Patent Publication Number: US-7583811-B2

Title: Electro-optical device and electronic apparatus

Description:
RELATED APPLICATION 
   This application claims priority to Japanese Patent Application No. 2004-241929 filed Aug. 23, 2004 which is hereby expressly incorporated by reference herein in its entirety. 
   BACKGROUND OF THE INVENTION 
   1. Technical Field 
   The present invention relates to electro-optical devices and to electronic apparatuses. More particularly, the present invention relates to an electro-optical device that has a favorable sound-production function when being installed in a portable electronic apparatus. 
   2. Related Art 
   In general, electro-optical devices are installed in various electronic apparatuses as display bodies. Further, there are many cases in which the electro-optical devices are installed in various electronic apparatuses together with sound-production bodies, such as speakers or the like. In an electronic apparatus according to the related art, typically, an electro-optical device (for example, a liquid crystal display device) is housed in a case, while being separated from a sound-production body. For example, in a portable electronic apparatus, such as a cellular phone, the electro-optical device and the sound-production body are separately mounted on a substrate that is disposed in the case (for example, see Japanese Unexamined Patent Application Publication No. 2001-168963) or the electro-optical device and the sound-production body are directly fixed to separate places in the case (for example, see Japanese Unexamined Patent Application Publication No. 2002-77346). 
   Further, in order to reduce the size and the thickness, as the sound-production body installed in the above-described electronic apparatus, a piezoelectric sound-production body is used in which a piezoelectric vibrating body formed by laminating a vibration plate and a piezoelectric body is fixed to the case (for example, see Japanese Unexamined Patent Application Publication No. 2002-77346). 
   In recent years, with the progress of the reduction in size of portable electronic apparatus and the increased screen size of display devices, in the structure according to the related art, if a display section and a sound section are disposed to overlap each other, the thickness of the case is inevitably increased. On the other hand, when the display section and the sound section need to be disposed not to overlap each other for the sake of reducing the thickness of the case, the size of the apparatus is inevitably increased. 
   Further, when the sound-production body is disposed in the electronic apparatus, acoustic design in the vicinity of the sound-production body needs to be performed for each case. Accordingly, the design of the case may be restricted. Further, a sufficient reduction in size or thickness of the case cannot be achieved. 
   SUMMARY 
   An advantage of the invention is that it provides an electro-optical device on which an electro-optical panel and a sound-production body can be mounted compactly. Further, another advantage of the invention is that it provides an electro-optical device in which acoustic design of a sound-production body does not need to be performed for the case of an electronic apparatus in which the electro-optical device is installed. 
   According to an aspect of the invention, an electro-optical device includes an electro-optical panel, a sound-production frame that is disposed on a rear surface of the electro-optical panel and that constitutes a sound-production air space, together with the electro-optical panel, and a sound-production vibrating body that is fixed directly to the sound-production frame in the sound-production air space. 
   In accordance with the aspect of the invention, the sound-production frame disposed on the rear surface of the electro-optical panel constitutes the sound-production air space and the sound-production vibrating body is housed in the sound-production air space. Accordingly, the entire device can be constituted compactly. Further, since the sound-production vibrating body is fixed directly to the sound-production frame, acoustic design of the sound-production vibrating body can be performed in a holding body. If necessary, the relationship between the structure of the sound-production frame and the structure of the electro-optical panel may be considered. Therefore, an influence on sound by the design or internal configuration of a case of an electronic apparatus, in which the electro-optical device is installed, can be reduced. As a result, the design of the electronic apparatus, in which the electro-optical device is installed, can be performed unlimitedly. In addition, in the related art, even when the piezoelectric vibrating body is reduced in size and thickness, as described above, since the sound-production body has the structure in which the-sound-production vibrating body is housed in the case, the piezoelectric vibrating body has a significant volume, which obstructs the reduction in size of a portable electronic apparatus. In the aspect of the invention, since the sound-production vibrating body is mounted and fixed directly to a support body, a compact sound-production section can be implemented and thus the electro-optical device can be further reduced in size and thickness. Further, the number of parts can be reduced and thus a manufacturing cost can be reduced. 
   In the electro-optical device according to the aspect of the invention, it is preferable that, when the sound-production vibrating body is fixed to the sound-production frame, the sound-production air space is divided into front and back spaces. Accordingly, the interference between the sound waves occurring in front and back sides of the sound-production vibrating body based on the vibration of the sound-production vibrating body within the sound-production air space can be prevented. Therefore, sound can be efficiently generated. 
