Abstract:
Provided is a display apparatus, including: a rectangular display panel including a screen in front; a rectangular sheet located behind the display panel, the sheet having a plurality of holes in a peripheral portion thereof; a light source illuminating the display panel with light from behind the display panel; and a housing accommodating the light source, the housing that has a generally box-like shape having a rectangular opening toward the display panel, and has a plurality of engageable portions arranged along a longitudinal direction in a peripheral portion of the rectangular opening, the plurality of engageable portions capable of engaging respectively with edges of the plurality of holes; wherein the plurality of engageable portions are adjustable in position or orientation so as to contact the edges of the plurality of holes.

Description:
[0001]    This is a continuation of International Application No. PCT/JP2014/081219, with an international filing date of Nov. 26, 2014, the contents of which are hereby incorporated by reference. 
     
    
     BACKGROUND 
     1. Technical Field 
       [0002]    The present invention relates to a display apparatus which includes a display panel including a screen in front, a sheet located behind the display panel and having a plurality of holes in a peripheral portion thereof, a light source illuminating the display panel with light from behind the display panel, and a housing accommodating the light source and having, in a peripheral portion thereof, a plurality of engageable portions capable of engaging respectively with the holes. 
       2. Description of the Related Art 
       [0003]    A liquid crystal display apparatus as a display apparatus has features of being thin and consuming low electric power, and, for improved display quality thereof, has recently been spread as a display apparatus replacing a conventional CRT and also in wide use as an image display apparatus of a television receiver (hereinafter, referred to as a “TV receiver”). Unlike a self-light emitting device, a liquid crystal display apparatus requires a backlight unit as a light source, and displays an image by controlling the light transmittance determined by electro-optical characteristics of a liquid crystal material thereof. 
         [0004]    The backlight unit is available in an edge type (side light type, light guide plate type) and a direct type. 
         [0005]    One type of liquid crystal display apparatus, including an edge-type backlight unit, that is provided for the purpose of being thinner, being more lightweight and having a narrower frame includes a display module and a frame covering the display module. The display module includes a liquid crystal display panel (hereinafter, referred to as a “liquid crystal panel”) and a backlight unit located on a rear surface of the liquid crystal panel. The backlight unit includes a rectangular box-shaped chassis (BL (backlight) chassis), and a light guide plate, an optical sheet and an LED (Light Emitting Diode) substrate accommodated in the BL chassis. The LED substrate includes a lengthy plate and a plurality of LEDs mounted on a flat surface of the lengthy plate. In the case where the backlight unit is of a one-side edge light type, which includes a light source facing one edge of the liquid crystal panel, the LED substrate is located on one of longer side surfaces of the light guide plate, which is rectangular. Light emitted from the LED and incident on the longer side surface of the light guide plate is output from a main surface of the light guide plate and illuminates the rear surface of the liquid crystal panel. 
         [0006]    A direct-type backlight has the following structure. A plurality of LED substrates are provided on a bottom surface of the chassis. A reflector sheet is placed on the bottom surface such that a diffuser lens covering each of LEDs is exposed. A diffuser plate is located at a position slightly away from the diffuser lens toward an opening. An optical sheet is located above the diffuser plate. 
         [0007]    In many display apparatuses of either type, a plurality of engageable portions are provided on a top side portion of an opening edge portion of the chassis, and the optical sheet has holes. The engageable portions are respectively put into engagement with edges of the holes, so that the optical sheet is suspended. 
         [0008]    Japanese Laid-Open Patent Publication No. 2012-113873 (hereinafter “Patent Document 1”) discloses the following invention relating to a backlight device. Engageable portions each having a circular planar shape are provided in a peripheral portion of a chassis, and a light guide film and an optical sheet each having a thickness of 1 mm or less each have elliptical holes slightly larger than the engageable portions. The engageable portions are respectively put into engagement with edges of the holes. With such a structure, the light guide film and the optical sheet are suspended from the chassis without sagging. 
         [0009]    Recently, display apparatuses have been increased in size, and now tolerances are large, and opening edge portions of chasses are easier to be warped. 
