Patent Publication Number: US-2007103617-A1

Title: Display unit

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a display unit that includes a liquid crystal display panel and a lighting device that causes a light to be incident on a side surface of the liquid crystal display panel.  
      2. Description of the Related Art  
      A liquid crystal display panel is not a self-luminous display unit. In a dark environment in which a sufficient external light cannot be secured, therefore, a visibility of the liquid crystal display panel should be improved using an auxiliary light source.  
      As a first example of a display unit that employs such an auxiliary light source, a display unit constituted so that a light guide plate is superposed on an upper portion of the liquid display panel, a linear lighting device is arranged on a side surface of the light guide plate, a light from the lighting device is caused to be incident on the side surface of the light guide plate, and that the light is thereby irradiated from this light guide plate onto an entire surface of the liquid crystal display panel is described in Japanese Patent Application Laid-Open No. 2001-356323. The light guide plate and the liquid crystal display panel are both fixed to a common fixing frame.  
      As a second example of the display unit that employs the auxiliary light source, a display unit constituted so that a lighting device (a light source) is arranged on a side surface of a liquid crystal display panel (a liquid crystal cell), and that a light from the lighting device is caused to be incident on the liquid crystal cell is described in Japanese Patent Application Laid-Open No. 2001-33766. The display unit in the second example is characterized in that a structure of the display unit can be simplified and a size of the display unit can be reduced since it is unnecessary to arrange a light guide plate above the liquid crystal display. In the second example, it is necessary to ensure that the light from the lighting device is accurately incident on the liquid crystal display panel. To do so, a positional relationship between the lighting device and the liquid crystal display panel should be accurately held. However, the above Japanese patent document fails to describe a structure intended to consider that respect.  
     SUMMARY OF THE INVENTION  
      According to a first aspect of the present invention, there is provided a display unit comprising: a liquid crystal display panel; a lighting device arranged to face one side surface of the liquid crystal display panel, and causing a light to be incident on the side surface of the liquid crystal display panel; and a single support frame that supports the liquid crystal display panel and the lighting device.  
      The support frame may comprises a flat portion that supports the liquid crystal display panel; and a holding portion that is formed by bending one side edge of the flat portion, and that supports the lighting device. The lighting device comprises a linear light guide member; and a point light source arranged on one end surface of the light guide member. At least the linear light guide member is arranged in the holding portion.  
      According to a second aspect of the present invention, there is provided a display unit comprising: a circuit board; a liquid crystal display panel arranged to be superposed on the circuit board; a lighting device that is arranged to face one side surface of the liquid crystal display panel, and that causes a light to be incident on the side surface of the liquid crystal display panel; and a single shield member that is arranged between the circuit board and the liquid crystal display panel, and that shields both of or one of an electricity and a magnetism, wherein the shield member supports both the liquid crystal display panel and the lighting device.  
      The shield member may comprise a flat portion that supports the liquid crystal display panel; and a holding portion that is formed by bending one side edge of the flat portion, and that supports the lighting device. The lighting device comprises a linear light guide member, and a point light source arranged on one end surface of the light guide member, and at least the linear light guide member is arranged in the holding portion of the shield member.  
