Abstract:
The present invention provides a symbol illumination apparatus configured to have a symbol such as characters printed on a front surface of a transparent member, and to allow light from a plurality of light sources to pass through an interior of the transparent member from one side of the transparent member, to illuminate the symbol. A lens sheet and a diffused sheet are inserted between the transparent member and the plurality of light sources in the symbol illumination apparatus. This configuration prevents a plurality of light rays from being seen on the bottom of the transparent member.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a symbol illumination apparatus that is arranged to illuminate a symbol such as characters representing a company&#39;s name or the like, and to a video display apparatus, such as a flat panel display, a flat panel color television or the like, using a Plasma Display Panel (PDP), a liquid-crystal panel or the like, to which this symbol illumination apparatus is applied. 
   2. Description of Related Art 
   In the past, in a video display apparatus such as a flat panel display, a flat panel color television or the like, using a PDP, a liquid-crystal panel or the like, a symbol illumination apparatus has been proposed in which a front assembly having a transparent member is provided on the front, and a symbol such as a company logo or the like is printed on the front of this transparent member, and light from a plurality of light sources is arranged to pass through the interior of this transparent member from one side of this transparent member, whereby to illuminate the symbol such as characters to have the symbol seen as if it were shining while floating in the air. 
   SUMMARY OF THE INVENTION 
   However, when, e.g., a plurality of light-emitting diodes are used as the plurality of light sources, a plurality of light rays from these plurality of light-emitting diodes are reflected at the bottom of this transparent member, thus imposing an inconvenience that the quality is impaired. 
   Further, redundant light from the light-emitting diodes as the light sources leaks to another side, e.g., the lower side of this transparent member, for reflection on a stand section of the video display apparatus or a table, thus imposing another inconvenience that leakage of light is noticeable in a dark room or the like. 
   In view of the above points, the present invention is provided to prevent the plurality of light rays from being reflected at the bottom of the transparent member and also to prevent leakage of light. 
   A symbol illumination apparatus of the present invention is configured to have a symbol such as characters printed on a front surface of a transparent member, and to allow light from a plurality of light sources to pass through an interior of the transparent member from one side of this transparent member, to illuminate the symbol. In the symbol illumination apparatus, a lens sheet and a diffusion sheet are inserted between this transparent member and the plurality of light sources. 
   Further, the symbol illumination apparatus of the present invention may have a print with a gradational design provided on an end on another side of this transparent member in the above-recited symbol illumination apparatus. 
   A video display apparatus of the present invention is provided with a front assembly having a transparent member on a front surface thereof. In the video display apparatus, it is configured to have a symbol such as characters printed on a front surface of the transparent member, and to allow light from a plurality of light sources to pass through an interior of the transparent member from one side of this transparent member, to illuminate the symbol. In the video display apparatus, a lens sheet and a diffusion sheet are inserted between the transparent member and the plurality of light sources. 
   The video display apparatus of the present invention may have a print with a gradational design provided on an end on another side of this transparent member in the above-recited video display apparatus. 
   According to the present invention, because of the arrangement that the lens sheet and the diffusion sheet are inserted between the transparent member and the plurality of light sources, a plurality of light rays can no longer be seen, but become even and smooth light to improve the quality. 
   Further, in the case where the print with a gradational design is provided on the end on another side of the transparent member, light no longer leaks to the outside. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded perspective view showing an example of a front assembly as viewed from a rear surface thereof. 
       FIG. 2  is a perspective view showing an example of the front assembly as viewed from the rear surface. 
       FIG. 3  is a front perspective view showing an example of the best mode for carrying out a video display apparatus of the present invention. 
       FIG. 4  is a rear perspective view of  FIG. 3 . 
       FIG. 5  is an exploded perspective view as viewed from the front of  FIG. 3 . 
       FIG. 6  is an exploded perspective view as viewed from the rear of  FIG. 3 . 
       FIG. 7  is a sectional view showing an example of a main portion. 
       FIG. 8  is a configurational diagram showing an example of a main portion of the present invention. 
       FIG. 9  is a perspective view of an example of a main portion as viewed from a side indicated by an arrow A of  FIG. 3 . 
   

   DESCRIPTION OF PREFERRED EMBODIMENTS 
   Examples of the best mode for carrying out a symbol illumination apparatus and a video display apparatus of the present invention will be described below with reference to the drawings. 
     FIG. 3  shows a front perspective view of a video display apparatus according to the present example, and  FIG. 4  shows a rear perspective view of this video display apparatus. The present example is one in which the present invention is applied to a PDP flat panel display. 
   In  FIG. 3 , a reference symbol  1  denotes a front assembly provided on the front, and a reference symbol  2  denotes a filter glass provided on the front of a video display screen of a plasma display panel and incorporated into this front assembly. In  FIG. 4 , a reference symbol  3  denotes a rear cover. It is arranged such that a plasma display panel  4 , and a display drive circuit, a tuner section, speakers  5  and the like thereof are incorporated between the front assembly  1  and the rear cover  3 , as shown in  FIGS. 5 ,  6 . 