         [0010]    Due to such warp, error or the like, the engageable portions may not be aligned in a straight line and a part of the engageable portions may be deviated in position. In the meantime, the holes in the sheet are aligned in a straight line. Therefore, when the sheet is put on the opening edge portion of the chassis in a state where the engaged portion is deviated, there are engageable portions that are not in contact with top edges of the corresponding holes. In this case, the load of the sheet is concentrated on the engageable portions in contact with the edges of the corresponding holes. As a result, a problem that, for example, the sheet is ruptured or wobbled occurs. 
         [0011]    In the backlight unit described in Patent Document 1 also, there may be engageable portions that are not engaged with the holes due to the warp, error or the like of the peripheral portion of the chassis. This causes the problem that the light guide film or the optical sheet may not be suspended from the peripheral portion. 
       SUMMARY 
       [0012]    The present invention made in light of such a situation has an object of providing a display apparatus assembled with high precision, in which engageable portions of a housing are in contact with edges of holes in a sheet so as to put the sheet into engagement with the engageable portions with certainty, and thus the sheet is prevented from being wobbled or ruptured to suppress faults from occurring. 
         [0013]    A display apparatus according to an embodiment of the present invention includes a rectangular display panel including a screen in front; a rectangular sheet located behind the display panel, the sheet having a plurality of holes in a peripheral portion thereof; a light source illuminating the display panel with light from behind the display panel; and a housing accommodating the light source, the housing having a plurality of engageable portions provided in a peripheral portion thereof, the plurality of engageable portions capable of engaging respectively with edges of the plurality of holes. The plurality of engageable portions are adjustable in position or orientation so as to contact the edges of the plurality of holes. 
         [0014]    According to an embodiment of the present invention, in the case where an engageable portion is deviated from the edge of the hole due to the warp, the error or the like of the peripheral portion of the housing, the position or orientation of the engageable portion may be adjusted, so that the engageable portion is put into contact with the edge of the hole with certainty and the sheet is put into engagement with the engageable portions. Since the load of the sheet is not concentrated on a part of the engageable portion, the sheet is not ruptured or wobbled, and faults are suppressed from occurring. Thus, the display apparatus may be assembled with high precision. 
         [0015]    In the display apparatus according to an embodiment of the present invention, the plurality of holes are larger than the plurality of engageable portions. 
         [0016]    According to an embodiment of the present invention, the orientation of the engageable portion may be changed in a state where the engageable portion is present in the hole, so that the engageable portion is put into contact with the edge of the hole, without detaching the engageable portion, namely, with no change in the position of the engageable portion in a height direction of the hole. 
         [0017]    In the display apparatus according to an embodiment of the present invention, the plurality of engageable portions each include a flat plate-like contact portion and a shaft portion vertically provided at one end of a surface of the contact portion; the peripheral portion of the housing has a hole into which the shaft portion is allowed to be fit; and the contact portion is rotatable in a state where the shaft portion is fit into the hole. 
         [0018]    According to an embodiment of the present invention, the contact portion may be rotated in a state where the shaft portion is fit into the hole. Thus, the orientation of the engageable portion is easily changed to put the engageable portion into contact with the edge of the hole. 
         [0019]    In the display apparatus according to an embodiment of the present invention, the engageable portions each include a protruding portion vertically provided at another end of the surface of the contact portion; and the peripheral portion has a plurality of holes into which the protruding portion is allowed to be fit. 
         [0020]    According to an embodiment of the present invention, the protruding portion may be fit into an appropriate hole. Thus, the inclining angle of the engageable portion is easily changed to secure the engageable portion to the peripheral portion with certainty. 
         [0021]    In the display apparatus according to an embodiment of the present invention, the contact portion has a bullet-like planar shape or a polygonal planar shape. 
         [0022]    In the case where the contact portion has a bullet-like planar shape, the engageable portion may be moved to be put into contact with the edge of the hole easily. 
         [0023]    In the case where the contact portion has a polygonal planar shape, the engageable portion contacts the edge of the hole along a “line”, not at a “point”. Therefore, the load of the sheet is dispersed, and the sheet is more suppressed from being ruptured. 
         [0024]    In the display apparatus according to an embodiment of the present invention, the engageable portions each include a parallelepiped contact portion and an elliptical plate-like contact portion overlapping the support portion in a state where a longer-diameter direction of the contact portion matches a longitudinal direction of the support portion; the plurality of engageable portions each include triangular prims-shaped protruding portions provided at both of two ends of the support portion in the longitudinal direction thereof; and the peripheral portion of the housing includes a plurality of fitting portions into which the support portion and the protruding portions are allowed to fit, the plurality of fitting portions being aligned in a width direction of the peripheral portion. 
