Abstract:
Provided is a display device with a narrowed frame capable of preventing pooling. A display device includes a display unit ( 69 ) including a liquid-crystal display panel ( 59 ), an internal frame (FM) covered with the liquid-crystal display panel ( 59 ), and a rear case (CS 1 ) accommodating the internal frame (FM). Ribs (RB) of the rear case (CS 1 ) support a touch panel ( 79 ) while separating the touch panel ( 79 ) from the internal frame (FM).

Description:
TECHNICAL FIELD 
     The present invention is related to a display device incorporating a touch panel. 
     BACKGROUND ART 
     These days, many liquid crystal display devices incorporate a touch panel. For example, the touch panel, which is operable intuitively, is often adopted in liquid crystal display devices incorporated in devices such as a navigation system provided in vehicles. 
     However, liquid crystal display devices (display devices) incorporating a touch panel suffer problems attributable to touch input. The problems will be described by using a liquid crystal display device  189  shown in  FIGS. 5 to 9  (here,  FIGS. 6 and 7  are sectional views taken along lines a-a′ and b-b′, respectively, in  FIG. 5 , and viewed from a direction indicated by arrows in  FIG. 5 ; any member indicated without hatching is shown in side view). 
     As shown in  FIGS. 5 to 7 , in the liquid crystal display device  189 , a liquid crystal display panel (a display panel)  159  and a backlight unit  149  are accommodated in a box-shaped rear case cs 1 , and a picture-frame shaped front case cs 2  is placed over the liquid crystal display panel  159  accommodated in the rear case cs 1 . With the two cases cs 1  and cs 2  fixed to each other, the liquid crystal display panel  159  and the backlight unit  149  are supported between the two cases (herein, the liquid crystal display panel  159 , the backlight unit  149 , and the two cases cs 1  and cs 2  holding the liquid crystal display panel  159  and the backlight unit  149  therebetween will together be referred to as a display unit  169 ). Further, a touch panel  179  is placed over the front case cs 2  via a picture-frame shaped cushion sheet  171 . 
     With this arrangement, various problems arise when touch input is performed on the touch panel  179  and thus pressure is applied thereto as shown in  FIGS. 8 and 9  which are enlarged sectional views corresponding to  FIGS. 6 and 7 , respectively. Such problems are caused by transmission of the pressure applied to the touch panel  179 , as shown in  FIG. 8 , to the cushion sheet  171 , then to the front case cs 2 , and further to an internal frame (a frame) fm which serves as the framework of the backlight unit  149 . 
     If pressure is applied to the internal frame fm in this way, the pressure causes partial distortion of the internal frame fm. This results in a phenomenon (pooling phenomenon) in which a display surface of the liquid crystal display panel  159  attached to a support surface fmu of the internal frame fm via a double-stick tape (unillustrated) is adversely affected by the distortion of the internal frame fm and becomes wavy (here, the position of the liquid crystal display panel  159  is regulated by a positioning member fmt which protrudes from the support surface fmu; see  FIG. 6 ). If the pooling phenomenon occurs in this way, it degrades the quality of images displayed on the liquid crystal display device  189 . 
     Further, as shown in  FIG. 9 , the pressure applied to the touch panel  179  may be transmitted excessively to the front case cs 2  via the cushion sheet  171 . 
     Such excessive application of pressure to the front case cs 2  makes part of the inner circumference of the picture-frame shaped front case cs 2  come into contact with the liquid crystal display panel  159 , and this includes the pooling phenomenon in the liquid crystal display panel  159 . 
     A possible solution to the pooling phenomenon described above is, as shown in  FIG. 10 , to increase the rigidity of the front case cs 2  by, for example, increasing a thickness t of the front case cs 2  or increasing a width w of one side of the frame. This makes the front case cs 2  less likely to warp even when excessive pressure is applied to the front case cs 2 . 