      As stated above, according to the present invention, the liquid crystal display panel and the lighting device are supported by one frame, and a light emitted from this lighting device is incident on the side surface of the liquid crystal display panel. Therefore, the position of the lighting device relative to the liquid crystal display panel is stabilized, and it is possible to cause the light to be stably incident on the side surface of the liquid crystal display panel from a correct position in a correct direction. As the frame that supports the liquid crystal display panel and the lighting device, a single shield member that is arranged between the circuit board and the liquid crystal display panel, and that shields both of or one of an electricity and a magnetism can be used. In addition, if the lighting device is composed by the linear light guide member and the point light source, the linear light guide member (and the reflecting member) can be stored in a portion formed by folding one side of the frame (shield member). 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and other objects and features of the present invention will be readily apparent from the following description of embodiments with reference to the accompanying drawings, in which  
       FIG. 1  is a perspective view of a wristwatch type display unit according to the present invention, composed by a module that includes a display portion, a bezel to which the module is attached, and a band integral with the bezel;  
       FIG. 2  is a front view which depicts a state in which the display unit shown in  FIG. 1  is put on a cradle indicated by a dotted line and in which a secondary battery in the module is charged;  
       FIG. 3  is an exploded view which depicts a state in which the display unit shown in  FIG. 1i s disassembled and seen upside down and which explains that an electronic apparatus is assembled by fitting the module into the bezel integral with the band;  
       FIG. 4  is an exploded view which depicts a state in which the module shown in  FIG. 3  is disassembled to show constituent elements of respective portions;  
       FIG. 5  is a perspective view which depicts a base frame that constitutes the module shown in  FIG. 3  from below;  
       FIG. 6  is a perspective view of a contact plate attached between a circuit board and an intermediate frame constituting the module shown in  FIG. 3 ;  
       FIG. 7  is a perspective view of the intermediate frame that constitutes the module shown in  FIG. 3 ;  
       FIG. 8  is a perspective view of a shield member that constitutes the module shown in  FIG. 3 ;  
       FIG. 9  is a perspective view of a panel member that constitutes the module shown in  FIG. 3 ;  
       FIG. 10  is a plan view which depicts the module shown in  FIG. 3  from above;  
       FIG. 11  is a plan view which depicts the module shown in  FIG. 3  from below;  
       FIG. 12  is an internal view of a rear cover shown in  FIG. 3 ; and  
       FIG. 13  is an explanatory view for uniformly illuminating an entire display portion of the panel member in the display unit shown in  FIG. 1 . 
    
    
     DESCRIPTION OF THE EMBODIMENTS  
       FIG. 1  depicts a wristwatch type display unit  1 , which functions as an information terminal that can acquire e-mail and Internet information and that can store and edit data. This display unit  1  is composed by a module  2  that includes a display portion, a bezel  3  to which the module  2  is attached, a band  4 , and a rear cover  5 . The bezel  3  is an external frame of the module  2 . In this embodiment, the bezel  3  and the band  4  are formed integrally with each other using a synthetic resin. As shown in  FIG. 3 , the bezel  3  is in the form of a container, and provided with a first stepped portion  6  to which the module  2  is attached and a second stepped portion  7  into which the rear cover  5  is fixedly fitted.  
      The display unit  1  includes a lithium battery (secondary battery) and a small secondary coil, both of which will be described later, in the module  2 . As shown in  FIG. 2 , the display unit  1  is mounted on a cradle  8 , whereby a primary coil  9  in the cradle  8  is electromagnetically coupled with the secondary coil in the module  2 , and a lithium battery is charged using an induction electromotive force. The lithium battery is a light source for the entire display unit  1 .  
      A thin conductive strip is embedded in each of the bands  4 , thereby forming antennas  10 . One end  11  of each antenna  10  is put on the first stepped portion  6  and exposed into the bezel  3 . The end  11  of the antenna  10  is connected to an antenna terminal (a surface pattern on the circuit board) exposed toward the module  2  when the module  2  is attached to the bezel  3 . The other ends of the respective antennas  10  are connected to each other when the bands  4  are wound around a wrist and the both ends are connected to each other. A loop is thus formed and the loop functions as the antenna.  
      As shown in  FIG. 2 , three buttons  12   a ,  12   b ,  12   c  are provided on a front surface of a side surface of the bezel  3  for operating the module  2 .  FIG. 3  shows that holes  13   a ,  13   b , and  13   c  through which rods of these buttons  12   a ,  12   b , and  12   c  are penetrated are formed on a sidewall of the bezel  3 . As shown in  FIG. 3 , two buttons  12   d  and  12   e  are provided on a back surface of the side surface of the bezel  3 .  
