Abstract:
A flat-panel display device is provided, that does not allow deformation due to fastening forces of a male screw even despite a gap which is created by a dimensional tolerance or the like between a bezel disposed to a display cell and a housing. Female screws  26  formed in a bezel  22  are deformable in a direction toward an inner surface of the housing  25.  The fastening force of male screws  27,  which penetrates a side wall portion  25   a  of the housing  25  in which the display cell  11  is housed and a side-surface portion  24  of the bezel  22  and which engages with the female screws  26  formed in the bezel  22,  does not cause large deformation.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a flat-panel display device in which a flat-shaped display cell is fixedly housed in a housing by means of a bezel. 
     RELATED ART OF THE INVENTION 
     In general, when assembling a flat-panel display device which comprises a flat-shaped display cell such as a liquid crystal display cell, as shown in FIGS. 16 and 17, a so-called side fixing method is utilized for fastening elements together which requires housing a flat-shaped display cell  11  in a housing not shown with a display surface of the display cell open and to screw-fit a male screw  14  into a bezel  12  through an attaching member  13  which is disposed to a side wall portion of the housing. 
     The bezel  12  is formed by a metallic material into the shape of a picture frame, and as shown in FIG. 17, has a front-surface portion  15  and a side-surface portion  16  which approximately define the letter “L” in cross section. The front-surface portion  15  and the side-surface portion  16  cover the periphery of a front surface and side surfaces of the display cell  11 , whereby the display cell  11  is fixed to the housing. Denoted at  17  is a backlight which is held by a frame  18  which is made of plastic or the like and disposed to a back surface of the display cell  11 . The bezel  12  is fixedly fitted to the frame  18 . 
     In such a flat-panel display device, in the case where there is a gap created between the side-surface portion  16  of the bezel  12  and the attaching member  13  disposed to the housing due to an outside dimensional tolerance of the display cell  11  or an outside dimensional tolerance of the housing, etc., as the male screw  14  is inserted through the attaching member  13  of the housing into engagement with a female screw  19  which is formed in the side-surface portion  16  of the bezel  12  and these elements are fastened together, the fastening force may deform the bezel  12  or the attaching member  13  disposed to the housing and may deviate the center of the housing from the center of the display screen  15 . 
     FIGS. 16 and 17 show a state in which the fastening force pulls one side of the bezel  12  toward the attaching member  13  of the housing, thereby causing bending of the side of the bezel  12 . 
     If the side of the bezel  12  bends in this manner, a display window of the bezel  12  also bends, inviting an inconvenience in that the display window of the housing and the display screen of the display cell  11  are not positionally aligned to each other. Further, with the side of the bezel  12  bent in this manner, downward force acts upon an inner side  15   a  of the front-surface portion  15  of the bezel  12  and strongly pressurizes a surface of the display cell  11 . This may cause pooling due to vibration or disconnection of a tab due to a torsional load during use of the flat-panel display device. 
     On the other hand the fastening force of the male screw  14  deforms the housing in some cases, and since this is distortion created at an unspecified position, positional accuracy between the display cell  11  and the housing decreases, which may induce interference between the display screen of the display cell  11  and a front mask of the housing, etc. 
     A gap created between the bezel  12  fitted at the display cell  11  side and the housing due to a dimensional tolerance or the like leads to a problem in that the fastening force of the male screw  14  which fixes a space between the bezel  12  of the display cell  11  side and the housing creates distortion and various types of inconvenience. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention has been made to solve the problems above. Accordingly, an object of the present invention is to provide a flat-panel display device in which distortion due to the fastening force of a male screw is not created even when a dimensional tolerance or the like creates a gap between a bezel which is fitted with a display cell and a housing. 
     A first aspect of the present invention is directed to a flat-panel display device comprising a display cell which has a flat shape and includes a display screen in a surface, and a bezel for fixing which includes a front-surface portion having an opening portion and shaped like a picture frame and a side-surface portion disposed at sides of said front-surface portion, said bezel covering the periphery of a front surface and side surfaces of said display cell, said flat-panel display device allowing housing of said display cell, covered with said bezel, into a housing with said surface open, 
     wherein a portion of said side-surface portion of said bezel is deformably formed, a female screw is formed in the deformable portion, and said housing is fixedly screwed to said side-surface portion of said bezel which comprises said female screw. 