   In the present example, it is arranged such that the video display screen of the video display apparatus is, e.g., 42 inches wide, and a depth thereof is set to, e.g., 9.8 cm, which is an extremely thin value. 
   This front assembly  1  is configured such as shown in examples of  FIGS. 1 and 2 .  FIG. 1  is an exploded perspective view of the front assembly  1  as viewed from a rear surface thereof, and  FIG. 2  is a perspective view of the front assembly  1  as viewed from the rear surface. 
   In  FIGS. 1 ,  5 ,  6 , a reference symbol  10  denotes a plate-shaped, rectangular frame having an opening  10   a  that is almost as large as the video display screen. It is arranged such that this frame  10  is formed by injection molding using, e.g., an ABS resin, and is thereafter subjected to gloss coating, for example. 
   Further, in  FIGS. 1 ,  5 ,  6 , reference symbols  11 L and  11 R denote a left speaker mounting plate and a right speaker mounting plate, respectively. These left and right speaker mounting plates  11 L and  11 R are symmetrical, substantially C-shaped, plate-like members, formed by injection molding using a resin. It is configured to mount the speakers  5  onto these left and right speaker mounting plates  11 L and  11 R, respectively. 
   It is arranged such that these left and right speaker mounting plates  11 L and  11 R are slidably engaged with the left side and right side of the frame  10 , respectively. In the present example, a predetermined number of engageable holes  10   b  are provided in left-side and right-side ends of the frame  10 , respectively, by integral molding, and also engageable projections  11 a are provided by integral molding on respective inner ends of the left and right speaker mounting plates  11 L and  11 R in a manner corresponding to the engageable holes  10   b  of this frame  10 , respectively, whereby it is arranged such that the engageable projections  11   a  on the respective inner ends of the left and right speaker mounting plates  11 L and  11 R slidably engage with the engageable holes  10   b  in the left-side and right-side ends of this frame  10 . 
   In  FIGS. 1 ,  5 ,  6 , reference symbols  12 U and  12 D denote upper and lower transparent members, respectively. These upper and lower transparent members  12 U and  12 D each have a predetermined width, and a length measured substantially along the upper side and the lower side of the video display screen, and made by injection molding using a transparent acrylic resin material. 
   It is arranged such that these upper and lower transparent members  12 U and  12 D are slidably engageable with the upper side and the lower side of the frame  10 , respectively. In the present example, a predetermined number of engageable holes  10   c  are provided in upper-side and lower-side ends of the frame  10  by integral molding, respectively, and also engageable projections  12   a  are provided on ends of the upper and lower transparent members  12 U and  12 D which are opposed to the frame  10 , by integral molding in a manner corresponding to the engageable holes  10   c  of this frame  10 , whereby it is arranged such that the engageable projections  12   a  on the opposed ends of the upper and lower transparent members  12 U and  12 D engage with the engageable holes  10   c  in the upper-side and lower-side ends of this frame  10 . 
   In the present example, an upper side of this upper transparent member  12 U is formed to be inverted L-shaped in cross section such as shown in  FIG. 7  to have a smooth surface on a front side of this upper transparent member  12 U, and also a knurling-like line embossing  13  is provided on the upper surface of this inverted L-shaped member. 
   As the knurling-like line embossing  13 , respective ridges are arranged at an angle of inclination of, e.g., 7 degrees, and at a pitch of 0.5 mm. In this case, a thickness t 0  that can satisfactorily form the upper transparent member  12 U formed by injection molding is typically in the order of 4 mm. Although the thickness of  4  mm is rather poor in terms of design, when a width t 1  of the upper surface of this inverted L-shaped member is set to, e.g., 9 mm, an effect is given that the upper transparent member  12 U is apparently seen as thick as 9 mm even if the thickness t 0  of this upper transparent member  12 U is 4 mm. 
   Further, when the upper side of this upper transparent member  12 U is made to be inverted L-shaped, the member  12 U becomes strong and stable also in terms of rigidity. 
   Furthermore, in the present symbol illumination apparatus, a symbol  14  such as characters representing, e.g., a company logo is printed in the middle of the front of the lower transparent member  12 D, as shown in  FIGS. 3 and 8 . The symbol  14  is printed by, e.g., silk screen process printing using an ink obtained by mixing, e.g., medium ink and fluorescent white ink. 
   Furthermore, as shown in  FIG. 8 , a reflecting surface  15  having a predetermined length in the horizontal direction is formed above the symbol  14  printed on the lower transparent member  12 D, and a plurality of, e.g., seven light-emitting diodes (LEDs)  16  as light sources are provided in parallel in a manner corresponding to the reflecting surface  15  of the lower transparent member  12 D, whereby to arrange such that light from the plurality of LEDs  16  passes through the lower transparent member  12 D. 
   In the present example, a lens sheet  17  having a plurality of linear, V-grooves, and a diffusion sheet  18  are laminated and fixed by, e.g., adhesion, on a portion (side-surface light-incident section) through which the light from the plurality of LEDs  16  corresponding to the reflecting surface  15  of the lower transparent member  12 D passes, as shown in  FIG. 8 . 