      As shown in  FIG. 4 , the module  2  includes a fixing frame  14 , a panel member  15 , a shield member  16 , an intermediate frame  17 , a circuit board  18 , and a base frame  19  in this order from above. In  FIG. 4 , reference numeral  20  denotes a linear light guide member, and reference numeral  21  denotes a reflecting member. These members  20  and  21  constitute an indirect linear lighting device. Reference numeral  22  denotes a lithium battery. Reference numeral  23  denotes a secondary coil, which is contained in a case and two terminals protrudes from the case.  
      Structures of main elements that constitute the module  2  will be described with reference to  FIG. 4  and relevant drawings.  
      [Base Frame: ( FIG. 5 )] 
      The base frame  19  is formed by an ABS resin having a high strength and a high forming accuracy, and includes a battery storage recess  25  that opens downward in a central portion of the base frame  19 . A depth of the battery storage recess  25  is substantially equal to a thickness of the lithium: battery  22 . The lithium battery  22  is fitted into this battery storage recess  25  from below. A bottom of the battery storage recess  25  is cut out so as to radiate a heat, reduce a weight, and to be used as a resonant space for a piezoelectric buzzer.  
      Support base portions  26   a  and  26   b  protrude outward of a left side and a right side of the base frame  19 , respectively. An attachment base  27  for the secondary coil  23  protrudes outward of a front side of the base frame  19 . The attachment base  27  for the secondary coil  23  is arranged not to be superposed on the battery storage recess  25  two-dimensionally.  
      The secondary coil  23  is attached to a lower surface of the attachment base  27 . A positioning hook protrusion  28  and a pair of vertical pins  29   a  and  29   b  are formed on the lower surface of the attachment base  27 . Firstly the case that stores the secondary coil  23  therein is provided so that two sides of the case butt on the vertical pins  29   a  and  29   b  respectively and one end of the case is engaged with the hook protrusion  28  to position the case in a vertical direction and a horizontal direction. Through these procedures, the case that stores therein the secondary coil  23  is positioned relative to the attachment base  27  in the vertical direction and the horizontal direction.  
      As stated, in the display unit, the secondary coil and the lithium battery (secondary cell) are arranged not to be superposed on each other two-dimensionally. Therefore, efficiency for coupling the secondary coil with the lithium battery by electromagnetic induction is improved without interference with each other.  
      The secondary coil  23  needs to be accurately positioned in the vertical direction and the horizontal direction so that the secondary coil  23  is electromagnetically coupled with the primary coil  9  in the cradle  8  ( FIG. 2 ). It is, therefore, important to set a position and a thickness of the attachment base  27  in the base frame  19 .  
      A recess  30  to which a positioning protrusion  39  of a contact plate  37  ( FIG. 6 ), to be described later, retreats is formed at a position near the attachment base  27  of the base frame  19 . A lead wire of the lithium battery  22  is connected to a connector  59  through an upper portion of the base frame  19  in  FIG. 11  to be described later.  
      A positioning protrusion  31  and a vertical pin  32  for positioning the circuit board  18  thus mounted protrude from an upper surface of the base frame  19 . Further, notches  33  for exposing a contact surface provided on an edge of the circuit board  18  (or a pattern formed on the circuit board  18 ) are formed on the upper surface of the base frame  19 .  
      [Circuit Board] 
      The circuit board  18  includes a printed circuit board, a CPU, a memory, parts responsible for input and output, and the like arranged on the printed circuit board, and a reception circuit for receiving a radio wave. The circuit board  18  is rectangularly flat, and includes flange portions  34   a  and  34   b  having shapes and sizes matched to the support base portions  26   a  and  26   b  of the base frame  19  on left and right sides of the circuit board  18 , respectively. Meshed circuit patterns  36   a  and  36   b  are formed widely into sheets on these respective flange portions  34   a  and  34   b.  A liquid crystal display panel  53 , to be described later, and the linear light guide member  20  are arranged to be superposed on each other in a central portion of the circuit board  18  except for the flange portions  34   a  and  34   b.  Further, three contact surfaces  35   a ,  35   b,  and  35   c  are formed on a front edge of the circuit board  18 , and two contact surfaces  35   d  and  35   e  are formed on a rear edge of the circuit board  18 . A grounding surface pattern portion of the circuit board  18  is formed into a mesh.  