         [0025]    According to an embodiment of the present invention, the support portion and the protruding portion may be fit into the fitting portion at an appropriate position. Thus, the position of the contact portion is easily changed to put the contact portion into contact with the edge of the hole. 
         [0026]    The display apparatus according to an embodiment of the present invention further includes a rectangular light guide plate or diffuser plate outputting light incident thereon from the light source toward a rear surface of the display panel. The sheet is an optical sheet located between the display panel and the light guide plate or the diffuser plate. 
         [0027]    According to an embodiment of the present invention, the optical sheet having the peripheral portion matched to the peripheral portion of the housing so as to be suspended from the housing is not wobbled or ruptured. Thus, the display apparatus is assembled with high precision. 
         [0028]    According to an embodiment of the present invention, the position or orientation of the plurality of engageable portions is adjustable such that the plurality of engageable portions contact the edges of the holes. Therefore, in the case where an engageable portion is deviated from the edge of the hole, the position or orientation of the engageable portion may be adjusted to put the engageable portion into contact with the edge of the hole with certainty. Thus, the sheet is engaged with the engageable portions. Since the load of the sheet is not concentrated on a part of the plurality of engageable portions, the sheet is not wobbled or ruptured, and faults are suppressed from occurring. Therefore, the display apparatus may be assembled with high precision. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0029]      FIG. 1  is an external isometric view of a TV receiver including a display apparatus (display module) in embodiment 1 according to an embodiment of the present invention, as seen from the front side thereof. 
           [0030]      FIG. 2  is an exploded isometric view of the display module. 
           [0031]      FIG. 3A  is a schematic side view showing an opening edge portion of a BL chassis and an optical sheet. 
           [0032]      FIG. 3B  is a partial enlarged view showing a state where engageable portions are engaged with edges of holes. 
           [0033]      FIG. 4A  is a plan view of an engageable portion. 
           [0034]      FIG. 4B  is a schematic side view showing a state where the engageable portions are engaged with the holes. 
           [0035]      FIG. 5A  shows a side view of the engageable portion and a partial side view of the BL chassis. 
           [0036]      FIG. 5B  shows how the engageable portion is rotated. 
           [0037]      FIG. 6A  is a plan view of an engageable portion in embodiment 2 according to an embodiment of the present invention. 
           [0038]      FIG. 6B  is a schematic side view showing a state where engageable portions are engaged with the holes. 
           [0039]      FIG. 7A  is a side view of an engageable portion. 
           [0040]      FIG. 7B  is a plan view showing a state where the engageable portion is attached to the opening edge portion of the BL chassis. 
           [0041]      FIG. 8A  is a schematic side view of an engageable portion and a hole. 
           [0042]      FIG. 8B  is an isometric view of the engageable portion. 
           [0043]      FIG. 8C  is a schematic side view showing a structure attaching the engageable portion. 
           [0044]      FIG. 9  is a schematic side view showing the optical sheet, a light guide film and the BL chassis. 
       
    
    
     DETAILED DESCRIPTION 
     Embodiment 1 
       [0045]      FIG. 1  is an external isometric view of a TV receiver  1  including a display apparatus (display module)  2  in embodiment 1 according to an embodiment of the present invention, as seen from a front side.  FIG. 2  is an exploded isometric view of the display module  2 .  FIG. 3A  is a schematic side view showing an opening edge portion of a BL chassis  28  and an optical sheet  24 , and  FIG. 3B  is a partial enlarged view thereof showing a state where engageable portions  29  are respectively engaged with edges of holes  241 .  FIG. 4A  is a plan view of an engageable portion  29 .  FIG. 4B  is a schematic side view showing a state where the engageable portions  29  are engaged with the holes  241 .  FIG. 5A  show a side view of the engageable portion  29  and a partial side view of the BL chassis  28 .  FIG. 5B  shows how the engageable portion  29  is rotated. 
         [0046]    The TV receiver  1  is longer in a lateral direction, and includes the display module  2  including a display panel  21  displaying a video image, a tuner  5  receiving broadcast waves from an antenna (not shown), and a decoder  6  decoding encoded broadcast waves. The TV receiver  1  decodes, by the decoder  6 , the broadcast waves received by the tuner  5 , and displays a video image on the display module  2  based on the decoded information. Below the TV receiver  1 , a stand  7  supporting the TV receiver  1  is provided. 