     Another possible solution is, as disclosed in Patent Literature 1, to adopt a comparatively large-sized case cs to support the touch panel  179  and to couple the touch panel  179  to the liquid crystal display panel  159  via an adhesive layer  191 . With this structure, the case cs is prevented from warping, and furthermore, since the liquid crystal display panel  159  is out of contact with the case cs, the pooling phenomenon attributable to the case cs is less likely to occur in the liquid crystal display panel  159 . 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: JP-A-H10-73805 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     However, with the liquid crystal display device  189  as shown in  FIGS. 10 and 11 , side portions of the case cs located along the periphery of the liquid crystal display panel  159  tend to be wide, which prevents achievement of so-called narrowing of frame (see w in  FIG. 10 ). 
     Also, in  FIG. 11 , the touch surface of the touch panel  179  and the display surface of the liquid crystal display panel  159  are connected to each other via the adhesive layer  191 . Thus, if the touch panel  179  is made to warp by touch input performed thereon, the display surface of the liquid crystal display panel  159  is also likely to warp by being affected by the warp of the touch panel  179 . Thus, the pooling phenomenon is not completely eliminated in the liquid crystal display device  189 . 
     The present invention has been made to solve the above problems. An object of the present invention is to provide a display device where elimination of the pooling phenomenon and the narrowing of frame are both achieved simultaneously. 
     Solution to Problem 
     According to the present invention, a display device includes a touch panel and a display unit that responds to an input operation performed via the touch panel. Here, the display unit includes a display panel, a frame covered with the display panel, and a first case that holds the frame, and the first case includes a support portion that supports the touch panel, keeping the touch panel away from the frame. 
     With this arrangement, when touch input is performed on the touch panel, pressures applied via the touch panel is applied to the first case, not to the frame. Thus, the frame does not sag or warp, and thus the display panel which covers the frame does not receive pressure from the frame. As a result, no inconvenience such as wavy display surface of the display panel (a pooling phenomenon) arises attributable to the frame. 
     Moreover, since the frame does not receive pressure, it does not have to be excessively rigid, and if the frame is picture-frame shaped, each side of the picture-frame shape can be formed narrow, and further, thin. Thus, narrowing of frame is achieved and the pooling phenomenon is eliminated in such a display device. 
     Preferably, for the purpose of avoiding contact between the support portion of the first case and the frame, the frame includes a frame opening portion, and the support portion supports the touch panel through the frame opening portion. 
     Still preferably, a second case is disposed between the touch panel and the display panel, and the support portion of the first case supports the touch panel, keeping the touch panel away from the second case. 
     With this arrangement, when touch input is performed on the touch panel, pressure applied to the touch panel is transmitted to the first case via the support portion, not to the second case. Consequently, the pressure does not cause the second case to sag or warp, and thus no pressure is applied to the display panel from the second case placed over the display panel. As a result, the display device is free from inconveniences such as the display surface of the display panel becoming wavy. 
     Moreover, since the second case does not receive pressure, it does not have to be excessively rigid, and if the second case is picture-frame shaped, each side of the picture-frame shape can be formed narrow, and further, thin. Thus, narrowing of frame is achieved and the pooling phenomenon is eliminated in such a display device. 
     Preferably, for the purpose of avoiding contact between the support portion of the first case and the second case, the second case includes a case opening portion, and the support portion supports the touch panel through the case opening portion. 