      The three contact surfaces  35   a ,  35   b , and  35   c  formed on the front edge of the circuit board  18  face contact pieces  38   a ,  38   b,  and  38   c  formed on the contact plate  37  ( FIG. 6 ), respectively. This contact plate  37  is a separate member from the circuit board  18 , and attached between the circuit board  18  and the intermediate frame  17  while the protrusion  39  is engaged with the intermediate frame  17 . When being depressed by buttons  12   a ,  12   b , and  12   c  shown in  FIG. 2 , the contact pieces  38   a ,  38   b,  and  38   c  come in contact with the contact surfaces  35   a ,  35   b , and  35   c  of the circuit board  18 , respectively.  
      [Intermediate Frame: ( FIG. 7 )] 
      The intermediate frame  17  is provided to form a gap between the circuit board  18  and the panel member  15 , and to protect the parts protruding on the circuit board  18 . The shield member  16  and the panel member  15  are superposed on the intermediate frame  17 , and the fixing frame  14  is further covered on the panel member  15 . At this time, spring hooks  40   a ,  40   b ,  40   c  and  40   d  provided on left and right sides of the fixing frame  14  are engaged with engagement protrusions  41   a ,  41   b ,  41   c  and  41   d  provided to slightly protrude in four corners of the base frame  19  (note, however, that the engagement protrusion  41   d  is invisible in  FIG. 4 ), respectively. By this engagement, the intermediate frame  17  and the circuit board  18  are fixed to each other while being compressed between the fixing frame  14  and the base frame  19 .  
      As shown in  FIG. 7 , guide protrusions  42   a ,  42   b ,  42   c  and  42   d  that include inclined surfaces for guiding the hooks  40   a ,  40   b ,  40   c  and  40   d  of the fixing frame  14  to the engagement protrusions  41   a ,  41   b ,  41   c  and  41   d  of the base frame  19 , respectively, are provided on left and right sides of the intermediate frame  17  (note, however, that the guide protrusions  42   a  and  42   b  are invisible in  FIG. 7 ). Further, a pair of protrusion guides  43   a  and  43   b  are formed on the right side of the intermediate frame  17 , and a pair of engagement holes  44   a  and  44   b  are formed on the left side of the intermediate frame  17 . The protrusion guides  43   a  and  43   b  and the engagement holes  44   a  and  44   b  are used for positioning the shield member  16  relative to the intermediate frame  17 . In addition, a plurality of spacer protrusions  45  are formed on an upper surface of the intermediate frame  17 .  
      [Shield Member: ( FIG. 8 )] 
      The shield member  16  is provided to protect a liquid crystal drive control portion  54  ( FIG. 9 ) of the liquid crystal display panel, to be described later, that constitutes the panel member  15  from an electromagnetic noise from the circuit board  18 . The shield member  16  is a thin stainless steel frame member. Since the shield member  16  is the member that shields at least one of an electricity and a magnetism as stated above, an area of a punched part is made as small as possible. As shown in  FIG. 9 , the liquid crystal drive control portion  54  of the liquid crystal display panel is provided on a flexible printed circuit (FPC)  55  arranged on a lower surface of the liquid crystal display panel  53 .  
