part, at least an engagement portion adjacent to the engagement portion disposed at the display surface middle part be disposed between, at one end, the midpoint, in the curve direction, between the engagement portion disposed at the one of the end parts and the engagement portion disposed at the display surface middle part and, at the other end, the midpoint, in the curve direction, between the engagement portion disposed at the other of the end parts and the engagement portion disposed at the display surface middle part. With this structure, a plurality of engagement portions are provided at positions as close as possible to the middle position of the display surface in the curve direction, and this makes it easy to suppress uneven display. 
         [0013]    In the display device structured as described above, the engagement portions may each comprise an engaging claw provided on one of the covers and an engaging hole provided in the other of the covers to engage with the engaging claw. In a modified structure, the engagement portions may each comprise an engaging claw provided on a curved frame member accommodated inside the covers and an engaging hole provided in both of the covers to engage with the engaging claw. 
         [0014]    In the display device structured as described above, the display panel may be a liquid crystal display panel; a backlight may be disposed behind the display panel in the bent state; and the display panel and the backlight may be held between the covers. With this structure, it is possible to give a liquid crystal display device as a representative of display panels a structure that, even with a curved display surface, is less likely to suffer from uneven display or displacement of a display panel. 
       Advantageous Effects of the Invention 
       [0015]    According to the present invention, it is possible to make a display device having a curved display surface less likely to suffer from uneven display on a display panel and less likely to suffer from displacement of a display panel. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0016]    [ FIG. 1 ] is a schematic perspective view of a liquid crystal display device as one embodiment. 
           [0017]    [ FIG. 2 ] is a schematic sectional view along line A-A in  FIG. 1 . 
           [0018]    [ FIG. 3 ] is a schematic sectional view showing the structure of the display panel provided in the liquid crystal display device of the embodiment. 
           [0019]    [ FIG. 4 ] is a schematic plan view illustrating the structure of the liquid crystal display device of the embodiment. 
           [0020]    [ FIG. 5A ] is a diagram illustrating the structure of the top cover provided in the liquid crystal display device of the embodiment, the diagram being a schematic side view of the top cover. 
           [0021]    [ FIG. 5B ] is a diagram illustrating the structure of the bottom cover provided in the liquid crystal display device of the embodiment, the diagram being a schematic side view of the bottom cover. 
           [0022]    [ FIG. 6 ] is a diagram illustrating the structure of the engaging holes formed in the top cover provided in the liquid crystal display device of the embodiment. 
           [0023]    [ FIG. 7 ] is a schematic sectional view showing the relationship between an engaging hole formed in the top cover and an engaging claw formed on the bottom cover in the embodiment. 
           [0024]    [ FIG. 8 ] is a diagrams showing a modified example of the liquid crystal display device of the embodiment. 
           [0025]    [ FIG. 9 ] is a diagrams showing a modified example of the liquid crystal display device of the embodiment. 
           [0026]    [ FIG. 10 ] is a schematic perspective view showing the exterior structure of a conventional liquid crystal display device having a curved display surface. [ FIG. 11 ] is a schematic side view showing the structure of the conventional liquid crystal display device. 
           [0027]    [ FIG. 12 ] is a schematic plan view showing the structure of the conventional liquid crystal display device. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0028]    A description will now be given of a display device embodying the present invention with reference to the accompanying drawings. The following description takes up a liquid crystal display device as an example of a display device. 
         [0029]    First, an outline of the structure of the liquid crystal display device of this embodiment will be described with reference to  FIGS. 1 to 3 .  FIG. 1  is a schematic perspective view of the liquid crystal display device of the embodiment.  FIG. 2  is a schematic sectional view along line A-A in  FIG. 1 .  FIG. 3  is a schematic sectional view showing the structure of the display panel provided in the liquid crystal display device of the embodiment. 
         [0030]    As shown in  FIG. 1 , the liquid crystal display device  1  of the embodiment has a display surface  2  that is curved. Specifically, the display surface  2  is concave. The liquid crystal display device  1  has an FPC (flexible printed circuit)  3  connected to it that is used for input of an external signal. The FPC  3  is, at an end, fitted with a connector  4 . 