     According to a second aspect of the present invention, in the flat-panel display device of the first aspect of the present invention, a slit is formed in said side-surface portion so that a portion of said side-surface portion is deformable. 
     According to a third aspect of the present invention, in the flat-panel display device of the first aspect of the present invention, a slit is formed above said female screw so that a portion of said side-surface portion is deformable. 
     According to a fourth aspect of the present invention, in the flat-panel display device of the first aspect of the present invention, slits are formed above and below said female screw so that a portion of said side-surface portion is deformable. 
     According to a fifth aspect of the present invention, in the flat-panel display device of the first aspect of the present invention, slits are formed on the right-hand side and the left-hand side of said female screw so that a portion of said side-surface portion is deformable. 
     According to a sixth aspect of the present invention, in the flat-panel display device of the first to the fifth aspects of the present invention, an angle between said front-surface portion of said bezel and said side-surface portion of said bezel is larger than 90 degrees. 
     A seventh aspect of the present invention is directed to a flat-panel display device, comprising: a display cell which has a flat shape and includes a display screen on the surface; a backlight which is arranged on a back surface of said display cell; a flexible frame which holds said display cell and said backlight as one unit; and a bezel for fixing which includes a front-surface portion having an opening portion and shaped like a picture frame, and a side-surface portion disposed at sides of said front-surface portion, said bezel covering the periphery of a front surface of said display cell and a side-surface portion of said frame, said flat-panel display device allowing housing of said display cell, covered with said bezel, into a housing with said surface open, wherein an opening is formed in side-surface portion of said bezel, a portion of said side-surface portion of said frame is distortionably formed, a female screw is formed in said deformable portion of said side-surface portion of said frame, and a screw is engaged in said female screw from said housing through said opening of side-surface portion of said bezel. 
     According to an eighth aspect of the present invention, in the flat-panel display device of the seventh aspect of the present invention, said side-surface portion of said frame is formed thin so that a portion of said side-surface portion is deformable. 
     According to the present invention, the display cell does not become greatly deformed, which avoids various types of inconveniences induced by distortions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A,  1 B and  1 C show the first preferred embodiment of a flat-panel display device according to the present invention, among which FIG. 1A is a plan view, FIG. 1B is a left-hand side view, and FIG. 1C is a right-hand side view; 
     FIG. 2 is a cross sectional view of FIG. 1 taken along A—A; 
     FIG. 3 is a cross sectional view showing the portion in FIG. 2 as it is attached to a housing; 
     FIG. 4 is a partial view of a slit as it is formed; 
     FIG. 5 is a partial view showing the second preferred embodiment in which a female screw is tongue-like shaped with flexibility; 
     FIG. 6 is a plan view showing the third preferred embodiment; 
     FIG. 7 is a right-hand side view of FIG. 6; 
     FIG. 8 is a plan view showing a relationship with a housing side which is shown in FIG. 6; 
     FIG. 9 is a front cross sectional view of FIG. 8; 
     FIG. 10 is a plan cross sectional view which corresponds to the portion which is shown in FIG. 9; 
     FIG. 11 is a plan view of the portion which is shown in FIG. 8 as it is fastened with a male screw; 
     FIG. 12 is a front cross sectional view of the portion which is shown in FIG. 9 as it is fastened with the male screw; 
     FIG. 13 is a front cross sectional view of the portion which is shown in FIG. 10 as it is fastened with the male screw; 
     FIG. 14 is an explanatory diagram showing the fourth preferred embodiment; 
     FIG. 15 is an explanatory diagram showing the fifth preferred embodiment; 
     FIG. 16 is a plan view for describing a problem with a conventional technique; and 
     FIG. 17 is a cross sectional view of FIG. 16 taken along B—B. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following, the first preferred embodiment of the present invention will be described with reference to FIGS. 1 through 4. 
     Portions which correspond to portions according to the conventional technique shown in FIGS. 16 and 17 will be denoted by identical reference symbols. 