     Advantageous Effects of Invention 
     According to the present invention, pressure applied via the touch panel is not transmitted to the frame which is covered with the display panel and thus faces the display panel. Thus, the frame does not suffer problems such as deformation, and does not come into contact with the display panel. Consequently, no problem (for example, the pooling phenomenon) occurs on the display surface of the display panel. Moreover, since no pressure is applied to the frame, the frame can be made thin and narrow, and thus the liquid crystal display device can be thin and compact. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  A sectional view taken along line A-A′ and viewed from the direction indicated by arrows in  FIGS. 3 and 4 ; 
         FIG. 2  A sectional view taken along line B-B′ and viewed from the direction indicated by arrows in  FIGS. 3 and 4 ; 
         FIG. 3  An exploded plan view showing part of members included in a liquid crystal display device; 
         FIG. 4  An exploded perspective view showing a liquid crystal display device; 
         FIG. 5  An exploded perspective view showing a conventional liquid crystal display device; 
         FIG. 6  A sectional view taken along line a-a′ and viewed from the direction indicated by arrows in  FIG. 5 ; 
         FIG. 7  A sectional view taken along line b-b′ and viewed from the direction indicated by arrows in  FIG. 5 ; 
         FIG. 8  An enlarged sectional view showing a problem that arises in a conventional liquid crystal display device; 
         FIG. 9  An enlarged sectional view showing a problem arising in a conventional liquid crystal display device; 
         FIG. 10  A sectional view showing a pooling-proofed liquid crystal display device to which an anti-pooling measures are applied; and 
         FIG. 11  A sectional view showing a conventional liquid crystal display device. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiment 1 
     Hereinafter, an embodiment of the present invention will be described based on the drawings. Hatching, reference signs for members and the like may sometimes be omitted in a drawing for ease of description, and in such a case, a different drawing is to be referred to. Reversely, views other than sectional views may be shown with hatching for the sake of convenience. A black dot in a drawing indicates a direction perpendicular to the sheet on which the drawing is drawn. 
     The following description will deal with a liquid crystal display device as an example of a display device, but this is not meant to limit the present invention. For example, the display device may be an organic EL (electro-luminescence) display or a plasma display. 
       FIG. 4  is an exploded perspective view showing a liquid crystal display device  89  in an exploded manner.  FIG. 3  is an exploded plan view showing part of members included in the liquid crystal display device  89  (for the sake of convenience, most part of a later-described backlight unit  49  is omitted). For the sake of convenience,  FIG. 3  shows the members, which are stacked, in such a manner that they are displaced from each other in a direction indicated by the solid arrow (note that the closer to the tip of the arrow a member is illustrate, the upper in the stack of the members the member is located). 
       FIG. 1  is a sectional view taken along line A-A′ and viewed from a direction indicated by arrows in  FIGS. 3 and 4  (here, any member without hatching is a member visible sideways).  FIG. 2  is sectional view taken along line B-B′ and viewed from a direction indicated by arrows in  FIGS. 3 and 4 . 
     As is clear from each of these figures, the liquid crystal display device  89  includes a display unit  69  and a touch panel  79  that covers the display unit  69 . 
     First, the display unit  69  will be described. The display unit  69  includes a liquid crystal display panel  59 , the backlight unit  49 , and a case CS (a rear case CS 1  and a front case CS 2 ) that holds the liquid crystal display panel  59  and the backlight unit  49  therein. 
     As shown in  FIGS. 1 and 2 , for example, the liquid crystal display panel (a display panel)  59  includes an active matrix substrate  51 , a counter substrate  52 , polarization films  53  and  54 , and an FPC (flexible printed circuits) board  55  (see  FIG. 4 ) for the panel. 
     Specifically, the liquid crystal display panel  59  is formed by bonding the active matrix substrate  51  including switching devices such as TFTs (thin film transistors) and the counter substrate  52  facing the active matrix substrate  51  to each other with a seal member (not shown). And liquid crystal (not shown) is sealed in a space between the substrates  51  and  52 . 
     The polarization film  53  is attached to the active matrix substrate  51  while the polarization film  54  is attached to the counter substrate  52 , such that the polarization films  53  and  54  hold the active matrix substrate  51  and the counter substrate  52  therebetween. 
     The FPC board (a first circuit board)  55  for the liquid crystal display panel  59  is a flexible circuit board including a current supply conductor (not shown). The FPC board  55  for the panel is electrically and physically connected to the active matrix substrate  51 . 
     The back light unit  49  supplies light to the liquid crystal display panel  59 , which does not emit light by itself. Thus, the liquid crystal display panel  59  exerts its display function by receiving light (backlight light) from the backlight unit  49 . Consequently, the display quality of the liquid crystal display panel  59  will be improved by uniform irradiation of the entire surface of the liquid crystal display panel  59  with the light from the backlight unit  49 . 
     As shown in  FIG. 4 , for example, the backlight unit  49  includes an LED module MJ, a light guide plate  43 , a reflecting sheet  44 , an optical-sheet group  45  (a diffusion sheet  45 A, lens sheets  45 B and  45 C), and an internal frame FM. 
