Patent Publication Number: US-8111866-B2

Title: Storage rack

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The present invention contains subject matter related to Japanese Patent Application JP 2006-320665 filed in the Japanese Patent Office on Nov. 28, 2006, the entire contents of which being incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a storage rack incorporating a speaker such as a subwoofer. 
     2. Description of the Related Art 
     An AV (Audio Video) rack incorporating a speaker, an amplifier or the like has been known as a rack capable of mounting or storing a television receiver, an audio apparatus or the like. Lately, home theater systems for enjoying high quality video and audio at home have been widely used. As a result, an amplifier and a speaker provided to such AV rack may correspond to 5.1 or more channels. 
     Right and left speakers at the front, right and left speakers at the rear, a speaker at the center, and a subwoofer for reproducing sound in bass frequencies alone are provided to establish a 5.1 channel surround sound reproduction environment. 
     Japanese Unexamined Patent Application Publication No. 2005-303479 discloses a stand provided with a space for mounting a subwoofer. 
     SUMMARY OF THE INVENTION 
     A subwoofer is responsible for a 0.1 channel out of the 5.1 channels and produces resonance of the air using a bass reflex duct, thereby reproducing sound of low bass frequencies. Hence, the subwoofer may need a space for the resonance of the air. Accordingly, the subwoofer may be large to some extent so that sound in the bass range is reproduced sufficiently. As a result, in the case of mounting the subwoofer to a storage rack as described above, an appearance of the subwoofer may be noticeable and limit the design thereof. 
       FIG. 1  is a front view of an exemplified AV rack  200  including a built-in subwoofer according to related art. The AV rack  200  shown in  FIG. 1  includes: a top board portion  213  on which a television receiver or the like is mounted, leg portions  212   a ,  212   b  supporting the top board portion  213 , and a shelf board  214  extending between the two leg portions  212   a ,  212   b . Further, a subwoofer storage portion  202  including a subwoofer unit  201  is provided at the right end of the AV rack  200 . 
     As shown in  FIG. 1 , the subwoofer storage portion  202  occupies a large part of the AV rack  200  and the portion is noticeable, causing a space for storing audio equipment such as a DVD (Digital Versatile Disc) recorder to be reduced. Therefore, as shown in  FIGS. 2A and 2B , there has been proposed a storage rack in which the subwoofer unit  201  is provided at the rear.  FIG. 2A  is a front view of the storage rack  200  and  FIG. 2B  is a rear view thereof. 
     As shown in  FIG. 2A  (front view), the subwoofer storage portion  202  is provided at the left end of the AV rack  200 . However, the subwoofer storage portion  202  alone is shown to the user, and the subwoofer unit  201  is not shown to the user.  FIG. 2B  is a rear view of the AV rack  200 , showing the subwoofer unit  201  facing the opposite side to the front side shown in  FIG. 2A  to which the user faces. 
     However, in the case where the subwoofer unit  201  is arranged at the rear as shown in  FIGS. 2A and 2B , a reproduction frequency band of the subwoofer unit  201  may have less continuity with those of other speakers (not shown in the figures). For improving the continuity between the respective bands while the subwoofer unit  201  is arranged at the rear, a frequency band of sound reproduced from the other speakers than the subwoofer or the subwoofer unit  201  may need to be extended. Although the continuity may be improved by increasing the volume of a speaker storage portion including a speaker, it is not preferable for the AV rack that stores audio equipment to have a large built-in audio device. 
     It is desirable to provide a storage rack having a speaker such as a subwoofer arranged in a less noticeable position while obtaining a high-quality output sound. 
     According to an embodiment of the present invention, there is provided a storage rack capable of storing an audio apparatus, including a speaker storage portion and a top board portion supporting the audio apparatus. Further, the storage rack includes at least two leg portions for holding the top board portion and a shelf board portion provided in parallel with the top board portion and vertically joined to side surfaces of the two leg portions. A distance between the shelf board portion and the top board portion is adjustable. Further, the speaker storage portion is suspended from the rear surface of the shelf board portion and arranged at the position having a predetermined distance in the depth direction of the shelf board portion. 
     Accordingly, a speaker such as a subwoofer is arranged at the rear under the shelf board portion so that it may be less noticeable when viewed from the front of the storage rack. 
