Abstract:
A speaker includes a vibration board and at least one illuminant. The vibration board is made of translucent resin, and provided with light diffusing patterns on at least one side thereof. The illuminant is disposed behind the vibration board in a circular manner.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of Japanese Patent Application No. 2006-83028 filed Mar. 24, 2006 in the Japan Patent Office, the disclosure of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    (1) Field of the Invention 
         [0003]    This invention relates to the technical field of speakers. 
         [0004]    (2) Background Art 
         [0005]    Some techniques have been introduced wherein the effect of electrical decoration is obtained by providing illuminants on a speaker. For example, Unexamined Japanese Patent Publication No. 2001-95074 discloses a speaker wherein light emitted from a light source is radiated on a center cap mounted on a center portion of a vibration board of the speaker, and the light is diffused by a dull finish or the like provided on the inner surface of the center cap. 
         [0006]    However, in the above-described speaker, only the center portion of the speaker is illuminated. Therefore, the visual effect, which can be obtained by the above-described configuration, is limited. 
       SUMMARY OF THE INVENTION 
       [0007]    In one aspect of the present invention, a speaker includes a vibration board and at least one illuminant. The vibration board is made of a translucent resin, and provided with light diffusing patterns on at least one side thereof. The illuminant is disposed behind the vibration board in a circular manner. 
         [0008]    In the above-described speaker, the illuminant is disposed behind the vibration board in a circular manner. Light emitted from the illuminant is diffused by the light diffusing patterns provided on the vibration board, and radiated therefrom. Therefore, the entire area of the vibration board can be used for providing the effect of luminous decoration. 
         [0009]    Since the light emitted from the illuminant is diffused when the light passes through the vibration board, even the number of the light source is small, the entire surface of the vibration board can be illuminated. 
         [0010]    For the vibration board, a sheet of translucent resin, such as polycarbonate, polyethylene, acryl, PET, or the like may be used. The translucency of the sheet may be completely transparent or may be semi-transparent. If the vibration board is completely transparent, the vibration board is brightly illuminated. If the vibration board is semi-transparent, the vibration board is softly illuminated. The translucent resin may be colored with dyes or pigments. 
         [0011]    For the illuminant LED, inorganic EL, organic EL or the like may be used. Various lighting effect can be obtained by, for example, using a multi-color LED and changing the luminous color, or by using a plurality of illuminants and sequentially turning on and off the illuminants. 
         [0012]    The disposition of the illuminant needs to be in a circular manner. However, if a plurality of illuminants is used, the interval between the illuminants is not limited to a specific interval. Alternatively, a circular EL may be used. 
         [0013]    The position for disposing the illuminant may be anywhere behind the vibration board. However, it is preferable that the illuminant is disposed along a outer peripheral of a damper supporting a voice coil. More specifically, a frame of the speaker is provided with a circular flat portion so as to secure an outer edge of the damper, and thus provided with a suitable space outside of the damper for disposing the illuminant. 
         [0014]    The light diffusing patterns may be provided by minute convexes or concaves. For instance, the light diffusing patterns may be formed with a number of linear convexes disposed in parallel, or in a grid manner. The light diffusing patterns may be formed with linear convexes disposed in a diagonal direction in addition to the linear convexes disposed in the grid manner. The light diffusing patterns may be formed with several basic patterns configured with circles, ovals, polygons (triangles, squares, hexagons etc.), or other shapes (star-shapes, diamond shapes etc.) concentrically disposed. The above-described patterns may be formed with linear concaves. Alternatively, the light diffusing patterns can be other patterns apart from the ones exemplified above. 
         [0015]    In a case wherein the light diffusing patterns are formed with linear convexes or concaves, line density (the number of lines per unit length along a width direction of the convexes/concaves) are preferably equal to or higher than 1 line/mm (equal to or smaller than 1 mm pitch). The linear density may be, for example, 2 lines/mm (0.5 mm pitch), 4 lines/mm (0.25 mm pitch), 8 lines/mm (0.125 mm pitch), 10 lines/mm (0.1 mm pitch), and so on. The line density may be even higher. 
         [0016]    Such light diffusing patterns may be provided by pressing the patterns on a sheet made of translucent resin. 
         [0017]    The light diffusing patterns may be provided only on one side of the vibration board. Alternatively, the light diffusing patterns may be provided on both sides of the vibration board. If good audio effect is expected, the light diffusing patterns can be provided only on one side. If the light diffusing patterns are provided on both sides, optical feature in lighting effect can be improved. 
         [0018]    In a case wherein the light diffusing patterns are provided on the both sides of the vibration board, equivalent patterns may be provided on the both sides. However, if each side of the vibration board is provided with a different type of patterns, diffusion manner in each side widely varies. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The invention will now be described below, by way of example, with reference to the accompanying drawings, in which: 
           [0020]      FIGS. 1A to 1D  are diagrams, in which  1 A showing the front view of a speaker according to an embodiment of the present invention, in which  1 B showing the sectional vertical view of the speaker, in which  1 C showing the lateral view of the speaker, and in which  1 D showing the rear view of the speaker; 
           [0021]      FIG. 2  is a diagram showing a first example of light diffusing patterns provided on a vibration board of the speaker according to the embodiment; 
           [0022]      FIG. 3  is a diagram showing a second example of light diffusing patterns provided on a vibration board of the speaker according to the embodiment; 
           [0023]      FIG. 4  is a diagram showing a third example of light diffusing patterns provided on a vibration board of the speaker according to the embodiment; 
           [0024]      FIGS. 5A to 5E  are diagrams respectively showing an example of a shape of linear convexes provided on the vibration board and constituting the light diffusing patterns according to the present embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0025]    First of all, it is to be noted that the present invention is not limited to the following embodiment, and that variations and modifications are possible within the scope of the invention. 