      A holding portion  46  having a U-shaped cross section is formed on a right side of the shield member  16  by vertically raising a right side portion of the shield member  16  over its entire length and then bending the right side portion inward. On the other hand, protrusion pieces  48   a  and  48   b  inserted into the engagement holes  44   a  and  44   b  of the intermediate frame  17  protrude outward of a left side of the shield member  16 . One engagement piece  49  is formed downward of a front side of the shield member  16 . A pair of protrusions are formed to protrude outward and bend downward of a rear side of the shield member  16 , and contact pieces  47   a  and  47   b  are formed on one side ends of parts bent downward of the paired protrusions, respectively. The contact pieces  47   a  and  47   b  are depressed by the buttons  12   d  and  12   e  shown in  FIG. 3  to be brought into contact with the contact surfaces  35   d  and  35   e  of the circuit board  18 , respectively. A central portion of the shield member  16  except for the holding portion  46 , the contact pieces  47   a  and  47   b , the protrusion pieces  48   a  and  48   b , and the engagement protrusion  49  is formed into a flat portion.  
      Each of the contact pieces  47   a  and  47   b  and the engagement protrusion  49  exhibits a spring performance. When the shield member  16  is forced into the intermediate frame  17  from above, the front and rear sides of the intermediate frame  17  are put between the contact pieces  47   a  an  47   b  and the engagement protrusion  49 . Therefore, the shield member  16  can be-stably held into the intermediate frame  17 .  
      As shown in  FIG. 8 , a stopper  50  having a tip end bent downward protrudes from a rear end of an upper portion of the holding portion  46 -formed on the right side of the shield member  16  and having the U-shaped cross section, and an LED fixing piece  51  protrudes from a front end of the upper portion of the holding portion  46 .  
      The linear light guide member  20  is a transparent rectangular solid. The linear light guide member  20  is stored in the holding portion  46  while being put between parts of the reflecting member  21  bent to have a U-shaped cross section. Namely, the linear light guide member  20  and the reflecting member  21  between parts of which the member  20  is put are inserted into the holding portion  46  from a front end of the holding portion  46  (or from an end portion on a side on which the LED fixing piece  51  is formed), slidably moved in the holding portion  46 , and positioned relative to the holding portion  46  while one end of the linear light guide member  20  and one end of the reflecting member  21  butt on the stopper  50 .  
      Further, the shield member  16  includes a tongue piece  52  having a spring performance and bent downward so as to be grounded. A lower end of this tongue piece  52  is designed to come in contact with a grounding surface pattern portion of the circuit board  18  when the assembling of the module is completed.  
      [Panel Member: ( FIG. 9 )] 
      The panel member  15  is composed by the liquid crystal display panel  53  and the FPC  55  that includes the drive control portion  54  for the liquid crystal display panel  53 . Each cell of the liquid crystal display panel  53  is not a square but normally a rectangle having left and right sides, which are long sides, and front and rear sides, which are short sides, as shown in  FIG. 9 . Therefore, a connection portion in which the FPC  55  is connected to the liquid crystal display panel  53  is arranged on the left side of the panel member  15  corresponding to one of the long sides of the liquid crystal display panel  53 . In addition, the holding portion  46  that stores therein the linear light guide member  20  and the reflecting member  21  is arranged on the right side of the shield member  16  corresponding to the other long side of the liquid crystal display panel  53 . The entire module  2  is thereby formed into a shape similar to a square, whereby a shape balance as the display unit is kept.  
      As shown in  FIG. 9 , a first branch portion  58   a  and a second branch portion  58   b  are branched from a main portion of the FPC  55 . A connector portion  56  (connection line) connected to the circuit board  18  is provided on a tip end of the first branch portion  58   a , and an LED  57  (a point light source) is attached to a tip end of the second branch portion  58   b.  The main portion of the FPC  55  is bent and superposed on a rear surface of the liquid crystal display panel  53 . The liquid crystal drive control section  54  is formed in the main portion of the FPC  55 .  
      By twisting the second branch portion  58   b,  the LED  57  is located on a front end of the right side of the liquid crystal display panel  53 , that is, located on a front end of the shield member  16  (the holding portion  46 ). A light emitting surface of the LED  57  is directed rearward and in contact with the end of the linear light guide member  20  held in the holding portion  46  of the shield member  16 .  