   In the electro-optical device according to the aspect of the invention, it is preferable that the sound-production vibrating body is disposed so as to overlap the electro-optical panel in plan view. According to this configuration, the sound-production vibrating body is disposed so as to overlap the electro-optical panel in plan view, and thus the planar size of the electro-optical device can be reduced. 
   In the electro-optical device according to the aspect of the invention, it is preferable that the sound-production vibrating body is a piezoelectric vibrating body that is a laminate of a vibration plate and a piezoelectric body. By using the piezoelectric vibrating body, the electro-optical device can be further reduced in size and thickness. In this case, an outer circumference of the vibration plate is fixed directly to the inner surface of the support body and thus the piezoelectric sound-production body can be constituted by the piezoelectric vibrating body and the support body. 
   The electro-optical device according to the aspect of the invention may further include a panel-holding frame that holds the electro-optical panel. In this case, it is preferable that the sound-production frame is mounted and fixed to the panel-holding frame. According to this configuration, the panel-holding frame that holds the electro-optical panel and the sound-production frame that is mounted and fixed to the panel-holding frame and that constitutes the sound-production air space are mounted and fixed to each other. Therefore, an assembling work or maintenance of the electro-optical device can be easily performed. Here, it is preferable that the sound-production frame is detachably fixed to the panel-holding frame. As a detachable fixing structure, a hook-engagement, press-fit fixing, screw fixing, or the like may be exemplified. 
   The electro-optical device according to the aspect of the invention may further includes a support member that is interposed between the panel-holding frame and the sound-production frame and that defines the sound-production air space. According to this configuration, the sound-production air space can be constituted between the panel-holding frame and the sound-production frame via the support member, and thus the structure and airtightness of the air space can be secured via the support member. Therefore, the sound-production air space can be designed without being limited by the structure of the panel-holding frame or the sound-production frame and thus acoustic design can be easily achieved. Further, a degree of freedom for the structural size of the panel-holding frame or the sound-production frame, or the mounting and fixing structure of the panel-holding frame and the sound-production frame can be secured. 
   In the electro-optical device according to the aspect of the invention, it is preferable that, in the sound-production frame, a fixed inner surface portion that fixes an outer circumference of the sound-production vibrating body and an opposing inner surface portion that faces a vibration side of the sound-production vibrating body are provided. In this case, the opposing inner surface portion may be separated by a space from the vibration side of the sound-production vibrating body. According to this configuration, the outer circumference of the sound-production vibrating body is fixed to the fixed inner surface portion and the opposing inner surface portion faces the vibration side of the sound-production vibrating body while being separated therefrom. Therefore, the sound-production vibrating body can be reliably mounted and fixed, without interrupting the vibration of the sound-production vibrating body. 
   In the electro-optical device according to the aspect of the invention, it is preferable that a step is provided between the fixed inner surface-portion and the opposing inner surface portion, such that the opposing inner-surface portion is separated further from the vibration side of the sound-production vibrating body than from the fixed inner surface portion. According to this configuration, the step is provided between the fixed inner surface portion and the opposing inner surface portion. Therefore, while the outer circumference of the sound-production vibrating body is mounted and fixed to the fixed inner surface portion, the vibration side of the sound-production vibrating body can be reliably separated from the opposing inner surface portion. 
   In the electro-optical device according to the aspect of the invention, it is preferable that a protrusion is formed in the periphery of the opposing inner surface portion, and the fixed inner surface portion is constituted by an upper surface of the protrusion. According to this configuration, the protrusion is provided on the inner surface of the sound-production frame and the sound-production vibrating body is fixed to the protrusion. 
   Moreover, in the support body according to the aspect of the invention, when the opposing inner surface portion is separated from the vibration side of the sound-production vibrating body, a wall portion of a region where the opposing inner surface portion is provided may be protruded outward than a wall portion of a region where the fixed inner surface portion is provided. Further, outer surfaces of both wall portions may be flat. Further, the step may be constituted by allowing the fixed inner surface portion to be protruded inward than the periphery thereof. 
   In the electro-optical device according to the aspect of the invention, it is preferable that an air inlet is provided in the opposing inner surface portion. According to this configuration, with the air inlet, when the sound waves are generated in the sound-production air space by the vibration of the sound-production vibrating body, there is no case in which the vibration of the sound-production vibrating body is suppressed. 