         [0026]    As shown in  FIGS. 1A to 1D , a speaker  1  according to the present embodiment is configured such that respective portions of the speaker  1  are supported by a frame  3 , which is the skeleton of the speaker  1 . The frame  3  with is provided with a square flange  4  in the front end portion thereof. The flange  4  is provided with attachment holes  5 . The speaker  1  can be secured to an application by using the attachment holes  5 . The speaker  1  according to the present embodiment can be, for example, attached to a front frame of a game machine. However, the application of the speaker  1  is not limited to a game machine. The speaker  1  can be used for various applications. 
         [0027]    A back wall  7  of the frame  3  is in a circular shape and provided with a wall hole  9 . A Magnet  10  is attached to a back surface  7   a  of the back wall  7 . A center hole  11  of the magnet  10  is concentric with the wall hole  9 . As shown in  FIG. 1B , the center hole  11  and the wall hole  9  are sequentially connected. 
         [0028]    A bobbin  13  is provided so as to penetrate through the wall hole  9  and the center hole  11 . Around the outer peripheral of the bobbin  13 , a voice coil  12  is wound so as to face the inner peripheral of the magnet  10 . 
         [0029]    To the outer peripheral of the bobbin  13 , an inner peripheral portion of a damper  14  is connected. An outer peripheral portion of the damper  14  is secured to a front surface  7   b  of the back wall  7 . In other words, the bobbin  13  is supported by (the back wall  7 ) of the frame  3  via the damper  14 . The bobbin  13  is disposed concentrically with the wall hole  9  of the back wall  7  and the center hole  11  of the magnet  10 , but is not in contact with the inner peripherals of the back wall  7  and the magnet  10 . The bobbin  13  can be displaced in the axial direction thereof. 
         [0030]    On the front surface  7   b  of the back wall  7 , a circular printed-circuit board  15  is attached along the outer peripheral of the damper  14 . The printed-circuit board  15  is provided with a plurality (twelve, in the present embodiment) of multi-color LEDs  17  arranged thereon with uniform intervals. 
         [0031]    To the front end of the bobbin  13 , a rear end portion of a vibration board  18  is connected. The vibration board  18  is secured to the frame  3  in such a way that an outer peripheral portion of an edge  19  of the vibration board  18  is fixed to the frame  3  by a ring  21 . A center cap  22  is attached inside of the vibration board  18  so as to cover the opening of the bobbin  13 . 
         [0032]    Due to the above-described configuration, when a signal current runs in the voice coil  12 , the vibration board  18  is vibrated via the bobbin  13  around which the vice coil  12  is wound, and sound can be generated. 
         [0033]    The vibration board  18  is made of a sheet of translucent resin, such as polycarbonate, polyethylene, acryl, PET, or the like, and formed into a cone shape. On one side or both sides of the translucent resin sheet, light diffusing patterns, exemplified in  FIGS. 2 to 4 , are provided. 
         [0034]    The light diffusing patterns shown in  FIG. 2  are structured wherein linear convexes are disposed in a vertical, a horizontal, and an oblique directions, that is, in a grid manner. The light diffusing patterns shown in  FIG. 3  are structured wherein linear convexes are disposed in a parallel direction. The light diffusing patterns shown in  FIG. 4  are structured with several basic patterns wherein linear convexes are disposed so as to form various sizes of concentric circles.  FIGS. 5A to 5E  respectively show an example of the shape of the sectional surface of linear convexes constituting the light diffusing patterns. The sectional surface of linear convexes can be in triangle shapes ( FIGS. 5A and 5B ), in trapezoid shapes ( FIGS. 5C and 5D ), in an arc shape ( FIG. 5E ), and so on. 
         [0035]    Therefore, when the multi-color LEDs  17  are illuminated, the light emitted therefrom is diffused by the light diffusing patterns provided on the vibration board  18 , and radiated. As a result, the entire area of the vibration board  18  can be used for providing the effect of luminous decoration. 
         [0036]    Since the vibration board  18  is made of a sheet with light diffusing patterns, and formed into a cone shape, distortion is generated in the light diffusing patterns when the vibration board  18  is formed. Due to the distortion, the patterns of light diffusion widely vary, as compared to a case wherein light is emitted to a flat sheet provided with light diffusing patterns. For example, the degree of brightness is different between the center portion (in the side of the bobbin  13 ) of the vibration board  18  and the outer peripheral portion (in the side of the edge  19 ) of the vibration board  18 . 
         [0037]    Because light emitted from the multi-color LEDs  17  is diffused when the light passes through the vibration board  18 , even if the number if the multi-color LEDs  17  is small with respect to the size of the illuminated area of the vibration board  18 , the entire surface of the vibration board  18  can be illuminated. 
         [0038]    In addition, if the multi-color LEDs  17 , disposed in a circular manner, are made to sequentially emit light in rotation, or to change the color of the light, the effect of diffusion can be changed, and various lighting effects become possible. 
         [0039]    The multi-color LEDs  17  are disposed along the outer peripheral of the damper  14  supporting the voice coil  12 . However, an additional space for providing the multi-color LEDs  17  (printed-circuit board  15 ) on the speaker  1  is not necessary, since a portion in the front surface  7   b  of the back wall  7  where the printed-circuit board  16  is disposed is not used in a conventional speaker. Therefore, the size of the speaker  1  does not become large.