     As shown in FIGS. 1 through 4, a flat-shaped display cell  11 , such as a liquid crystal display cell, and a backlight are housed in a frame, and the frame is housed in a bezel  22  which is formed by a metallic material into the shape of a picture frame. The frame is engaged with the bezel  22 , whereby these two elements are fixed to each other. The two elements may be screwed to each other. 
     The bezel  22 , as shown in FIG. 2, comprises a front-surface portion  23  and a side-surface portion  24  which approximately define the letter “L” in cross section. The front-surface portion  23  and the side-surface portion  24  cover the periphery of a front surface and side surfaces of the display cell  11 , so that the display cell  11  is fixed to a housing  25  which is shown in FIG. 3 directly or indirectly. 
     Female screws  26  are formed in and integrated with the side-surface portion  24  of the bezel  22 . As shown in FIG. 3, male screws  27  are screwed into the female screws  26 , penetrating the side wall portion  25   a  of the housing  25 . 
     A backlight  17  is attached to the back surface of the display cell  11 , and fitted into the frame  18  of plastic or the like together with the display cell  11  as one. 
     With respect to the female screws  26 , for the purpose of enabling deformation of the housing  25  toward an inner surface of the housing  25 , slits  28  are formed in the side-surface portion  24  in the vicinity of the female screws  26  and the areas with the slits  28  are accordingly deformable, as shown in FIGS. 1C,  2 ,  3  and  4 . 
     In FIG. 1A, one side of the bezel  22  on the left-hand side is a reference side  22   a.  Since the position of the reference side  22   a  is fixed, as shown in FIG. 1B, a slit  28  is not formed on the reference side  22   a.    
     During assembly, the display cell  11  mounting the bezel  22  is, as shown in FIG. 3, housed in the housing  25  with a surface of the display cell  11  which serves as a display surface open. Following this, the male screws  27  penetrating the side wall portion  25   a  of the housing  25  are engaged with the female screws  26  which are formed in the side-surface portion  24  of the bezel  22 , thereby fixedly fastening these elements as one unit. 
     If there is a gap between the side-surface portion  24  of the bezel  22  and the inner surface of the housing  25  due to a dimensional tolerance or the like, the fastening force of the male screws  27  pulls the side-surface portion  24  of the bezel  22  toward the side wall portion  25   a  of the housing  25 . 
     To deal with this, slits  28  are formed in the vicinity of the female screws  26  which are formed as integrated portions in the side-surface portion  24  of the bezel  22 . Since the areas where the slits  28  are formed are deformable, only the areas with the slits  28  in the side-surface portion  24  get deformed and pulled toward the side wall portion  25   a  of the housing  25  as shown in FIG.  3 . 
     In short, the other portions including the front-surface portion  23  remain as they originally are, which obviates large bending of one side of the bezel as shown in FIG.  16 . This prevents an inconvenience in that a display window of the housing and the display screen of the display cell  11  are not positionally aligned to each other because of bending of a display window of the bezel. 
     The second preferred embodiment of the present invention will be described with reference to FIG.  5 . 
     The side-surface portion  24  of the bezel  22 , in which the female screws  26  are formed as integrated portions, is shaped as a tongue-like portion, so that the tongue-like portion is flexible. 
     Even in this structure as well, only the female screws  26  bend, on the other hand the other portions including the front-surface portion  23  remain as they are originally are. 
     Hence, it is possible to prevent an inconvenience in that the display window of the housing  25  and the display screen of the display cell  11  are not positionally aligned with each other. 
     In the first and the second preferred embodiments, a downward force may sometimes act upon an inner side of the front-surface portion  23  of the bezel  22  during deformation of the female screws  26 . To deal with this, an angle between the front-surface portion  23  and the side-surface portion  24  of the bezel  22 , which approximately define the letter “L” in cross section, may be set slightly larger than 90 degrees, so that the downward force is reduced. This prevents application of a large load upon the surface portion of the display cell  11 , and hence, disconnection of a tab due to vibration or twisting during use of the flat-panel display device. 
     The third preferred embodiment of the present invention will be described with reference to FIGS. 6 through 13. 
     According to the third preferred embodiment, the frame  18  which integrates the display cell  11  and the backlight  17  with each other comprises a frame side portion  32 . 