         [0047]    The display module  2  is accommodated in a standing state between a front cabinet  3  and a rear cabinet  4 , both of which are located in a standing state. The front cabinet  3  is a rectangular frame covering a peripheral portion of the display module  2 , and has a rectangular opening at a center thereof. The front cabinet  3  is formed of, for example, a synthetic resin. The rear cabinet  4  has a shape of a rectangular tray opened forward, and is formed of, for example, a synthetic resin. The front cabinet  3  and the rear cabinet  4  may be formed of another material. 
         [0048]    The front cabinet  3  and the rear cabinet  4  are substantially the same as each other in the top side length, the bottom side length, the left side length and the right side length. Peripheral edges of the front cabinet  3  and the rear cabinet  4  face each other. A peripheral portion of the display panel  21  faces an inner edge portion of the front cabinet  3 . 
         [0049]    As shown in  FIG. 2 , the display module  2  includes the display panel  21 , a bezel  22 , a panel chassis  23 , three, for example, optical sheets  24 , a diffuser plate  25 , a reflector sheet  26 , diffuser lenses (each having a built-in LED)  27 , and a BL chassis  28 . 
         [0050]    The BL chassis  28  is formed of, for example, a metal material such as aluminum or the like, and has a generally box-like shape opened toward a light output side (toward the display panel  21 ). 
         [0051]    On a bottom surface of the BL chassis  28 , a plurality of LED substrates (not shown) each including an LED and the diffuser lens  27  covering the LED are provided. The reflective sheet  26  is placed on the LED substrates such that the lenses  27  are exposed. 
         [0052]    The diffuser plate  25  is located with a small gap from the diffuser lenses  27 . On the diffuser plate  25 , the optical sheets  24  are located. 
         [0053]    A backlight unit includes the optical sheets  24 , the diffuser plate  25 , the reflector sheet  26 , the LED substrates, and the BL chassis  28 . The backlight unit used in this embodiment is of a direct type. 
         [0054]    The panel chassis  23  is frame-like, and is located along an outer edge of the BL chassis  28 . The panel chassis  23  and the BL chassis  28  have therebetween, and hold, peripheral portions of the optical sheets  24 . 
         [0055]    The display panel  21  includes a color filter substrate including a plurality of color filters, an active matrix substrate (TFT substrate) located to face the color filter substrate and including a plurality of thin film transistors acting as switching elements, and a liquid crystal layer provided as a display medium layer between the color filter substrate and the active matrix substrate. 
         [0056]    The bezel  22  is formed of, for example, a metal material having high rigidity such as stainless steel or the like, and is a frame having a U-shaped cross-section. The bezel  22  has the peripheral portion of the display panel  21 , the panel chassis  23 , the peripheral portions of the optical sheets  24 , and the opening edge portion of the BL chassis  28  held between two ends of the U-shape. 
         [0057]    As shown in  FIG. 3A , a plurality of engageable portions  29  are located in a longitudinal direction in a top side portion of the opening edge portion of the BL chassis  28 . 
         [0058]    In a top side portion of each of the optical sheets  24 , a plurality of holes  241  are located in correspondence with the engageable portions  29 . The holes  241  are rectangular and larger than the engageable portions  29 . 
         [0059]    As shown in  FIG. 4A , the engageable portions  29  each have a planar shape that may be obtained as a result of vertically cutting an elliptical shape longer in the lateral direction so as to have an area size slightly larger than half of the elliptical shape, namely, each have a shape of a bullet. If the planar shape of the engageable portion  29  is elliptical, when the engageable portion  29  is rotated as described below, a portion of the engageable portion  29  that is opposite to a portion contacting a top edge of the hole  241  contacts a bottom edge of the hole  241 . Therefore, such an opposite portion needs to be cut away. 
         [0060]    As shown in  FIG. 5A , the engageable portion  29  includes a flat plate-like contact portion  291  having a bullet-like planar shape, a shaft portion  292  provided at one end of a rear surface of the contact portion  291 , and a protruding portion  293  provided at another end of the rear surface of the contact portion  291  and having a spherical shape as seen in a plan view. The shaft portion  292  is tapered so as to be thinner at a tip thereof, and is longer than the protruding portion  293 . The contact portion  291  does not need to have a flat surface and may have a curved surface. 