     The LED module MJ is a light emitting module and includes an LED (light emitting diode)  41  and a mount substrate  42  on which the LED  41  is mounted. 
     The LED  41  is mounted on an electrode (unillustrated) formed on a mounting surface of the mount substrate  42 , and thereby receives electric current and emits light. To acquire sufficient amount of light, it is preferable that a plurality of LEDs (point light sources)  41  are mounted as the LED  41  on the mount substrate  42 . In the drawings, however, for the sake of convenience, merely part of the LEDs  41  are illustrated (hereinafter, the direction in which the LEDs  41  are aligned will be referred to as an alignment direction P). 
     The light guide plate  43  is a plate-like member that has side surfaces  43 S and a top and bottom surfaces  43 U and  43 B that are positioned so as to hold the side surfaces  43 S therebetween. One of the side surfaces  43 S is a light receiving surface which faces light emitting surfaces of the LEDs  41  and thereby receive light from the LEDs  41 . The received light is repeatedly reflected inside the light guide plate  43 , and outputted to the outside through the top surface  43 U as planar light. 
     The reflecting sheet  44  is located to be covered with the light guide plate  43 . One surface of the reflecting sheet  44  that faces the bottom surface  43 B of the light guide plate  43  functions as a reflecting surface  44 U. Thus, the reflecting surface  44 U reflects light, such as light from the LEDs  41  and light transmitted through the light guide plate  43 , back to the light guide plate  43  (specifically, through the bottom surface  43 B of the light guide plate  43  to the light guide plate  43 ) without allowing leakage of light. 
     The optical-sheet group  45  includes the single diffusion sheet  45 A and the two lens sheets  45 B and  45 C. Specifically, it can be said that a plurality of sheets, namely, the diffusion sheet  45 A, the lens sheet  45 B, and the lens sheet  45 C that are stacked in this order form the optical-sheet group  45 . 
     The diffusion sheet  45 A is located to cover the top surface  43 U of the light guide plate  43 , and the diffusion sheet  45 A diffuses the planar light from the light guide plate  43  to thereby deliver light all over the liquid crystal display panel  59 . 
     The lens sheets  45 B and  45 C are each an optical sheet that has a surface including, for example, a prism structure and deflects the radiation property of light, and so positioned as to cover the diffusion sheet  45 A (specifically, the lens sheet  45 B covers the diffusion sheet  45 A, and the lens sheet  45 B is covered with the lens sheet  45 C). With this arrangement, the lens sheets  45 B and  45 C collect light coming from the diffusion sheet  45 A to thereby achieve improved brightness. Incidentally, a direction in which light collected by the lens sheet  45 B is dispersed and a direction in which light collected by the lens sheet  45 C is dispersed cross each other. 
     The internal frame (a frame) FM is a picture-frame shaped member, and holds the above-described various members by surrounding them (the point is that the internal frame FM serves as the framework of the backlight unit  49 ). Specifically, the internal frame FM holds the reflecting sheet  44 , the light guide plate  43 , and the optical-sheet group  45  stacked in this order (incidentally, the direction in which these members are stacked will be referred to as a stacking direction Q, and a direction that crosses (for example, at right angles to each other) the alignment direction P and the stacking direction Q will be referred to as a crossing direction R). 
     Further, the internal frame FM supports the liquid crystal display panel  59  by part of a front surface thereof. Specifically, a support surface FMu, which is part of the front surface of the internal frame FM that faces the liquid crystal display panel  59 , supports the periphery of the liquid crystal display panel  59  (it is desirable that an unillustrated double-stick tape is disposed between the liquid crystal display panel  59  and the support surface FMu). 
     Protrusions FMt are formed on the support surface FMu of the internal frame FM, and the position of the liquid crystal display panel  59  is determined with respect to the internal frame FM by sides of the protrusions FMt coming into contact with sides of the liquid crystal display panel  59  (that is, the protrusions FMt function as positioning members for positioning the liquid crystal display panel  59 ). 