   Further, according to anther aspect of the invention, an electronic apparatus includes the electro-optical device described above, and a control unit that controls the electro-optical device. According to this configuration, since the electro-optical device with the sound-production function can be housed in the electronic apparatus compactly, the electronic apparatus can be reduced in size and thickness. Here, as an electronic apparatus to which the invention can be applied, in particular, a portable electronic apparatus that is needed to be reduced in size is effectively used. As the portable electronic apparatus, a cellular phone, a portable information terminal, an electronic watch, or the like can be exemplified. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements, and wherein: 
       FIG. 1A  is a cross-sectional view of an electro-optical device according to a first embodiment of the invention; 
       FIG. 1B  is a cross-sectional view of the electro-optical device according to the first embodiment of the invention; 
       FIG. 1C  is a plan view of the electro-optical device according to the first embodiment of the invention; 
       FIG. 1D  is a bottom view of the electro-optical device according to the first embodiment of the invention; 
       FIG. 2  is a cross-sectional view of an electro-optical device according to a second embodiment of the invention; 
       FIG. 3  is a cross-sectional view of an electro-optical device according to a third embodiment of the invention; 
       FIG. 4  is a cross-sectional view of an electro-optical device according to a fourth embodiment of the invention; 
       FIG. 5  is a cross-sectional view of an electro-optical device according to a fifth embodiment of the invention; 
       FIG. 6  is a cross-sectional view of an electro-optical device according to a sixth embodiment of the invention; 
       FIG. 7A  is a longitudinal cross-sectional view of a piezoelectric vibrating body; 
       FIG. 7B  is a plan view of a piezoelectric vibrating body; 
       FIG. 8  is a diagram schematically showing the configuration of a control system in an electronic apparatus according to a seventh embodiment of the invention; and 
       FIG. 9  is a perspective view of the electronic apparatus according to the seventh embodiment of the invention. 
   

   DESCRIPTION OF THE EMBODIMENTS 
   Next, embodiments of the invention will be described in detail with reference to the accompanying drawings. Here, the respective embodiments described below are just examples of the invention and the descriptions thereof are not intended to limit the invention. 
   First Embodiment 
     FIG. 1A  is a cross-sectional view taken along one direction (short-side direction) of an electro-optical device  100  according to the invention.  FIG. 1B  is a cross-sectional view taken along the other direction (long-side direction) of the electro-optical device  100 .  FIG. 1C  is a plan view showing the electro-optical device  100 .  FIG. 1D  is a bottom view showing the electro-optical device  100 . The electro-optical device  100  includes a display section  110  that has an electro-optical panel  111  and a sound-production section  120  that has a sound-production vibrating body  121 . 
   The electro-optical panel  111  is constituted by anyone of various electro-optical panels, such as a liquid crystal display panel, an organic electroluminescent panel, a plasma display panel, a field emission panel, and the like. In the present specification, it is assumed that a liquid crystal display panel is used. A backlight  112  that illuminates the electro-optical panel  111  from the back is disposed in the display section  110 . Moreover, when a self-emitting-type panel is used as the electro-optical panel  111 , instead of the liquid crystal display panel, a backlight needs not be used. 
   A panel-holding frame  113  is provided in the display section  110 , and the electro-optical panel  111  and the backlight  112  are held and fixed by the panel-holding frame  113 . A wiring line member  110 P constituted by a flexible wiring board or the like is connected to the display section  110  and is led outside the panel-holding frame  113 . The wiring line member  110 P supplies power or control signals to the electro-optical panel  111  or the backlight  112 . In the panel-holding frame  113 , a sound guiding path  113   b , which is connected to a sound-production air space  120 S to be described below, is provided. The sound guiding path  113   b  opens at the upper surface of the electro-optical device  100  through which the display surface of the electro-optical panel  111  is exposed. 