     In the above described case, the speaker storage portion is arranged at the rear in the depth direction of the storage rack. However, since such a member that covers the speaker storage portion is not used, the quality of sound output from the subwoofer or the like can be prevented from being deteriorated. 
     According to the embodiment, a speaker such as a subwoofer can be provided in a less noticeable position without deteriorating the quality of sound output from the speaker. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view illustrating a structure of an AV rack according to related art. 
         FIGS. 2A and 2B  are a front view and a rear view respectively illustrating a structure of an AV rack according to related art. 
         FIG. 3  is a front view illustrating a structure of an AV rack according to an embodiment of the present invention. 
         FIG. 4  is a perspective view illustrating a structure of an AV rack according to an embodiment of the present invention. 
         FIG. 5  is a block diagram illustrating an internal configuration of an AV rack according to an embodiment of the present invention. 
         FIG. 6  is a side view illustrating a position to which a subwoofer box is attached according to an embodiment of the present invention. 
         FIG. 7  is a side view illustrating a structure of an AV rack when a blind screen is attached according to another embodiment of the present invention. 
         FIG. 8  is a front view illustrating an example of attaching a subwoofer box according to an embodiment of the present invention. 
         FIG. 9  is a front view illustrating an example of attaching a subwoofer box according to another embodiment of the present invention. 
         FIG. 10  is a front view illustrating a position where a subwoofer unit is attached according to another embodiment of the present invention. 
         FIG. 11  is a front view illustrating a structure of an AV rack according to another embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described with reference to  FIGS. 3 to 11 . The embodiments are applied to an AV rack (storage rack) including an amplifier that amplifies the sound output from a television receiver and an audio apparatus, a speaker unit outputs the sound, a subwoofer unit reproducing the sound in the frequency band of approximately 40 Hz to 200 Hz. 
     An AV rack  100  shown in  FIG. 3  includes a top board portion  30  on which a television receiver or the like may be arranged and which is held by leg portions  20   a ,  20   b . A shelf board portion  40  is extended between the leg portions  20   a ,  20   b . A plurality of shelf-board supports (not shown in the figure) are provided at predetermined intervals on the side surface of the leg portions  20   a ,  20   b  respectively. The height of the shelf board portion  40  can be adjusted by using the shelf-board supports provided at different heights. Under the shelf board portion  40  is provided a subwoofer box (subwoofer storage portion)  11  incorporating subwoofer units  10 SW- a  and  10 SW- b . The subwoofer box  11  is suspended from the rear (lower) surface of the shelf board portion  40  and held by subwoofer holding portions  42   a ,  42   b . As arranged under the shelf board portion  40 , the subwoofer box  11  is rectangular and has a low height.  FIG. 4  is a perspective view of the AV rack  100 . As shown in  FIG. 4 , the subwoofer box  11  is not seen from the outside and the position thereof is indicated with dotted lines. 
     As shown in  FIG. 3 , the AV rack  100  according to the embodiment further includes an amplifier  50  that amplifies the sound output from a television receiver arranged on the top board portion  30 , an audio apparatus arranged on the shelf board portion  40  and the like, and a speaker unit that outputs the sound amplified at the amplifier  50 . The speaker unit includes a left-rear speaker  10 SL, a left-front speaker  10 FL, a center-front speaker  10 FC, a right-front speaker  10 FR, and a right-rear speaker  10 SR, all of which is arranged within the top board portion  30 . In addition to the speaker unit including the above-described speakers, the subwoofer box  11  including the built-in subwoofer units  10 SW- a  and  10 SW- b  is provided under the shelf board portion  40 , so that the 5.1 channel surround sound environment can be constructed around the user. 
     Next, an internal configuration of the AV rack  100  according to an embodiment of the present invention is described with reference to  FIG. 5 . A reproduced audio signal output from an audio apparatus or the like is supplied to the amplifier  50  from a signal source  1 . In the amplifier  50 , an audio signal of a subwoofer left channel, that of a subwoofer right channel, that of a center channel, that of a left-front channel, that of a right-front channel, that of a left-rear channel, and that of a right-rear channel are supplied to preamplifiers  2 SW- b ,  2 SW- a ,  2 FC,  2 FL,  2 FR, and  2 SR respectively. Audio signals of the respective channels amplified in the preamplifiers  2 SW- b ,  2 SW- a ,  2 FC,  2 FL, and  2 FR, are supplied to amplifiers  5 SW- b ,  5 SW- a ,  5 FC,  5 FL, and  5 FR and output as sound from the speakers  10 SW- b ,  10 SW- a ,  10 FC,  10 FL, and  10 FR. 