         [0031]    As shown in  FIG. 2 , the liquid crystal display device  1  of the embodiment is structured such that a top cover  10  and a bottom cover  11  hold between them a display panel  5  and a backlight  6 . The top and bottom covers  10  and  11  are both substantially rectangular as seen in a plan view, and are both previously curved. The top cover  10  has an opening  7  formed in it so as to form the display panel  2 . The top and bottom covers  10  and  11  are engaged with each other at engaging portions  12 , and are thereby fixed together so that the top cover  10  may not come off the bottom cover  11 . The engaging portions  12  will be described in detail later. 
         [0032]    As shown in  FIG. 3 , the display panel  5  is originally not curved, and gets bent when held between the top and bottom covers  10  and  11  into a curved state as shown in  FIG. 2 . Specifically, the display panel  5  includes a first panel substrate  51 , a second panel substrate  52 , liquid crystal  53 , a first polarizing plate  54 , and a second polarizing plate  55 . The first polarizing plate  54  is stuck on the first panel substrate  51 , and the second polarizing plate  55  is stuck on the second panel substrate  52 . 
         [0033]    The first and second panel substrates  51  and  52  are formed of, for example, glass, and are formed so thin as to be easy to bend. The first and second panel substrates  51  and  52  are disposed such that their respective principal surfaces (largest surfaces) face each other, and are stuck together with a frame-shaped seal  56  such that a predetermined gap is left vertically. The first and second panel substrates  51  and  52  are both substantially rectangular as seen in a plan view, and the second panel substrate  52  is formed larger than the first panel substrate  51 . Thus, part of the second panel substrate  52  lies beyond the edge of the first panel substrate  51 , and in that part of the second panel substrate  52 , an IC chip  57  provided with a circuit for driving the display surface  2  is mounted by, for example, a COG (chip-on-glass) method. 
         [0034]    On the first panel substrate  51 , there are formed, in order of closeness to the liquid crystal  53 , a counter-electrode and a color filter, of which neither is illustrated. On the second panel substrate  52 , there is formed a matrix-like array of switching devices, such as TFTs (thin-film transistors), and pixel electrodes connected to them (none is illustrated). Moreover, for the purpose of driving those switching devices, there are formed a plurality of scanning signal lines and a plurality of data signal lines (none is illustrated) such that the former cross the latter. 
         [0035]    The liquid crystal  53  is sealed in the space surrounded by the first and second panel substrates  51  and  52  and the frame-shaped seal  56 . When a voltage is applied to it, the liquid crystal  53  changes its optical properties (light transmittance). The liquid crystal  53  being sandwiched between the pixel electrodes and the counter-electrode forms the display surface  2  (see  FIG. 1 ), on which liquid crystal display takes place. 
         [0036]    The backlight  6  includes a light guide plate  61 , a reflective sheet  62 , an optical sheet  63 , a holder  64 , and a light-emitting diode (LED)  65 . 
         [0037]    The light guide plate  61  is formed of, for example, polycarbonate resin or the like, and is previously curved. On the bottom surface  61   c  side of the light guide plate  61  is provided the reflective sheet  62 , which reflects part of the light traveling through the light guide plate  61 . Thus, the light that has entered the light guide plate  61  through its edge part  61   a  emanates from the light guide plate  61  through its top surface  61   b  as planar light. 
         [0038]    On the top surface  6  lb side of the light guide plate  61  is provided the optical sheet  63 . Specifically, the optical sheet  63  is composed of three sheets which are, from bottom up, a diffusive sheet, a lower prism sheet, and an upper prism sheet. The optical sheet  63  is provided for the purpose, among others, of extracting the light emanating from the light guide plate  61  efficiently and evenly, and its structure is not limited to the specific one adopted in this embodiment. The reflective sheet  62  and the optical sheet  63  are, in a bent state, accommodated between the top and bottom covers  10  and  11 . 
         [0039]    The holder  64  is a frame member shaped like a picture frame, and is disposed on top the bottom cover  11 . The holder  64  serves to keep in fixed position the light guide plate  61 , the reflective sheet  62 , and the optical sheet  63 . On top of the holder  64 , the display panel  5  is placed, with a peripheral part of the latter adhered to the former. The holder  64  is previously curved. 
         [0040]    The LED  65  comprises a plurality of LEDs disposed near the edge  61   a  of the light guide plate  61 . This allows light to enter the light guide plate  61  through its edge  61   a.  In  FIG. 2 , the LEDs  65  are disposed at predetermined intervals in a row in the direction perpendicular to the plane of the page. The LEDs are mounted on the FPC  3 . 