     The bezel  22 , which is formed by a metallic material into the shape of a picture frame, is attached to the display cell  11 . The bezel  22  comprises the front-surface portion  23  and the side-surface portion  24  which approximately define the letter “L” in cross section. The front-surface portion  23  and the side-surface portion  24  cover the periphery of a front surface and side surfaces of the display cell  11 . 
     However, unlike in the preferred embodiments described above, the female screws  26  are not formed as integrated portions in the side-surface portion  24  of the bezel  22 , but are formed as separate elements. 
     More specifically, formed in the side-surface portion  24  of the bezel  22  where the female screws  26  are arranged are notched openings  30 . Metallic bar rings  31  which comprise the female screws  26  are, as shown in FIGS. 9 and 10, held by and integrated with thin portions which are formed to have flexibility in the frame side portion  32  which is made of plastic or the like, inside the side-surface portion  24  of the bezel  22 . 
     As shown in these drawings, denoted at  33  is an attaching member which is disposed to a sidewall (not shown) of a housing. 
     During assembly, the display cell  11  mounting the bezel  22  is housed in the housing (not shown) with a surface of the display cell  11  which serves as a display surface open. Following this, the male screws  27  are engaged with the female screws  26  which are formed in the metallic bar rings  31 , penetrating the attaching member  33  which is disposed to the side wall of the housing and through the openings  30  which are formed in the side-surface portion  24  of the bezel  22  in which the male screws  27  are formed, whereby these elements are fixedly fastened as one unit. 
     If there is a gap between the side-surface portion  24  of the bezel  22  and the attaching member  33  which is disposed to the side wall of the housing due to a dimensional tolerance or the like as shown in FIGS. 8 through 10, the metallic bar rings  31  which comprise the female screws  26  are pulled by a fastening force of the male screws  27  toward the attaching member  33  which is disposed to the side wall of the housing. The openings  30  are formed in the side-surface portion  24  of the bezel  22 , and the frame side portion  32  flexibly holds the metallic bar rings  31  which are formed separately and comprise the female screws  26 , so that these portions are deformable. 
     Hence, as shown in FIGS. 11 through 13, only the flexible portions of the frame side portion  32  holding the separate metallic bar rings  31  are deformed because of a pulling force and are pulled through the openings  30  which are formed in the side-surface portion  24  toward the attaching member  33  which is disposed to the side wall of the housing. That is, the other portions including the front-surface portion  23  of the bezel  22  remain as they originally are, which obviates large bending of one side of the bezel as shown in FIG.  16 . This prevents an inconvenience in that a display window of the housing and the display screen of the display cell  11  are not positionally aligned with each other because of bending of the display window of the bezel. 
     The fourth preferred embodiment will be described with reference to FIG.  14 . 
     The fourth preferred embodiment is a modification of the first preferred embodiment. According to the fourth preferred embodiment, the female screws  26  are formed in the side-surface portion  24  of the bezel  22 , and slits  28 ,  28  are formed above and below the female screws  26 . 
     In the fourth preferred embodiment as well, since a portion between the slits  28 ,  28  is flexible, this portion is pulled toward the side wall portion  25   a  of the housing  25 . In other words, the other portions including the front-surface portion  23  remain as they originally are, thereby preventing one side of the bezel from major bending. Hence, it is possible to prevent an inconvenience in that a display window of the housing and the display screen of the display cell  11  are not positionally aligned with each other because of bending of the display window of the bezel. 
     The fifth preferred embodiment will be described with reference to FIG.  15 . 
     The fifth preferred embodiment is a modification of the first preferred embodiment. According to the fifth preferred embodiment, the female screws  26  are formed in the side-surface portion  24  of the bezel  22 , and slits  28 ,  28  are formed on the right-hand side and the left-hand side of the female screws  26 . 
     In the fifth preferred embodiment as well, since a portion between the slits  28 ,  28  is flexible, this portion is pulled toward the side wall portion  25   a  of the housing  25 . In other words, the other portions including the front-surface portion  23  remain as they originally are, thereby preventing one side of the bezel from major bending. Hence, it is possible to prevent an inconvenience in that a display window of the housing and the display screen of the display cell  11  are not positionally aligned with each other because of bending of a display window of the bezel.