         [0061]    A first fitting hole  281 , into which the shaft portion  292  is allowed to be fit, is provided in the opening edge portion of the BL chassis  28 . A plurality of second fitting holes  282 , into which the protruding portion  293  is allowed to be fit, are provided to form an arc shape in the vicinity of the first fitting hole  281 . 
         [0062]    As shown in  FIG. 5B , the shaft portion  292  of the engageable portion  29  is loosely fit into the first fitting hole  281 , and the protruding portion  293  of the engageable portion  29  is fit into an appropriate second fitting hole  282  among the plurality of second fitting holes  282  to adjust the angle of the engageable portion  29 . In this state, the contact portion  291  is pressed. Thus, the engageable portion  29  is secured to the BL chassis  28 . 
         [0063]    The engageable portions  29  are aligned in a straight lateral line on the opening edge portion of the BL chassis  28 . However, in the case where, as shown in  FIG. 3A , the opening edge portion is warped toward the front side, the engageable portions  29  are not aligned in a straight line. 
         [0064]    The holes  241  are aligned in a straight lateral line, and are larger than the engageable portions  29 . Therefore, in a state where the optical sheets  24  are put on the opening edge portion of the BL chassis  28 , such a situation that the engageable portions  29  are not accommodated in the holes  24  is avoided. However, there is at least one engageable portion  29  that is not in contact with the edge of the hole  241 . In this case, the load of the optical sheets  24  are concentrated on the engageable portions  29  in contact with the top edges of the holes  241 . Therefore, the problem that, for example, the optical sheets  24  are ruptured may occur. 
         [0065]    In this embodiment, the at least one engageable portion  29  not in contact with the edge of the hole  241  is arranged as follows. As shown in  FIG. 3B , the shaft portion  292  of such an engageable portion  29  is floated (put into a loosely fit state) such that the contact portion  291  thereof contacts the edge, and the contact portion  291  is rotated to fit the protruding portion  293  into an appropriate fitting hole  282  among the plurality of fitting holes  282 . Thus, the engageable portion  29  is secured. The engageable portion  29  at the center of  FIG. 3B  is in contact with the top edge of the hole  241  with no need to rotate the contact portion  291 . For the engageable portions  291  on both sides of the engageable portion  29  at the center of  FIG. 3B , the protruding portion  293  of each of such engageable portions  291  is fit into the second fitting hole  282  that is second from the bottom in  FIG. 5B . For the engageable portions  291  at both of two ends of  FIG. 3B , the protruding portion  293  of each of such engageable portions  291  is fit into the second fitting hole  282  that is second from the top in  FIG. 5B . 
         [0066]    As shown in  FIG. 4B , the rotation centers of the engageable portions  29  (centers of the shaft portions  292 ) are not aligned in a straight line. However, the contact portions  291  are rotated, and as a result, all of the engageable portions  29  contact the top edges of the holes  241 . 
         [0067]    All of the engageable portions  29  are engaged with the edges of the holes  241 . Therefore, the weight (load) of the optical sheets  24  is not concentrated on a part of the engageable portions  29  but is distributed to all the engageable portions  29 . Thus, the optical sheets  24  are supported by all the engageable portions  29 . 
         [0068]    As described above, in this embodiment, in the case where an engageable portion  29  is deviated from the edge of the hole  241  due to the warp or error of the peripheral portion of the BL chassis  28 , the inclining angle of the engageable portion  29  may be adjusted, so that the engageable portion  29  is put into contact with the edge of the hole  241  and the optical sheets  24  are put into engagement with the engageable portions  29 . Therefore, the optical sheets  24  are not ruptured or wobbled, and faults are suppressed from occurring. Thus, the display module  2  is assembled with high precision. 
         [0069]    In this embodiment, the engageable portions  29  each include the shaft portion  292  and the protruding portion  293 , whereas the first fitting hole  281  and the second fitting holes  282  are provided in the opening edge portion of the BL chassis  28 . The present invention is not limited to this. Neither the protruding portions  293  nor the second fitting holes  282  may be provided. In this case, the shaft portion  292  of each engageable portion  29  may be loosely inserted into the first hole  281 , and the inclining angle of the contact portion  291  may be determined such that the contact portion  291  contacts the top edge of the hole  241 . Then, the shaft portion  292  may be pressed into the first fitting hole  281  and fit into the first fitting hole  281  with certainty to secure the engageable portion  29 . In this case, the inclining angle is adjustable finely. 