         [0041]    In outline, the liquid crystal display device  1  of the embodiment is structured as described above. What is prominent about the liquid crystal display device  1  of the embodiment is that it is less likely to suffer from uneven display on the display surface  2  or displacement of the display panel  5 . How this is achieved will now be described. 
         [0042]    First, for easy understanding of the structure of the embodiment, a description will be given of the structure of the conventional liquid crystal display device  100  (see  FIG. 10 ) accompanied by the results of its study by the present applicant, with reference to  FIGS. 11 and 12 .  FIG. 11  is a schematic side view showing the structure of the liquid crystal display device  100 .  FIG. 12  is a schematic plan view showing the structure of the liquid crystal display device  100 .  FIG. 11  omits illustration of an FPC and a connector. 
         [0043]    As shown in  FIG. 11 , in the conventional liquid crystal display device  100 , in a side face  101   a  of the liquid crystal display device  100 , engaging portions  104  for fixing the top and bottom covers  101  and  102  together are provided at three locations. Likewise, though not illustrated, also in the side face  101   b  opposite from the side face  101   a,  engaging portions  104  are provided at three locations symmetrically with those in the side face  101   a.  The engaging portions  104  are each composed of an engaging claw provided on the bottom cover  102  and an engaging hole provided in the top cover  101  so a to engage with the engaging claw. 
         [0044]    In each of the side faces  101   a  and  101   b,  the positions at which the engaging portions  104  are formed are the following three locations: at both end parts, and at a middle part (cover middle part) of the top cover  101  (hence, of the bottom cover  102  as well) in the curve direction. That is, as shown in  FIG. 11 , the distance from the engaging portion  104  disposed at the cover middle part to that disposed at one end part and the distance from the engaging portion  104  disposed at the cover middle part to that disposed at the other end part are both L. 
         [0045]    Here, as shown in  FIG. 12 , in the liquid crystal display device  100 , the middle position C 1  of the top cover  101  (hence, of the bottom cover  102  as well) in the curve direction is displaced from the middle position C 2  of the display surface  103  in the curve direction. This results from the necessity of disposing the IC chip and LEDs for driving the display surface  103 . 
         [0046]    As described earlier, the conventional liquid crystal display device  100  having a curved display surface  103  suffers from uneven display. This uneven display is ascribable to the structure in which the display panel in a bent state is held between the top and bottom covers  101  and  102 . Specifically, the bent display panel produces stress at the engaging portions  104  formed in the top and bottom covers  101  and  102 . 
         [0047]    To eliminate uneven display, accordingly, the stress that occurs at the engaging portions  104  has to be mitigated properly. In this respect, what is of particular note about the conventional structure is that it is not at a position corresponding to the middle position C 2  of the display surface  103  in the curve direction, but at a position corresponding to the middle position C 1  of the top cover  101  in the curve direction, that an engaging portion  104  is provided. That is, the conventional structure pays no attention to the display surface  103  in determining where to provide the engaging portions  104 , with the result that the engaging portions  104  are not formed in a way that suits the purpose of eliminating uneven display. Moreover, while the conventional structure has the engaging portions  104  provided at no more than three locations, namely at the middle and at both ends, it has been found out that, for proper mitigation of the stress occurring at the engaging portions  104 , it preferable to spread the stress as much as possible and to increase the number of engaging portions  104 . Furthermore, also to reduce displacement of the display panel—a problem on its own apart from that of uneven display—, it has been found out that it is preferable to increase the number of engaging portions  104 . 
         [0048]    The liquid crystal display device  1  of the embodiment has been developed out of the above considerations. The description of the liquid crystal display device  1  of the embodiment will now be resumed with reference to  FIGS. 4 to 7 . 
         [0049]      FIG. 4  is a schematic plan view illustrating the structure of the liquid crystal display device  1  of the embodiment.  FIG. 5A  is a diagram illustrating the structure of the top cover  10  provided in the liquid crystal display device  1  of the embodiment, the diagram being a schematic side view of the top cover  10 .  FIG. 5B  is a diagram illustrating the structure of the bottom cover  11  provided in the liquid crystal display device  1  of the embodiment, the diagram being a schematic side view of the bottom cover  11 .  FIG. 6  is a diagram illustrating the structure of the engaging holes  12   a  formed in the top cover  10  provided in the liquid crystal display device of the embodiment.  FIG. 7  is a schematic sectional view showing the relationship between an engaging hole  12   a  formed in the top cover  10  and an engaging claw  12   b  formed on the bottom cover  11  in the embodiment. 