     In the above-described backlight unit  49 , light from the LEDs  41  is outputted by the light guide plate  43  as planar light, and the planar light travels through the optical-sheet group  45  to be thereby outputted as backlight light having improved emission brightness, and reaches the liquid crystal display panel  59 . 
     Next, the case CS (CS 1  and CS 2 ) will be described. The case CS is divided into two parts, namely, a rear case (a first case) CS 1  which is covered with the backlight unit  49  and a front case (a second case) CS 2  which covers the liquid crystal display panel  59 , the liquid crystal display panel  59  and the backlight unit  49  being stacked together. 
     The rear case CS 1  is a box shaped member, and accommodates various members such as the reflecting sheet  44 , the light guide plate  43 , and the optical-sheet group  45  by holding the internal frame FM (that is, the rear case CS 1  accommodate the backlight unit  49 ). 
     The front case CS 2  is a picture-frame shaped member; it is placed over the liquid crystal display panel  59  which is disposed on the internal frame FM of the backlight unit  49 , such that the display screen of the liquid crystal display panel  59  is exposed (in short, the front case CS 2  covers the periphery of the liquid crystal display panel  59 , leaving the other part of the liquid crystal display panel  59  exposed). 
     The front case CS 2  and the rear case CS 1  are fixed to each other, and thereby, the case CS (CS 1  and CS 2 ) holds the liquid crystal display panel  59  and the backlight unit  49  therein. Inside the case CS (CS 1  and CS 2 ), the backlight unit  49  is fixed to the rear case CS 1  via the internal frame FM. 
     The display unit  69  having the case CS (CS 1  and CS 2 ) as its outer package supports the touch panel  79  via the cushion sheet  71  which is picture-frame shaped like the front case CS 2 . Specifically, a support surface CS 2   u , which is part of a front surface of the front case CS 2  and faces the touch panel  79 , supports the periphery of the touch panel  79  via the cushion sheet  71 . 
     The touch panel  79 , when it is pressed down (for touch input) with, for example, a finger tip of a pen, generates a signal according to which position therein is pressed down. The signal is generated according to variation in amount of charge displacement on the touch panel surface. 
     The touch panel  79  sends the generated signal to a touch position detecting circuit (not shown), and the touch position detecting circuit generates positional data of the touch panel surface from the received signal, and sends the positional data to a control portion (not shown) that performs overall control of the liquid crystal display device  89 . The control portion recognizes what is instructed by the touch input based on the positional data, and, for example, switches the display screen of the liquid crystal display panel  59  (that is, the display unit  69  including the liquid crystal display panel  59  and the backlight unit  49  responds to the input operation performed on the touch panel  79 ). 
     If the liquid crystal display device  89  is incorporated in an apparatus such as a navigation system, the control portion controls navigation contents, or controls a music playing-back device included in the navigation system (here, the control portion may be located outside the liquid crystal display device  89  but inside the navigation system). 
     Now, a description will be given of a member that receives pressure generated by touch input performed on the touch panel  79  (that is, a member that supports the touch panel  79 ). The member is a rib (a support portion) RB formed on the rear case CS 1 . The rib RB is formed on a side wall CS 1   s  of the box-shaped rear case CS 1 . 
     For example, as shown in  FIG. 4 , the rib RB is formed on each of two side walls CS 1   s  (each of opposing side walls CS 1   s ) extending along the short side direction of the rear case CS 1 . In  FIG. 4 , two ribs RB are formed on one of the side walls CS and two ribs RB are formed on the other one of the side walls CS 1   s ; however, there is no particular limitation to the number and the positions of the ribs RB. 
     In each of the side walls CS 1   s , these ribs RB protrude from an edge of the side wall CS 1   s  along a direction (same direction as the stacking direction Q) in which the side wall CS 1   s  rises. In particular, the ribs RB protrude higher than an edge of the side wall CS 1   s  that faces the liquid crystal display panel  59 . 