   In the sound-production section  120 , the sound-production vibrating body  121  and a sound-production frame  122  that constitute the sound-production air space  120 S for housing the sound-production vibrating body  121  are provided. The sound-production vibrating body  121  is a vibrating body that generates sound waves. In this case, unlike a related art speaker, a case or support body that fixes or houses the vibrating body is not provided. The sound-production frame  122  houses the sound-production vibrating body  121  and is detachably fixed to the panel-holding frame  113  of the display section  110 . More specifically, engaging protrusions  113   a  are provided on outer surfaces of the panel-holding frame  113  and engaging openings  122   a  are provided in side walls of the sound-production frame  122 . The engaging protrusions  113   a  are engaged with (fitted into) the engaging openings  122   a , such that the sound-production frame  122  is attached and fixed to the panel-holding frame  113 . Further, a wiring line member  120 P is connected to the sound-production section  120  and is led outside the sound-production frame  122 . The wiring line member  120 P supplies a driving signal to the sound-production vibrating body  121 . 
   A support member  123  is disposed between the panel-holding frame  113  and the sound-production frame  122  so as to define the sound-production air space  120 S. The support member  123  is disposed in a closed curved shape (in the drawing, a ring shape) between the panel-holding frame  113  and the sound-production frame  122 . The inside of the closed curved shape constitutes the sound-production air space  120 S. The support member  123  is preferably made of an elastic material or a buffering material, such as synthetic resin or flexible synthetic resin (for example, urethane foam), such that rattling does not occur between the panel-holding frame  113  and the sound-production frame  122 . Moreover, the present invention is not limited to the present embodiment. Rattling of the support member between the panel-holding frame  113  and the sound-production frame  122  causes undesirable noise and loss of vibration energy of the sound-production vibrating body (piezoelectric vibrating body)  121 , and thus it is preferable to reduce rattling as much as possible. 
   The sound-production vibrating body  121  includes a piezoelectric vibrating body that constitutes a main body of a piezoelectric speaker, for example. As shown in  FIGS. 7A and 7B , the piezoelectric vibrating body is a laminate of a vibration plate  121 S (shim plate) made of stainless steel or the like, and piezoelectric bodies  121 A and  121 B.  FIGS. 7A and 7B  show a bimorph piezoelectric vibrating body in which the piezoelectric bodies  121 A and  121 B are laminated on front and back sides of the vibration plate  121 S. Of course, a unimorph piezoelectric vibrating body may be used. On the surfaces of the piezoelectric bodies  121 A and  121 B, electrodes  121 Ax and  121 Bx made of metal films of gold (Au) or the like, are formed. Conductive pieces l 21 Ay and  121 By made of aluminum or the like are connected to the electrodes  121 Ax and  121 Bx. The conductive pieces  121 Ay and  121 By are connected to a wiring line member  121 C, such as a flexible wiring board or the like. Further, a conductive piece  121 Sy is connected to the vibration plate  121 S and, similarly, is connected to the wiring line member  121 C. The wiring line member  121 C is connected to the wiring line member  120 P. Moreover, the wiring line member  121 C and the wiring line member  120 P may be integrally formed. 
   In the present embodiment, the sound-production vibrating body  121  is fixed directly onto the inner surface of the bottom portion of the sound-production frame  122 . Specifically, an outer edge of the vibration plate  121 S of the sound-production vibrating body  121  is attached and fixed onto the inner surface of the sound-production frame  122 . The outer circumference of the vibration plate  121 S and the inner surface of the sound-production frame  122  are fixed directly to each other via an adhesive or the like. On the inner surface of the sound-production frame  122 , a fixed inner surface portion  122   x , to which the sound-production vibrating body  121  is fixed, and an opposing inner surface portion  122   y  that is provided inside the fixed inner surface portion  122   x  so as to face a vibration side (surface) of the sound-production vibrating body  121  are provided. The opposing inner surface portion  122   y  is configured to be separated by a space from the vibration side of the sound-production vibrating body  121 , that is, such that a gap exists between the surface of the sound-production vibrating body  121  and the opposing inner surface portion  122   y . In the drawing, a step  122   z  is provided between the fixed inner surface portion  122   x  and the opposing inner surface portion  122   y . Due to the step  122   z , the opposing inner surface portion  122   y  is disposed lower than the fixed inner surface portion  122   x.    
   Moreover, in the drawing, with respect to the outer surface of the wall surface on which the fixed inner surface portion  122   x  is provided, the outer surface of the wall surface on which the opposing inner surface portion  122   y  is provided protrudes downward. Here, the outer surfaces are flat. 