         [0050]    As shown in  FIG. 4 , also in the liquid crystal display device  1  of the embodiment, the middle position C  1  of the top cover  10  (hence, of the bottom cover  11  as well) in the curve direction is displaced from the middle position C 2  of the display surface  2  in the curve direction. Here, however, it is with respect to the middle position C 2  of the display surface  2  that engaging portions  12  are formed. 
         [0051]    The engaging portions  12  are each composed of an engaging hole  12   a  formed in the top cover  10  and an engaging claw  12   b  formed on the bottom cover  11  so as to engage with the engaging hole  12   a.  The engaging holes  12   a  are formed by making through holes in two side faces  10   a  and  10   b  of the top cover  10  (those two side faces are substantially parallel to the plane on which lie the curves extending in the curve direction). The engaging holes  12   a  formed in the two side faces  10   a  and  10   b  are provided at positions substantially symmetric across the display panel  5 . The engaging claws  12   b  are formed by bending parts of two side faces  11   a  and  11   b  of the bottom cover  11  (those two side faces are substantially parallel to the plane on which lie the curves extending in the curve direction). The engaging claws  12   b  formed in the two side faces  11   a  and  11   b  are provided at positions substantially symmetric across the display panel  5 . 
         [0052]    The engaging claws  12   b  engage with the engaging holes  12   a,  and accordingly each engaging pair of them are provided at approximately the same position in the assembled liquid crystal display device  1  in its assembled state. As shown in  FIG. 7 , when the top cover  10  is placed on the bottom cover  11 , the engaging claws  12   b  protruding from the side faces  11   a  and  11   b  of the bottom cover  11  engage with the engaging holes  12   a  in the top cover  10 , and thereby prevents the top cover  10  from coming off the bottom cover  11 . 
         [0053]    Now, with reference mainly to  FIGS. 4 to 6 , the positions at which the engaging holes  12   a  and the engaging claws  12   b  are formed will be described in more detail. Since each engaging pair of the engaging holes  12   a  and the engaging claws  12   b  are formed at approximately the same position as mentioned above, the following description deals only with the engaging holes  12   a.  The positions at which the engaging holes  12   a  and the engaging claws  12   b  are provided are the positions of the engaging portions  12 . 
         [0054]    The engaging holes  12   a  are provided, in each of the two side faces  10   a  and  10   b  along the curves, as follows: one at each end part E 1  and E 2 ; one at a display surface middle part CB in which the middle position C 2  of the display surface  2  in the curve direction falls; two between the display surface middle part CB and the end part E 1 ; two between the display surface middle part CB and the end part E 2 . 
         [0055]    As shown in  FIG. 6 , the engaging hole  12   a  provided at the display surface middle part CB has its center position O in the curve direction approximately coincident with the middle position C 2  of the display surface  2  in the curve direction. It is preferable, though not essential, that the center position O and the middle position C 2  be coincident as in this embodiment. 
         [0056]    The two engaging holes  12   a  provided between the display surface middle part 
         [0057]    CB and the end part El and the two engaging hole  12   a  provided between the display surface middle part CB and the end part E 2  are disposed substantially symmetrically about the engaging hole  12   a  provided at the display surface middle part CB. The reason is that such a structure is preferable for proper elimination of uneven display. This, however, is not meant to limit the scope of application of the present invention. 
         [0058]    Moreover, the two engaging holes  12   a  adjacent to the engaging hole  12   a  disposed at the display surface middle part CB are disposed in the following manner: they are disposed between, at one end, the midpoint m in the curve direction between the engaging hole  12   a  disposed at the end part El and the engaging hole  12   a  disposed at the display surface middle part CB and, at the other end, the midpoint M in the curve direction between the engaging hole  12   a  disposed at the end part E 2  and the engaging hole  12   a  disposed at the display surface middle part CB (see  FIG. 6 ). While the distance (d) from the display surface middle part CB to the midpoint m differs from the distance (D) from the display surface middle part CB to the midpoint M, the two engaging holes  12   a  adjacent to the engaging hole  12   a  disposed at the display surface middle part CB are both disposed inward of (closer to the display surface middle part CB than are) the corresponding midpoints. 