     Thus, if the internal frame FM of the backlight unit  49  is placed over the rear case CS 1  as shown in  FIGS. 1 and 2 , the ribs RB may come into contact with the internal frame FM. However, the internal frame FM includes frame apertures (frame opening portions) FMo for placing the ribs RB therethrough. Thus, as shown in  FIG. 1 , the ribs RB protrude to the liquid crystal display panel  59  side through the frame apertures FMo, to thereby avoid contact with the internal frame FM. 
     Furthermore, the ribs RB has a length that is greater in dimension than a thickness of the liquid crystal display panel  59 . Thus, if the front case CS 2  is placed over the liquid crystal display panel  59  as shown in  FIGS. 1 and 2 , the ribs RB may come into contact with the front case CS 2 . However, the front case CS 2  includes case apertures (case opening portions) CS 2   o  for placing the ribs RB therethrough. Thus, the ribs RB protrude to the touch panel  79  side through the case apertures, to thereby avoid contact with the front case CS 2 . 
     As a result, tips of the ribs RB are closer to the touch panel  79  than the support surface CS 2   u  of the front case CS 2  is. Thus, the ribs RB support the touch panel  79  via the cushion sheet  71 . That is, in a case where, in the liquid crystal display device  89  incorporating the touch panel  79  and the display unit  69 , the display unit  69  includes the rear case CS 1  that holds the liquid crystal display panel  59 , the internal frame FM that is covered with the liquid crystal display panel  59 , and the rear case CS 1  that holds the internal frame FM, the ribs RB of the rear case CS 1  support the touch panel  79 , keeping the touch panel  79  away from the internal frame FM. 
     With this arrangement, pressure applied via the touch panel  79  when touch input is performed thereon is transmitted to the rear case CS 1  via the ribs RB, not to the internal frame FM. Thus, the internal frame, which does not receive the pressure, does not sag or warp (that is, the internal frame is not deformed). Hence, no pressure is transmitted from the internal frame FM to the liquid crystal display panel  59  that covers the internal frame FM. This eliminates inconveniences such as a wavy display surface of the liquid crystal display panel  59  (the pooling phenomenon) (note that, since the pooling phenomenon does not occur, the image quality of the liquid crystal display device  89  is not degraded). 
     Moreover, since no pressure is applied to the internal frame FM, there is no need of excessively increasing the rigidity of the picture-frame shaped internal frame FM by, for example, increasing the width and thickness of the sides thereof. This helps make the internal frame FM thin and narrow-framed (that is, helps reduce a width of the support surface FMu forming side portions of the internal frame FM), and thus helps make the liquid crystal display device  89  thin and compact. 
     As shown in  FIG. 1 , the ribs RB are out of contact with the internal frame FM by being placed through the frame apertures FMo to protrude to the liquid crystal display panel  59  side than the support surface FMu of the internal frame FM. 
     With this arrangement, since the ribs RB are fitted into the frame apertures FMo, even if excessive vibration is applied to the liquid crystal display device  89 , the internal frame FM does not come off from the rear case CS 1 , and thus the liquid crystal display panel  59  does not come off from the rear case CS 1 , either (here, the internal frame FM and the liquid crystal display panel  59  are coupled to each other by an unillustrated double-stick tape). Thus, in the display unit  69 , and thus in the liquid crystal display device  89 , the liquid crystal display panel  59  is stably positioned. 
     Moreover, in the liquid crystal display device  89 , the picture-frame shaped front case CS 2  is fixed to the rear case CS 1  that accommodates the backlight unit  49  therein, and is also placed over the liquid crystal display panel  59  supported by the internal frame FM of the backlight unit  49 . That is, the front case CS 2  is disposed between the touch panel  79  and the liquid crystal display panel  59 . Thus, the ribs RB of the rear case CS 1  supports the touch panel  79 , keeping the touch panel  79  away from the front case CS 2 . 
     With this arrangement, pressure applied via the touch panel  79  when touch input is performed thereon is transmitted to the rear case CS 1  via the ribs RB, not to the front case CS 2 . Thus, the front case CS 2 , which does not receive the pressure, does not sag or warp (that is, the front case CS 2  is not deformed). Hence, no pressure is transmitted from the front case CS 2  to the liquid crystal display panel  59  that is covered with the front case CS 2  (for example, the front case CS 2  is not so deformed as to come into contact with the liquid crystal display panel  59 ). As a result, problems such as a wavy display surface of the liquid crystal display panel  59  (the pooling phenomenon) do not arise. 