      Rear ends of the linear light guide member  20  and the reflecting member  21 , attached into the holding portion  46  of the shield member  16 , are stopped by the stopper  50  so as to prevent detachment, and front ends thereof are temporarily stopped by the LED fixing piece  51 . A second stopper  61  ( FIG. 4 ) formed downward on a front side of the fixing frame  14  abuts on an outside of this LED fixing piece  51 , thereby pressing down the LED fixing piece  51  that temporarily stops the linear light guide member  20  and the reflecting member  21 , from outside.  
      [Formation of Module]The circuit board  18 , the intermediate frame  17 , the shield member  16 , and the panel member  15  are sequentially stacked on the base frame  19  in this order. The fixing frame  14  is covered on the panel member  15 , and the circuit board  18 , the intermediate frame  17 , the shield member  16 , and the panel member  15  are fastened between the panel member  15  and the base frame  19 , thereby forming the module  2 .  
      To form this module  2 , the linear light guide member  20  and the reflecting member  21  are incorporated into the holding portion  46  of the shield member  16  in advance. The panel member  15  is superposed on the shield member  16 , the LED  57  is put on the front end of the holding portion  46 , and the LED fixing piece  51  is crimped, thereby fixing the LED  57  into the holding portion  46 .  
      The FPC  55  of the liquid crystal display panel  53  is folded so that the drive control portion  54  is located below the liquid crystal display panel  53 . The connector portion  56  on the tip end of the FPC  55  is inserted downward from the central punched part of the shield member  16 , thereby coupling the connector portion  56  with a connector of the circuit board  18 .  
      When the panel member  15  is attached to the shield member  16 , the right side of the panel member  15  is connected to one end surface of the linear light guide member  20  stored in the holding portion  46  of the shied member  16 . As a result, the display portion of the panel member  15  receives a light from the LED  57  through the linear light guide member  20  and also receives a light (leakage light) reflected by the reflecting member  21 . How the display portion of this panel member  15  is illuminated will now be described in detail with reference to  FIG. 13 .  
      A substrate  71  of the panel member  15  is composed by a liquid crystal panel upper glass  73  and a liquid crystal panel lower glass  74 . The upper glass  73  is arranged to be superposed on the lower glass  74  with a liquid crystal gap  72  put there between. A thin sheet light guide member  76  (prism sheet) is formed between a surface of the substrate  71  and an upper polarizer  75 . A reflecting plate  78  is bonded to a rear surface of the substrate  71  through a lower polarizer  77 . A light emitted from the LED  57  is incident on a side surface of the substrate  71  of the panel member  15  from the linear light guide member  20 , guided from right to left of the panel member  15  shown in  FIG. 9  while being reflected and refracted between the sheet light guide member  76  on the surface of the panel member  15  and the reflecting plate  78  on the rear surface of the substrate  71 , whereby the entire display portion of the panel member  15  is uniformly illuminated. According to this embodiment, therefore, as shown in  FIG. 13 , (1) the linear light guide member  20  is connected to the side surface of the substrate  71  that constitutes the panel member  15 . In addition, (2) the light emitted from the LED  57  and incident on the side surface of the substrate  71  of the panel member  15  is illuminated on the entire surface of the substrate  71  while being reflected between the sheet light guide member  76  on the surface of the substrate  71  and the reflecting plate  78  on the rear surface of the substrate  71 , and using the substrate  71  itself as a part of the light guide member. In the example of  FIG. 13 , the linear light guide member  20  is connected to only the side surface of the liquid crystal panel upper glass  73  that constitutes the substrate  71 . Alternatively, the linear light guide member  20  may be connected to the side surface of the liquid crystal panel upper glass  73  and that of the liquid crystal lower glass  74 . As can be seen, the panel member  15  is connected to the linear light guide member  20 , while the panel member  15  and the linear light guide member  20  are positioned based on the shield member  16 . Therefore, the connection between the panel member  15  and the linear light guide member  20  is accurately made.  