   In the present specification, the sound-production air space  120 S means a space that houses the sound-production vibrating body  121  and in which sound waves are generated directly through the vibration of the sound-production vibrating body  121 . In the drawing, the outer circumference of the sound-production vibrating body  121  (the vibration plate  121 S) is fixed airtight to the fixed inner surface portion  122   x  over the entire circumference. Accordingly, the sound-production air space  120 S is divided into an upper space between the sound-production vibrating body  121  and the bottom surface of the panel-holding body  113  and a lower space between the sound-production vibrating body  121  and the opposing inner surface portion  122   y.    
   The upper space of the sound-production air space  120 S is connected to a sound releasing hole  113   c , which is disposed upward, via the sound guiding path  113   b  provided in the panel-holding frame  113 . Sound generated by the vibration of the sound-production vibrating body  121  is released from the sound releasing hole  113   c  above the display section  110 . 
   Further, an air inlet  122   b  is provided in the opposing inner surface portion  122   y . As shown in the drawing, the air inlet  122   b  is preferably formed at the center of the opposing inner surface portion  122   y . Further, as shown in the drawing, a single air inlet  122   b  may be formed. Alternatively, the air inlet  122   b  may be constituted by a plurality of small holes. Here, if the air inlet  122   b  is not provided, the lower space of the sound-production air space  120 S becomes the closed space. In this case, if the volume of the lower space is not sufficiently large, the pressure of air in the lower space is increased by the vibration when the vibration amplitude of the vibration plate is increased. If doing so, the vibration amplitude of the vibration plate is depressed due to the pressure, and thus the sound may not be turned up. If the air inlet  122   b  is formed in the lower space, even when the vibration amplitude of the vibration plate is increased, there is no case in which the vibration amplitude of the vibrating body is depressed, since air moves via the air inlet  122   b . At this time, sound is generated from the air inlet  122   b , but this sound is not used. 
   Moreover, if the lower space has a sufficient volume, the air inlet  122   b  need not be provided. Further, in order to use the sound from the air inlet  122   b , the sound guiding path  113   b  and the sound releasing hole  113   c  need not be provided as long as the upper space has a sufficient volume. 
   The acoustic effect of the sound-production section  120  is suitably designed by adjusting the shape or volume of the sound releasing hole, the sound guiding path, or the sound-production air space  120 S, and the shape or volume of the upper space or the lower space. 
   Further, in the present embodiment, the sound-production vibrating body  121  is disposed to overlap the electro-optical panel  111  in plan view. More specifically, the overall sound-production vibrating body  121  overlaps the electro-optical panel  111  in plan view. Accordingly, the planar size of the electro-optical device  100  can be made small. In the present invention, the electro-optical panel  111  and the sound-production vibrating body  121  need not overlap each other in plan view. 
   In the present embodiment, the display-section  110  having the electro-optical panel  111  and the sound-production section  120  are integrally constituted, and thus a compact electro-optical device  100  can be implemented. Further, since the electro-optical panel and the sound-production body do not need to be separately installed in an electronic apparatus, unlike the related art, an electronic apparatuses in which the electro-optical device  100  is installed can be reduced in size or thickness. Further, the acoustic effect of the sound-production section  120  is determined by the structure of the electro-optical device  100 , and thus the acoustic effect can be prevented from changing according to the arrangement of the sound-production body in the electronic apparatus, unlike the related art. Therefore, acoustic design can be easily achieved and stable sound characteristics can be obtained even when the sound-production body is installed in any electronic apparatus. 
   Further, in the sound-production section  120 , the sound-production vibrating body  121  is fixed directly to the support body between the panel-holding frame  113  and the sound-production frame  122 . Therefore, the sound-production vibrating body that includes a case for housing the sound-production vibrating body does not need to be separately provided. As a result, a more compact sound-production section  120  can be implemented, and the number of parts can be reduced. 
   In particular, since the gap is provided between the vibration side of the sound-production vibrating body and the opposing inner surface portion  122   y , there is no case in which the vibration of the sound-production vibrating body is interrupted, such that the sound waves can be generated in the gap. In this case, when the step  122   z  is provided between the fixed inner surface portion  122   x  and the opposing inner surface portion  122   y , the gap can be secured along the entire vibration side. Further, in order to secure a sufficient volume of the sound emitted from the sound releasing hole  122   b , it is necessary to adjust the gap, but it is convenient to provide the step  122   z  in view of optimization of the gap. 