     Further, audio signals amplified in the preamplifiers  2 SL and  2 SR for the left-rear channel and right-rear channel are respectively supplied to sound image processing circuits  4 SL,  4 SR where virtual sound image processing is carried out. Audio signals output from the sound image processing circuits  4 SL,  4 SR are supplied to the amplifiers  5 SL,  5 SR and output as sound from the speakers  10 SL,  10 SR. Processing in the sound image processing circuits  4 SL,  4 SR, amplification in the amplifiers  5 SW-b to  5 SR and the like are carried out based on a predetermined operation and control of a control unit  3 . 
     Next, an example of position where the subwoofer box  11  is attached is described with reference to  FIG. 6 .  FIG. 6  is a side view of the AV rack  100 . As shown in  FIG. 6 , a television receiver  60  is arranged on the top board portion  30  of the AV rack  100  in this example. Here, in  FIG. 6 , a member covering the side surface of the AV rack  100  is not illustrated in order to show the inside of the AV rack  100 . 
     As shown in  FIG. 6 , the subwoofer box  11  is arranged at the rear side when viewed from a user e 1 . The subwoofer box  11  is arranged at the rear side so that the subwoofer box  11  may be less noticeable for the user e 1 . The position in the depth direction where the subwoofer box  11  is arranged is calculated based on the height of the user&#39;s eyes, the distance to the user and the like. 
     For example, in the case where the height of the user&#39;s eyes is 90 cm that corresponds to the sum of the height of the AV rack  100  and half the height of the television receiver  60  and then the distance between the user e 1  and the television receiver  60  is 2 m, values described below can be calculated. Specifically, an angle θ formed when the user e 1  looks down at the lower part of the shelf board portion  40  can be calculated as about 42° by using the distance (here, 18 cm) between the center position of the television receiver  60  and the front surface of the AV rack  100  and the height (15 cm in this example) of the shelf board portion  40  from the floor level. Further, the distance X reached with the user&#39;s eyes can be calculated using such values (in the case where the leg portion  20   a  has the thickness of 5 cm in the depth direction, the distance X is about 11 cm). If the subwoofer box  11  is placed in a position having more distance to the front surface than the calculated distance X, the subwoofer box  11  is not shown to the user e 1 . 
     As described above, since the subwoofer box  11  is provided under the shelf board portion  40  in the position having a predetermined distance in the depth direction, the subwoofer box  11  may be not readily shown to the user e 1 . Accordingly, design limits for the AV rack  100  caused by providing a subwoofer may be eliminated. 
     Further, the subwoofer units  10 SW- a ,  10 SW- b  are arranged on the front surface facing the user. Therefore, the sound from the subwoofer units  10 SW- a ,  10 SW- b  is directly output in the direction of the user, so that the quality thereof can be maintained. 
     Further, the respective subwoofer units  10 SW- a ,  10 SW- b  are arranged in the position having the equal distance from the center of the AV rack  100 . Hence, out of the frequency band of 40 Hz to 200 Hz output from the subwoofer units  10 SW- a ,  10 SW- b  according to the embodiment, sound in the frequency band of 150 Hz or more, which may have the directivity, can be output in a fine balance. 
     In the above-described embodiment, a blind screen  21  may be provided right under the front surface of the shelf board portion  40  as shown in  FIG. 7  so that the user e 1  may not notice the subwoofer box  11 . With such structure, the subwoofer box  11  may be less noticeable for the user e 1 . 
     Next, an example of joining of the subwoofer box  11  to the shelf board portion  40  will be described with reference to  FIG. 8 . As shown in  FIG. 8 , a reinforcement member  41  as a structure to increase the strength of the AV rack  100  is provided under the shelf board portion  40 . The subwoofer box  11  is suspended and held using subwoofer holding portions  42   a ,  42   b  attached to the reinforcement member  41 . 