   As this lens sheet  17  having the plurality of linear, V-grooves, e.g., a “Vikuiti” (trademark) BEF II brightness enhancement film having a plurality of 90° V-grooves and manufactured by Sumitomo 3M Limited may be usable. 
   In the present example, the lens sheet  17  and the diffusion sheet  18  are inserted between the LEDs  16  and the light-incident section of the lower transparent member  12 D, whereby the light from the LEDs  16  hitherto seen as a plurality of light rays illuminates the symbol  14  in the form of even, smooth light, providing satisfactory illumination. 
   Further, in the present symbol illumination apparatus, a silk screen processed print  19  with a gradational design is provided on the lower-side end face of this lower transparent member  12 D, as shown in  FIG. 8 . In this case, as a result of the silk screen processed print  19  with a gradational design, the light from the LEDs  16  no longer leaks to the outside of the lower side of this lower transparent member  12 D. 
     FIG. 9  shows details of the silk screen processed print  19  with a gradational design as viewed from a side indicated by an arrow A of  FIG. 3 . The silk screen processed print  19  with a gradational design includes a section B and sections C on left and right sides contiguous thereto. The section B is printed solidly over such a range as not to leak the light of the LEDs  16  arranged in a manner corresponding to the width of the symbol  14 , to the outside of the lower side of the lower transparent member  12 D. Further, the two sections C are printed with so-called gradation by which the printing density is reduced as they are away from the section B. 
   Furthermore, when silver is used as the color of an ink used for the silk screen processed print  19  with a gradational design, the light from the LEDs  16  is reflected by the silk screen processed print  19  with a gradational design on the lower end face of this lower transparent member  12 D, to substantially double the luminance of the illumination for the symbol  14 , whereby to produce an effect of higher-quality illumination. 
   Therefore, according to the present example, the quality can be improved and leakage of light can be prevented as to the illumination for the symbol  14  which is to be seen as if floating on the flat panel display. 
   Returning to  FIG. 1  again, the front assembly  1  is obtained as follows. First, the engageable projections  12   a  on the ends of the upper and lower transparent members  12 U and  12 D are slidably engaged with the engageable holes  10   c  on the opposed upper-side and lower-side ends of the frame  10 . Next, the engageable projections  11   a  on the respective inner ends of the left and right speaker mounting plates  11 L and  11 R are slidably engaged with the engageable holes  10   b  in the left-side and right-side ends of the frame  10 , respectively. At this time, engageable projections  12   b  having elasticity and projecting from both ends of the upper and lower transparent members  12 U and  12 D that have been slidably engaged with the frame  10  beforehand are fitted into engageable holes  11   b  provided in respective ends of the left and right speaker mounting plates  11 L and  11 R. 
   Next, the rectangular filter glass  2  that is slightly larger than the video display screen of this plasma display panel  4  is arranged at a predetermined location on the rear of this frame  10 , and thereafter, using an upper-side front frame  20   a,  a lower-side front frame  20   b,  left-side and right-side front frames  20   c  and  20   d,  which are made by machining an iron plate, and four corner brackets  21   a,    21   b,    21   c  and  21   d  which are made by machining an iron plate, and further using machine screws or the like, this frame  10 , the left and right speaker mounting plates  11 L and  11 R, the upper and lower transparent members  12 U and  12 D, and the filter glass  2  are fixed integrally, as shown in  FIG. 2 . 
   In the present example, it is arranged such that the plasma display panel  4 , its drive circuit, speakers  5 , and the like are incorporated between the front assembly  1  assembled as shown in  FIG. 2  and the rear cover  3  having a predetermined shape, as shown in  FIGS. 5 ,  6 , and also such that the LEDs  16  are incorporated into the lower transparent member  12 D in such a configuration as shown in  FIG. 8 . 
   According to the present embodiment, the front assembly  1  is formed from a five-piece configuration including the frame  10 , left and right speaker mounting plates  11 L and  11 R, and upper and lower transparent members  12 U and  12 D. As a result, the molding dies for the respective five pieces of the front assembly  1  can be kept small and can thus be relatively inexpensive, and also their manufacturability, dimensional accuracy can be improved, and a novel design based on the five-piece configuration can also be realized. For example, when the video screen is viewed through the upper and lower transparent members  12 U and  12 D, the video screen is seen as if it were floating in the air, to make the audience feel liberated in terms of design. 
   Further, according to the present example, it is arranged such that the frame  10 , left and right speaker mounting plates  11 L and  11 R, and upper and lower transparent members  12 U and  12 D are slidably engaged with each other. As a result, the front assembly can be made thinner in structure, and the video display apparatus can also be made thinner in structure. According to the present embodiment, the video display screen of the PDP flat panel display can be set to, e.g., 42 inches, with its depth being as thin as, e.g., 9.8 cm. 
   Note that the present invention is not limited to the above-described example, but may, of course, be embodied in various other configurations without departure from the scope and spirit of the present invention. 
   The present document contains subject matter related to Japanese Patent Application JP 2004-205208 filed in the Japanese Patent Office on Jul. 12, 2004, the entire contents of which being incorporated herein by reference. 
   It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.