         [0059]    The reason for the above disposition is as follows. The stress occurring at the engaging portions  12  is larger the closer to the middle of the display panel  5 . Thus, providing engaging holes  12   a  as close as possible to the display surface middle part CB makes it possible to spread the stress effectively. From this perspective, in the structure of the embodiment, it is also possible, for example, to dispose the two engaging holes  12   a  disposed between the end part El and the display surface middle part CB both inward of (closer to the display surface middle part CB than is) the midpoint m. In that case, the two engaging holes  12   a  disposed between the end part E 2  and the display surface middle part CB are also disposed inward of (closer to the display surface middle part CB than is) the midpoint M. 
         [0060]    As described above, in the liquid crystal display device  1  of the embodiment, an engaging portion  12  is formed at a location (the display surface middle part CB) corresponding to the middle position C 2  of the display surface  2  in the curve direction. This makes it easy to reduce uneven display occurring on the display surface  2 . Moreover, a plurality of engaging portions  12  are disposed between the end parts E 1  and E 2  and the display surface middle part CB. This makes it easy to spread stress, and helps reduce uneven display properly. Providing a number of engaging holes  12   a  also makes displacement of the display panel  5  less likely. 
         [0061]    It should be understood that the embodiment presented above is in no way meant to limit how the present invention is implemented; many modifications and variations are possible without departing from the objects of the invention. 
         [0062]    For example, although the embodiment deals with a structure in which seven engaging portions  12  are provided in each of the side faces  10   a  and  10   b,  this is not meant to be a limitation; only three of them may instead be provided at the end parts E 1  and E 2  and the display surface middle part CB. Even in that case, the engaging portions  12  are provided with respect to the middle position C 2  of the display surface  2  in the curve direction. This makes it easy to reduce uneven display. To spread the stress occurring at the engaging portions  12 , however, it is preferable, as in the embodiment, to provide further engaging portions  12  between the end parts El and E 2  and the display surface middle part CB. For the purpose of spreading stress, more engaging portions  12  may be provided than there are in the embodiment. 
         [0063]    Although the embodiment deals with a structure in which each engaging portion  12  is composed of an engaging hole  12   a  provided in the top cover  10  and an engaging claw  12   b  provided on the bottom cover  11 , this is not meant to be a limitation. Instead, for example, as shown in  FIG. 8 , an engaging claw  12   b  may be provided on the top cover  10  and an engaging hole  12   a  may be provided in the bottom cover  11 . For another example, as shown in  FIG. 9 , an engaging hole  12   a  may be provided in the top and bottom coves  10  and  11  and an engaging claw  12   b  may be provided on the holder  64  accommodated inside the top and bottom coves  10  and  11 . For yet another example, in a structure where the holder extends out of the bottom cover, an engaging hole may be formed in the top cover and an engaging claw may be provided on the holder.  FIGS. 8 and 9  are diagrams each showing a modified example of the liquid crystal display device  1  of the embodiment. 
         [0064]    Although the foregoing discusses a liquid crystal display device having a liquid crystal display panel as a display panel, the application of the present invention is not limited to liquid crystal display devices. Specifically, the invention is naturally applicable to, for example, display devices having a display panel using an electrooptic material other than liquid crystal as an optical switching material. Although the foregoing discusses a case where the display surface is concave, the present invention is applicable also in cases where the display surface is convex. 
       INDUSTRIAL APPLICABILITY 
       [0065]    The present invention is applicable to display devices having a curved display surface, and is suitably applicable particularly to liquid crystal display devices. 
       LIST OF REFERENCE SIGNS 
       [0066]      1  Liquid crystal display device 
         [0067]      2  Display surface 
         [0068]      5  Display panel 
         [0069]      6  Backlight 
         [0070]      10  Top cover 
         [0071]      10   a,    10   b  Side face of top cover 
         [0072]      11  Bottom cover 
         [0073]      11   a ,  11   b  Side face of bottom cover 
         [0074]      12  Engaging portion 
         [0075]      12   a  Engaging hole 
         [0076]      12   b  Engaging claw 
         [0077]      51  First panel substrate 
         [0078]      52  Second panel substrate 
         [0079]      53  Liquid crystal 
         [0080]      64  Holder (frame member) 
         [0081]    C 1  Middle of cover in curve direction 
         [0082]    C 2  Middle of display surface in curve direction 
         [0083]    CB Display surface middle part 
         [0084]    E 1 , E 2  End part 
         [0085]    m, M Midpoint 
         [0086]    O Center