   Second Embodiment 
   Next, a second embodiment according to the invention will be described with reference to  FIG. 2 .  FIG. 2  is a cross-sectional view taken along one direction (short-side direction) of the electro-optical device  200  according to the second embodiment of the invention. Other parts, which are not shown in  FIG. 2 , can be constituted similarly to those in the above-described first embodiment and thus the descriptions thereof will be omitted. 
   The electro-optical device  200  of this embodiment includes a display section  210  having an electro-optical panel  211  and a sound-production section  220  having a sound-production vibrating body  221 . Here, the electro-optical panel  211 , a backlight  212 , a panel-holding frame  213 , the sound-production vibrating body  221 , and a support member  223  are the same as those in the first embodiment and thus the descriptions thereof will be omitted. 
   In a sound-production frame  222  of the present embodiment, a fixed inner surface portion  222   x  that fixes the sound-production vibrating body  221  and an opposing inner surface portion  222   y  that faces the vibration side of the sound-production vibrating body  221  are provided. The second embodiment is the same as the first embodiment in that a step  222   z  is provided between the fixed inner surface portion  222   x  and the opposing inner surface portion  222   y , but is different from the first embodiment in that a step  222   w  is formed in the periphery of the fixed inner surface portion  222   x  and the fixed inner surface portion  222   x  is provided at a position that is lowered by one step from the inner bottom surface of the periphery thereof. As such, when the fixed inner surface portion  222   x  is constituted to be lowered by one step, the thickness of the sound-production section  220 , excluding a portion where the sound-production vibrating body  221  of the sound-production section  220  is housed, can be reduced and thus the volume of the sound-production  220  can be reduced. Further, like the first embodiment, in the present embodiment, the support member  223  is disposed between the panel-holding frame  213  and the sound-production frame  222 . Alternatively, like the present embodiment, when the fixed inner surface portion  222   x  is lowered from the inner portion of the periphery thereof, a sound-production air space  220 S may be constituted by only the panel-holding frame  213  and the sound-production frame  222 , without disposing the support member  223  therebetween. 
   Third Embodiment 
   Next, a third embodiment according to the invention will be described with reference to  FIG. 3 .  FIG. 3  is a cross-sectional view taken along one direction (short-side direction) of an electro-optical device  300  according to the third embodiment of the invention. In the present embodiment, other parts, which are not shown in  FIG. 3 , can be constituted similarly to those in the above-described first embodiment and thus the descriptions thereof will be omitted. 
   The electro-optical device  300  of this embodiment includes a display section  310  having an electro-optical panel  311  and a sound-production section  320  having a sound-production vibrating body  321 . Here, the electro-optical panel  311 , a backlight  312 , the sound-production vibrating body  321 , and a support member  323  are the same as those in the-second embodiment and thus the descriptions thereof will be omitted. 
   In this embodiment, a panel-holding frame  313  and a sound-production frame  322  are substantially the same as those in the second embodiment and a mounting and fixing structure of the panel-holding frame  313  and the sound-production frame  322  is different from that in the above-described embodiment. In the present embodiment, in outer surfaces of the panel-holding frame  313 , engaging concave portions  313   a  are formed. Further, on side walls of the sound-production frame  322 , engaging protrusions  322   a  are provided to protrude inward. Therefore, if the sound-production frame  322  is fitted into the panel-holding frame  313  from the back, the engaging protrusions  322   a  are elastically engaged with (fitted into) the engaging concave portions  313   a.    
   Like the above-described embodiments or the present embodiment, when the mounting and fixing structure of the panel-holding frame and the sound-production frame is a structure in which the panel-holding frame and the sound-production frame are elastically engaged with (fitted into) each other, an assembling work can be very easily performed. Further, if there is any problem, the sound-production frame can be separated from the panel-holding frame during manufacturing. 
   Fourth Embodiment 
   Next, a fourth embodiment according to the invention will be described with reference to  FIG. 4 .  FIG. 4  is a cross-sectional view taken along one direction (short-side direction) of an electro-optical device  400  according to the fourth embodiment of the invention. In the present embodiment, other parts, which are not shown in  FIG. 4 , can be constituted similarly to those in the above-described first embodiment and thus the descriptions thereof will be omitted. 
   The electro-optical device  400  of this embodiment includes a display section  410  having an electro-optical panel  411  and a sound-production section  420  having a sound-production vibrating body  421 . Here, the electro-optical panel  411 , a backlight  412 , a panel-holding frame  413 , the sound-production vibrating body  421 , and a support member  423  are the same as those in the first embodiment and thus the descriptions thereof will be omitted. 