     Moreover, since no pressure is applied to the front case CS 2 , there is no need of excessively increasing the rigidity of the picture-frame shaped front case CS 2  by, for example, increasing the width and thickness of the sides thereof. This helps make the front case CS 2  thin and narrow-framed (that is, helps reduce a width of the support surface CS 2   u  that forms side portions of the front case CS 2 ), and thus helps make the liquid crystal display device  89  thin and compact. 
     As shown in  FIG. 1 , the ribs RB are out of contact with the internal frame FM by being placed through the case apertures CS 2   o  to protrude to the liquid crystal display panel  59  side than the support surface CS 2   u  of the front case CS 2 . 
     With this arrangement, the ribs RB are fitted into the case apertures CS 2   o , and thus, even if excessive vibration is applied to the liquid crystal display device  89 , the front case CS 2  is securely prevented from coming off from the rear case CS 1  (that is, the front case CS 2  is prevented from coming off from the rear case CS 1  by increased number of means). This contributes to achieving a stronger outer package of the display unit  69  (stronger coupling between the cases CS 1  and CS 2 ). 
     Other Embodiments 
     It should be understood that the embodiments specifically described above are not meant to limit the present invention, and that many variations and modifications can be made within the spirit of the present invention. 
     For example, according to the above descriptions, as shown in  FIG. 4 , the ribs RB are formed on the two short ones of the side walls CS 1   s  forming the frame shape of the rear case CS 1 . This, however, is not meant as a limitation; for example, the ribs RB may be formed on the two long ones of the side walls CS 1   s  forming the frame shape. 
     Here, it is preferable that, as shown in  FIG. 4 , the ribs RB be formed on one and the other of a pair of opposing side walls CS 1   s  such that the ribs RB also each face a corresponding one of the other ribs RB, in the same manner that the opposing side walls CS 1   s  face each other. 
     This is because, with this arrangement, pressure applied to the touch panel  79  when touch input is performed thereon is effectively dispersed (that is, the touch panel  79  is stably supported by the ribs RB). Furthermore, to disperse the pressure applied to the touch panel  79  even more effectively, the ribs RB may be formed on all the side walls CS of the rear case CS 1 . 
     In the internal frame FM and the front case CS 2 , the opening portions formed for the ribs RB to pass therethrough may be formed as apertures like the frame apertures FMo and the case apertures CS 2   o , but this is not meant to limit the present invention. For example, the opening portions formed in the internal frame FM and the front case CS 2  may be formed as cuts (the frame opening portion, the case opening portion). The point is that the ribs RB are securely kept out of contact with the internal frame FM and the front case CS 2  to thereby prevent pressure applied via the touch panel  79  from being transmitted to the internal frame FM and the front case CS 2 . 
     The ribs RB do not need to be placed through the opening portions (the frame apertures FMo and the case apertures CS 2   o ) formed in the internal frame FM and the front case CS 2 . For example, it can be said that the opening portions are not necessary if the ribs RB are formed on outer side surfaces of the side walls CS 1   s  such that they are allowed to be in contact (for example, a direct contact or an indirect contact via the cushion sheet  72 ) with the touch panel  79  without being in contact with the internal frame FM and the front case CS 2 . 
     LIST OF REFERENCE SYMBOLS 
     
         
         
           
             RB rib [support portion] 
             CS case 
             CS 1  rear case [first case] 
             CS 1   s  side wall of rear case 
             CS 2  front case [second case] 
             CS 2   u  support surface of front case 
             CS 2   o  case aperture [case opening portion] of front case 
             FM internal frame [frame] of backlight unit 
             FMu support surface of the internal frame 
             FMo frame aperture [frame opening portion] of internal frame 
             FMt protrusion 
               49  backlight unit 
               59  liquid crystal display panel [display panel] 
               69  display unit 
               71  cushion sheet 
               79  touch panel 
               89  liquid crystal display device [display device]