      As is obvious from  FIGS. 10 and 11  which depict the completed module  2  from above and below, respectively, the main part of the module  2  is substantially square in a plain view. The support base portions  26   a  and  26   b  of the base frame  19  protrude from left and right sides of the main part of the module  2 , respectively. As shown in  FIG. 10 , the meshed circuit patterns  36   a  and  36   b  are formed on upper surfaces of the left and right support base portions  26   a  and  26   b , respectively. When the module  2  is viewed from below, the lithium battery  22  and the secondary coil  23  are seen as shown in  FIG. 11 . In  FIG. 11 , reference numeral  59  denotes a connector, which connects the circuit substrate  18  to the lithium battery  22 .  
      The completed module  2  is fitted into the bezel  3  integral with the bands  4 . Reinforcing members  60   a  and  60   b  are fitted to the left and right support base portions  26   a  and  26   b  of the base frame  19  and fixed thereto by screws. At this time, the flange portions  34   a  and  34   b  of the circuit board  18  are located above the left and right support base portions  26   a  and  26   b  of the base frame  19 . The meshed circuit patterns  36   a  and  36   b  formed on the flange portions  34   a  and  34   b  are connected to the antenna ends  11  of the bands  4 , thereby connecting the antennas  10  to the circuit of the circuit board  18 , respectively. The rear cover  5  is covered on the module  2  and fixed onto the module  2  by screws.  
      The rear cover  5  consists of the same synthetic resin as that for the bezel  3 . As shown in  FIG. 12 , the piezoelectric buzzer  61  consisting of piezoceramic or the like is arranged on an inside surface of the rear cover  5 . This piezoelectric buzzer  61  is located below the lithium battery  22  so as to avoid superposition of the buzzer  61  on the secondary coil  23  attached to the lower surface of the attachment base  27  of the base frame  19  as much as possible. In other words, the attachment base  27  for attaching the secondary coil  23  is arranged at a position so that the attachment base  27  is not superposed on the piezoelectric buzzer  61  two-dimensionally.  
      A space between the rear cover  6  and the lithium battery  22  as well as the bottom of the battery storage recess  25  forms the resonant space for the piezoelectric buzzer  61 .  
      Finally, the rods of the buttons  12   a to  12   c  ( FIG. 2 ) and the buttons  12   d  and  12   e  ( FIG. 3 ) are inserted from the through holes  13   a to  13   c  and the through holes  13   d  and  13   e  (note, however, that the through holes  13   d  and  13   e  are invisible in  FIG. 3 ), respectively. The contact pieces  38   a  to  38   c  ( FIG. 6 ) and the contact pieces  47   a  and  47   b  ( FIG. 8 ) are depressed by tip ends of these rods, whereby the contact pieces  38   a  to  38   c  and  47   a  and  47   b  are allowed to come in contact with the contact surfaces  35   a  to  35   e  of the circuit board  18 . The contact pieces  38   a  to  38   c ,  47   a , and  47   b  exhibit spring performances. Therefore, when a force of depressing the buttons  12   a  to  12   e  is weakened, the rods are pushed back and the buttons  12   a  to  12   e  are returned to their original positions.  
      As stated so far, the lighting device and the liquid crystal display panel are both attached to the shield member  16 , and positioned accurately relative to the shield member  16 . Therefore, the lighting device and the liquid crystal display panel can be easily assembled and the illumination can be efficiently utilized.  
      Since the lighting device is directly attached to one side of the liquid crystal display panel, there is no need to provide a light guide plate that ranges over the entire surface of the liquid crystal panel. The display unit can be thereby made thin.  
      Moreover, the lighting device is stored in the holding portion  46  formed as a part of the shield member  16 . Since the lighting device is attached to such a relatively large member, the auxiliary light source can be easily formed. In addition, if the lighting device is constituted to include the linear light guide member  20  and the reflecting member  21 , and the linear light guide member  20  and the reflecting member  21  are inserted into the holding portion  46 , the members  20  and  21  are positioned by the stopper  50 . Besides, since the LED fixing piece  51  is provided, the positioning and fixing of the LED  57  to the linear light guide member  20  can be easily made.