         [0070]    Alternatively, a plurality of the first fitting holes  281  may be aligned in the opening edge portion of the BL chassis  28  in a width direction. With this structure, even in the case where the holes  241  are not sufficiently larger than the engageable portions  29  and the engageable portions  29  are not accommodated in the holes  241  as a result of, for example, the opening edge being warped, the engageable portions  29  may be inserted into the holes  241  and put into contact with the top edges of the holes  241 . In the case where the plurality of second fitting holes  282  are provided in correspondence with the plurality of first fitting holes  281 , the position and the angle of the engageable portions  29  are adjustable finely. 
         [0071]    The engageable portions  29  are not limited to being provided on the top side portion of the opening edge portion of the BL chassis  28 , and the holes  241  are not limited to being provided in the top side portion of the optical sheets  24 . The engageable portions  29  and the holes  241  may be provided on and in, for example, a left edge portion and a right edge portion of the BL chassis  28  and the optical sheets  24 . 
         [0072]    The engageable portions  29  are not limited to being provided on the opening edge portion of the BL chassis  28 , and may be provided on a peripheral area other than the opening edge portion of the BL chassis  28 . 
       Embodiment 2 
       [0073]    A display apparatus in embodiment 2 according to an embodiment of the present invention has substantially the same structure as that of the display apparatus in embodiment 1 except for the shape of the engageable portions  29 . 
         [0074]      FIG. 6A  is a plan view of an engageable portion  29  in embodiment 2 according to an embodiment of the present invention.  FIG. 6B  is a schematic side view showing a state where such engageable portions  29  are respectively engaged with the holes  241 . 
         [0075]    The contact portion  291  of each engageable portion  29  has a pentagonal planar shape. 
         [0076]    The shaft portion  292  like that in embodiment 1 is provided on a rear surface of the contact portion  291 , at a position that is close to the center of the longest side thereof. The protruding portion  293  is provided in the lateral direction from the shaft portion  292 . 
         [0077]    Like in embodiment 1, the first fitting hole (not shown) into which the shaft portion  292  is allowed to be fit, and the second fitting holes (not shown) into which the protruding portion  293  is allowed to be fit, are provided in the opening edge portion of the BL chassis  28 . 
         [0078]    The second fitting holes are each located at a position at which, when the shaft portion  292  is fit into the first fitting hole  291 , the contact portion  291  is rotatable as shown in  FIG. 6B  such that each of sides of the contact portion  291  contacts the top edge of the hole  241 . 
         [0079]    As shown in  FIG. 6B , the contact portion  291  of each engageable portion  29  is in contact with the top edge of the hole  241  along a “line”, not at a “point”. Therefore, the load of the optical sheets  24  is dispersed, and are more difficult to be ruptured. 
       Embodiment 3 
       [0080]    A display apparatus in embodiment 3 according to an embodiment of the present invention has substantially the same structure as that of the display apparatus in embodiment 1 except for the shape of the engageable portions  29 . 
         [0081]      FIG. 7A  is a side view of an engageable portion  29 .  FIG. 7B  is a plan view showing a state where the engageable portion  29  is attached to the opening edge portion of the BL chassis  28 . 
         [0082]    The engageable portion  29  includes a contact portion  291 , a positioning portion  294 , and a shaft portion  292 . The contact portion  291  has a bullet-like planar shape like the contact portion  291  in embodiment 1. The contact portion  291  has a gear groove  295  formed in a bottom surface thereof, and the positioning portion  294  has a gear groove  296  formed in a top surface thereof. The gear groove  295  of the contact portion  291  and the gear groove  296  of the positioning portion  294  are shaped such that the contact portion  291  is rotatable in one direction with respect to the positioning portion  294  but is not rotatable in the opposite direction. 
         [0083]    Like in embodiment 1, the first fitting hole  281 , into which the shaft portion  292  is allowed to be fit, is provided in the opening edge portion of the BL chassis  28 . 
         [0084]    In this embodiment, the shaft portion  292  is fit into the first fitting hole  281  to secure the positioning portion  284  on the opening edge portion of the BL chassis  28 . 