     As described above, the subwoofer box  11  is not directly joined to the leg portions  20   a ,  20   b . Therefore, vibrations generated at the subwoofer unit in the subwoofer box  11  may be suppressed so as not to reach to an audio apparatus or the like arranged on the AV rack  100  or stored therein. 
     Alternatively, as shown in  FIG. 9 , subwoofer holding portions  42   a ′,  42   b ′ alone may hold the subwoofer box  11 . According to this embodiment, the subwoofer box  11  is supported by the subwoofer holding portions  42   a ′,  42   b ′ fixed to the leg portions  20   a ,  20   b  respectively. Basically, a speaker box such as the subwoofer box  11  is a structure having the strength, so that the subwoofer box  11  and the subwoofer holding portions  42   a ′,  42   b ′ may serve as a part of the structure of the AV rack  100 . Accordingly, there may be no need to provide a structure to reinforce the AV rack  100  separately and therefore manufacturing costs for the AV rack  100  may be reduced. 
     In the case of using such strength inherent to a speaker box such as the subwoofer box  11  so that the speaker box serves as a part of the structure of the AV rack  100 , other members than the subwoofer box  11  may be arranged under the shelf board portion  40 . Specifically, another speaker box storing the center speaker or the like may be arranged. 
     It should be noted that the subwoofer units  10 SW- a ,  10 SW- b  are arranged on the front surface according to the above-described embodiment. However, as shown in  FIG. 10 , the subwoofer units  10 SW-a,  10 SW-b may be arranged on the side surfaces, facing in opposite directions. In this case, reflecting plates  16   a ,  16   b  are provided on the side surfaces of the leg portions  20   a ,  20   b  so that the sound output from the subwoofer units  10 SW- a ,  10 SW- b  can be reflected in the direction of the user. Further, in this case, if bass reflex ports  15   a ,  15   b  are arranged on the front surface, sound in the low frequency band can be output in the direction of the user. 
     In addition, according to the above-described embodiment, other speaker units than the subwoofer units are incorporated in the top board portion  30 . However, an embodiment according to the present invention may be applied to an AV rack  100  including the subwoofer alone. The structure of an AV rack in this case will be described with reference to  FIG. 11 . 
     Similar to the heretofore described AV rack  100  according to the embodiment, an AV rack  100 ′ shown in  FIG. 11  includes a top board portion  30 ′ on which a television receiver or the like is arranged and which is held by leg portions  20   a ′,  20   b ′ at both ends thereof. A subwoofer box  11 ′ including subwoofer units  10 SW- a ′,  10 SW- b ′ is provided under a shelf board portion  40 ′ extending between the leg portions  20   a ′,  20   b′.    
     Accordingly, the AV rack  100 ′ shown in  FIG. 11  only includes the subwoofer box  11 ′. According to the AV rack  100 ′, the sound in other frequency band than a reproduction frequency band of the subwoofer units  10 SW- a ′,  10 SW- b ′ is output from speakers of other apparatus such as a television receiver (not shown in  FIG. 11 ) provided on the AV rack  100 ′. 
     Further, in the case where surround sound of 5.1 or more channels may not be reproduced, a subwoofer is added as an independent unit to expand the range of sound. In this case, a comparatively large subwoofer box may need to be arranged in an appropriate position in the room. If the AV rack  100 ′ incorporating the subwoofer box  11 ′ as shown in  FIG. 11  is used, sound of a low frequency band that is not reproduced using a typical speaker unit can be reproduced. 
     Further, as shown in  FIGS. 8 and 9 , according to the above-described embodiment of the present invention, the subwoofer box  11  is fixed to the reinforcement member  41  and the leg portions  20   a ,  20   b  using the subwoofer holding portions  42   a ,  42   b . However, the subwoofer box  11  may be directly fixed to the shelf board portion  40  using the subwoofer holding portions  42   a ,  42   b.    
     Further, according to the above-described embodiment of the present invention, two holding portions to hold the subwoofer box  11  are provided on the right and left respectively. However, the number of holding portions is not limited thereto. The subwoofer box  11  may be held using three or more portions. 
     Furthermore, according to the above-described embodiment of the present invention, the front surface of the speaker unit including the subwoofer is exposed. However, a speaker cloth may be provided to cover the front surface. 
     Moreover, the leg portions  20   a ,  20   b  may be used as a pressure board. 
     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.