   In this embodiment, an outer bottom surface of a sound-production frame  422  is flat. Further, an inner bottom surface of the sound-production frame  422  is also flat, but a ring-shaped protrusion (rib)  422   p  that protrudes inward is provided on a portion of the inner bottom surface. At this time, the upper surface of the protrusion  422   p  serves as a fixed inner surface portion  422   x . Thus, an inner surface portion at an inner circumference of the fixed inner surface portion  422   x  serves as an opposing inner surface portion  422   y.    
   In this embodiment, since the outer bottom surface of the sound-production frame  422  is flat, ease of handling can be achieved during a manufacturing process. Further, when the electro-optical device  400  is provided in an electronic apparatus, a gap between the sound-production body  422  and another underlying part (substrate or the like) can be easily secured. Therefore, sound waves emitted from a sound releasing hole  422   b  can be easily transferred to the outside. 
   Fifth Embodiment 
   Next, a fifth embodiment according to the invention will be described with reference to  FIG. 5 .  FIG. 5  is a cross-sectional view taken along one direction (short-side direction) of an electro-optical device  500  according to the fifth embodiment of the invention. In the present embodiment, other parts, which are not shown in  FIG. 5 , can be constituted similarly to those in the above-described first embodiment and thus the descriptions thereof will be omitted. 
   The electro-optical device  500  of this embodiment includes a display section  510  having an electro-optical panel  511  and a sound-production section  520  having a sound-production vibrating body  521 . Here, the electro-optical panel  511  and a backlight  512  are the same as those in the first embodiment and thus the descriptions thereof will be omitted. 
   In this embodiment, a panel-holding frame  513  and a sound-production frame  522  are combined with each other via a screw structure. The screw structure has ring-shaped screw grooves  513   a  provided in the panel-holding frame  513  and ring-shaped screw frames  522   a  provided on the sound-production frame  522 . Then, by rotating the sound-production frame  522  with respect to the panel-holding frame  513 , the ring-shaped screw grooves  513   a  and the ring-shaped screw frames  522   a  are combined with each other, such that the sound-production frame  522  is mounted and fixed to the panel-holding frame  513 . Further, the screws can be simply loosened and removed. 
   In the present embodiment, the panel-holding frame  513  and the sound-production frame  522  are detachably constituted via the screw structure, and thus the assembling work can be easily performed, like the above-described embodiment. Further, when the panel-holding frame  513  and the sound-production frame  522  are mounted and fixed to each other, both can be fixed airtight. Therefore, the support member does not need to be used, unlike the above-described embodiments, and the number of parts can be reduced. As a result, the assembling work can be easily performed. 
   Sixth Embodiment 
   Next, a sixth embodiment according to the invention will be described with reference to  FIG. 6 .  FIG. 6  is a cross-sectional view taken along one direction (short-side direction) of an electro-optical device  600  according to the sixth embodiment of the invention. In the present embodiment, other parts, which are not shown in  FIG. 6 , can be constituted similarly to those in the above-described first embodiment and thus the descriptions thereof will be omitted. 
   The electro-optical device  600  of this embodiment includes a display section  610  having an electro-optical panel  611  and a sound-production section  620  having a sound-production vibrating body  621 . Here, the electro-optical panel  611 , a backlight  612 , and the sound-production vibrating body  621  are the same as those in the first embodiment and thus the descriptions thereof will be omitted. 
   In this embodiment, a panel-holding frame  613  and a sound-production frame  622  are adhered and fixed to each other via an adhesive  623 . The adhesive  623  may generally include an acryl-based adhesive or an epoxy-based adhesive. Here, the panel-holding frame  613  and the sound-production frame  622  may be indirectly attached to each other via the support member in the respective embodiments described above. In addition, the panel-holding frame  613  and the sound-production frame  622  may be fixed to each other through a direct deposition, welding, or the like. 
   In the present embodiment, once if the panel-holding frame  613  and the sound-production frame  622  are fixed to each other, it is impossible to separate them from each other, but both can be reliably mounted and fixed to each other. Further, a support body that is constituted by the panel-holding frame  613  and the sound-production frame  622  can have increased rigidity, such that rattling or the like does not occur. 