         [0085]    After the position of the positioning portion  294  is determined, the contact portion  291  is fit into the positioning portion  294  and secured. 
         [0086]    In this embodiment, the contact portion  291  may be inclined leftward and also rightward in  FIG. 7B  to put the contact portion  291  into contact with the top edge of the hole  241 . 
       Embodiment 4 
       [0087]    A display apparatus in embodiment 4 according to an embodiment of the present invention has substantially the same structure as that of the display apparatus in embodiment 1 except for the shape of the engageable portions  29 . 
         [0088]      FIG. 8A  is a schematic side view showing an engageable portion  29  and the hole  241 .  FIG. 8B  is an isometric view of the engageable portion  29 .  FIG. 8C  is a schematic side view showing a structure attaching the engageable portion  29 . 
         [0089]    The engageable portion  29  in this embodiment includes a support portion  297  having a parallelepiped shape, and a contact portion  291  having an elliptical plate-like shape and provided to overlap the support portion  297  in a state where a longer-diameter direction of the contact portion  291  matches a longitudinal direction of the support portion  297 . At both of two ends of the support portion  297  in the longitudinal direction, triangular prism-shaped protruding portions  298  are provided. 
         [0090]    As shown in  FIG. 8C , four fitting holes  283  are aligned in an up-down direction in the opening edge portion of the BL chassis  28 . The fitting holes  283  each have a shape of the planar shape of the support portion  297  and the planar shapes of the protruding portions  298  combined. The support portion  297  and the protruding portions  298  are fit into one of the fitting holes  283  at an appropriate position, so that the position of the contact portion  291  protruding from the fitting hole  283  is changed in four steps in the up-down direction. 
         [0091]    Therefore, in the case where the opening edge portion of the BL chassis  28  is, for example, warped and thus the contact portion  291  does not contact the top edge of the hole  241 , the position of the support portion  297  may be changed in the up-down direction to put the contact portion  291  into contact with the top edge of the hole  241  as shown in  FIG. 8A . 
       Embodiment 5 
       [0092]    A display apparatus in embodiment 5 according to an embodiment of the present invention includes an edge-type backlight unit. 
         [0093]      FIG. 9  is a schematic side view showing the optical sheet  24 , a light guide film  30  and the BL chassis  28 . In  FIG. 9 , the display panel  21  is omitted. 
         [0094]    The display apparatus in this embodiment includes a plurality of engageable portions  29  provided on a top edge portion of the BL chassis  28 . The engageable portions  29  have substantially the same structure as that of the engageable portions  29  in embodiment 1. 
         [0095]    The display apparatus in this embodiment includes the light guide film  30 , which is thin. The light guide film  30  and the optical sheet  24  respectively have holes  301  and  241  engageable with the engageable portions  29 . 
         [0096]    In the top edge portion of the BL chassis  28 , the first fitting hole  281  and the second fitting holes  282  are provided. 
         [0097]    In the case where the top edge portion of the BL chassis  28  is warped toward the front side, the engageable portions  29  are not aligned in a straight line. 
         [0098]    The holes  241  and  301  are aligned in a straight lateral line, and are larger than the engageable portions  29 . Therefore, in a state where the light guide film  30  and the optical sheet  24  are put on the top edge portion of the BL chassis  28 , such a situation that the engageable portions  29  are not accommodated in the holes  301  or  241  is avoided. However, there are at least one engageable portion  29  that is not in contact with a top edge of the hole  301  or a top edge of the hole  241 . 
         [0099]    In this case, like in embodiment 1, the protruding portion  293  (not shown) of such an engageable portion  29  is fit into an appropriate second fitting hole  282  among the plurality of second fitting holes  282  in a state where the shaft portion  292  (not shown) of the engageable portion  29  is fit into the first fitting hole  281 , and the contact portion  291  is rotated. Thus, the contact portion  291  is put into contact with the top edges of the hole  301  and the hole  241 . 
         [0100]    Embodiments 1 through 5 disclosed above are examples in all the aspects and should not be construed as limiting the present invention in any way. It is intended that the scope of the present invention is not limited to any of the above-described embodiments and encompasses the equivalents of the claims and all the modifications in the scope of the claims. 
         [0101]    For example, the structures of the engageable portions  29  of the BL chassis  28  and the optical sheets  24  in embodiments 1 through 4 are applicable to a display apparatus including an edge-type backlight unit.