   Seventh Embodiment 
   An electronic apparatus of a seventh embodiment according to the invention, in which the above-described electro-optical device is installed, will be described with reference to  FIGS. 8 and 9 . In this embodiment, an electronic apparatus that has the above-described electro-optical device  100  as a display unit will be described. Here, the electro-optical devices according to other embodiments can be applied to the present embodiment, like the electro-optical device  100 . 
     FIG. 8  is a diagram schematically showing the overall configuration of a control system (display control system) with respect to the electro-optical device  100  in the electronic apparatus of the present embodiment. The electronic apparatus shown in  FIG. 8  has a display control circuit  290  that includes a display information output source  291 , a display information processing circuit  292 , a power supply  293 , a timing generator  294 , and a light-source control circuit  295 . 
   Further, in the above-described electro-optical device  100 , a driving circuit  111 D that drives the electro-optical panel  111  having the above-described configuration is provided. The driving circuit  111 D is constituted by electronic parts (semiconductor IC and the like) that are mounted directly on the electro-optical panel  111 . Here, in addition to the above-described configuration, the driving circuit  111 D may be constituted by a circuit pattern formed on the surface of the panel or a semiconductor IC chip or circuit pattern mounted on a circuit board that is electrically connected to a liquid crystal panel. 
   The display information output source  291  includes a memory that has the ROM (Read Only Memory), the RAM (Random Access Memory), or the like, a storage unit that has a magnetic recording disc, an optical recording disc, or the like, and a tuning circuit that synchronously outputs digital image signals. The display information output source  291  is constituted to supply display information to the display information processing circuit  292  in a shape of an image signal having a predetermined format based on various clock signals generated by the timing generator  294 . 
   The display information processing circuit  292  includes various known circuits, such as a serial-parallel conversion circuit, an amplification/inversion circuit, a rotation circuit, a gamma correction circuit, a clamping circuit, and the like. The display information processing circuit  292  processes the input display information and supplies resultant image information to the driving circuit  111 D, together with a clock signal CLK. The driving circuit  111 D includes a scanning line driving circuit, a signal line driving circuit, and a test circuit. Further, the power supply  293  supplies predetermined power to the respective parts described above. 
   The light-source control circuit  295  supplies power supplied from the power supply  293  to a light-source section  112   a  of the backlight  112  based on a control signal from the outside. Light emitted from the light-source section  112   a  is incident on a light guiding plate  112   b  and is irradiated from the light guiding plate  112   b  onto the electro-optical panel  111 . The light-source control circuit  295  controls turning-on or -off of each light source of the light-source section  112   a  according to the control signal. Further, the light-source control circuit  295  may control the luminance of each light source. 
   Further, a sound signal output circuit  296  is provided in the electronic apparatus of the present embodiment. The sound signal output circuit  296  sends a sound signal to the sound-production vibrating body  121  based on a control signal from a control circuit (not shown). In the sound-production vibrating body  121 , the vibration is generated based on the sound signal to be supplied and the sound is outputted based on the vibration. 
     FIG. 9  shows an external appearance of a cellular phone that is an embodiment of the electronic apparatus according to the invention. The electronic apparatus  2000  has an operating section  2001  and a display section  2002 . Inside the case of the display section  2002 , a circuit board  2100  is disposed. The above-described electro-optical device  100  is mounted on the circuit board  2100 . Then, the above-described liquid crystal panel  111  can be viewed through the surface of the display section  2002 . Further, a sound output slot  2003  is provided in the display section  2002 . The sound output slot  2003  is constituted such that the sound outputted from the sound-production body  121  to be emitted from the sound releasing hole or to be guided via the sound guiding path can be heard through the inside the case of the display section  2002 . 
   Moreover, it should be understood that the electro-optical device with the sound-production body and the electronic apparatus of the invention are not limited to the above-described embodiments, but various changes can be made within the scope without departing from the subject matter of the invention. For example, though the piezoelectric vibrating body is used as the sound-production vibrating body in the respective embodiments described above, the present invention is not limited to the piezoelectric vibrating body. For example, a suitable vibrating body, such as a vibration plate of an electromagnetic speaker, or the like, may be used as long as it generates sound waves. Further, though the sound-production vibrating body is fixed to the sound-production frame in the respective embodiments described above, the sound-production vibrating body may be fixed to the panel-holding frame (for example, the bottom surface thereof). In this case, of course, the fixed inner surface portion and the opposing inner surface portion are formed on the panel-holding frame.