Patent Publication Number: US-8116505-B2

Title: Speaker apparatus and display apparatus with speaker

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a speaker apparatus suitable for use in, for example, speakers for television receivers, and to a display apparatus with speaker which houses the speaker apparatus. 
     2. Description of Related Art 
     Recently, in image display apparatuses such as television receivers, the prevailing image display means are those using a flat display panel such as a liquid crystal display panel. In the display apparatuses using the flat display panel such as a liquid crystal display, a casing which forms the main body of the display apparatus is flat, and therefore, a speaker housed in the display apparatus is also required to be made flat. 
     Japanese Patent Application Publication No. JP 2006-311324 (Patent Document 1) discloses an example where speakers are incorporated into the right and left of a flat image display apparatus, respectively. Japanese Patent Application Publication No. JP 10-23582 (Patent Document 2) discloses formation of a certain degree of space at the front of a speaker unit when incorporating speakers into a casing which forms the main body of this type of apparatus. 
     SUMMARY OF THE INVENTION 
     The incorporation of the speaker apparatus into the flat image display apparatus necessitates to make the speaker apparatus thin. However, thinned the speaker apparatus is not preferable in terms of sound quality. That is, the speaker apparatus is designed such that a speaker box having a certain degree of volume is disposed on the back side of a speaker unit which includes a diaphragm and a magnetic circuit for driving the diaphragm. Echoes in the speaker box are used to efficiently output sounds from the speaker unit. Thus if the apparatus is made thin, a sufficient volume of the speaker box is difficult to be kept in designing an image display apparatus. It is therefore important to ensure good sound quality of speakers in electronic equipments such as flat image display apparatuses. 
     According to an embodiment of the present invention, it is desirable to improve the sound quality of speakers housed in electronic equipments such as flat image display apparatuses. 
     An embodiment of the present invention is applicable to a speaker apparatus arranged in a predetermined casing, or to a display apparatus with speaker which houses the speaker apparatus. The configuration thereof includes a speaker unit disposed at a predetermined position in a casing, and a speaker grill section formed with sound output holes, disposed at a position with a predetermined distance kept from the speaker unit on the front of a sound output surface locating at the position of the speaker unit of the casing. A first front air chamber is formed between the speaker unit and the speaker grill section in the casing, and separated from other sections in the casing. A second front air chamber is formed which extends from the first front air chamber on the front of the speaker unit. 
     With this configuration, the quality of sound outputted from the speaker grill may be improved by the action of the front air chamber provided in front of the speaker unit. Particularly, in an embodiment of the present invention, by the conjoint action of the first front air chamber disposed on the front of the speaker unit and the second front air chamber connected to the first front air chamber, sound may be echoed satisfactorily in a relatively large space during the time the sound outputted from the speaker unit is outputted from the speaker grill section. This enables reproduced sound to be improved effectively. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a whole configuration example of equipment according to an embodiment of the present invention; 
         FIG. 2  is a cross-sectional view taken along the line II-II in  FIG. 1 ; 
         FIG. 3  is an exploded perspective view as viewed from the front of a main section in the first embodiment of the present invention; 
         FIG. 4  is an exploded perspective view as viewed from the back of the main part in the first embodiment of the present invention; 
         FIG. 5  is a cross-sectional view of a connecting section between a speaker unit and a baffle in the first embodiment of the present invention; 
         FIG. 6  is a partial perspective view showing an example of the mounting state of the baffle in the first embodiment of the present invention; and 
         FIG. 7  is a perspective view showing an example of the baffle in the first embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     An embodiment of the present invention will be described below with reference to the accompanying drawings. 
     The present embodiment is concerned with an example applied to a television receiver as an electronic equipment. 
       FIG. 1  is a perspective view showing a whole configuration example of the television receiver. A television receiver  10  is configured as a flat display using a liquid crystal image display panel or a plasma image display panel, assuming a relatively large screen size, such as 30-inch, a 40-inch, or more. 
     In the surroundings of a display panel  11  disposed centrally of the front of the television receiver  10 , a front panel  12  is arranged such that it surround four sides of the display panel  11 . The front panel  12  is integrally formed by synthetic resin. The front panel  12  is connected to a rear cover  15 , to form a casing of the main body of the television receiver. The rear cover  15  is also integrally formed by synthetic resin. 
     A speaker grill  20  for outputting the sound from a speaker is disposed below the front panel  12 . The speaker grill  20  is of oblong and horizontally long slender shape, and has substantially the same length as that of the width of the display panel  11 . The speaker grill  20  has a plurality of tiny holes arranged at constant intervals and, through the holes the sound from the inside speaker unit is outputted. For example, the holes having a diameter of approximately 1 mm, are arranged both longitudinally and laterally at intervals of approximately 2 mm. As will be described later, a part (the central section) of the speaker grill  20  provided with the tiny holes is a section through which no sound from the speaker unit is outputted. Although the holes are constantly arranged on the surface of the speaker grill  20 , at the section, from which no sound from the speaker unit is outputted, the holes are not configured to pass through the internal surface. Since the holes are arranged constantly with substantially same interval as the width of the display panel  11  kept, the speaker grill  20  has an excellent design. 
     A speaker front decorative panel  13  has a configuration in that a resin sheet and a fabric sheet, and the like, having tiny holes are arranged such that the sound outputted from the speaker unit (not shown) disposed at the rear of the speaker front decorative panel  13  may be outputted to the exterior. 
     The decorative panel  13  is disposed below the speaker grill  20  of the television receiver  10  in the present embodiment. For example, the decorative panel  13  is shaped as a mirror, and incorporates partially a lighting section for various pilot lamps and a light receiving section of remote control signals. When the television receiver  10  is installed by placing it on television stands (not shown), legs (stands)  16  are fixed to lower sections of the television receiver  10 , as shown in  FIG. 1 . When installed to the wall, fixing of the legs  16  is not required. 
     Next, the configuration of the speaker apparatus housed in the television receiver  10  will be described with reference to  FIG. 2  and the succeeding drawings. 
       FIG. 2  is a transverse cross-sectional view taken along the line II-II in  FIG. 1 , and when viewed from the front, it shows the inside of the casing at the section where the speaker grill  20  is disposed. However, in  FIG. 2 , the vicinity around the center of the corresponding cross-section is omitted by breaking away. As shown in  FIG. 2 , the casing as the main body of the television receiver  10  is configured such that the front panel  12  with the speaker grill  20  and the rear cover  15  are connected. For connecting the front panel  12  and the rear cover  15 , screw hole portions  21   a ,  21   b ,  21   c  and  21   d  are disposed at the side of the front panel  21  with predetermined intervals kept, and screw fitting portions  17   a ,  17   b ,  17   c  and  17   d  are disposed at the side of the rear cover  15  which is opposite positions of respective hole portions. The front panel  12  and the rear cover  15  may be assembled integrally by threading screws (not shown) from the screw fitting portions  17   a ,  17   b ,  17   c  and  17   d  to the screw hole portions  21   a ,  21   b ,  21   c  and  21   d , respectively. At the time of the threading, fixing rubbers  54  and  55  are interposed between the screw fitting portions  17   a ,  17   b ,  17   c  and  17   d  and the screw hole portions  21   a ,  21   b ,  21   c  and  21   d , respectively. 
     Speaker units  50 L and  50 R are disposed at the left end and the right end, respectively, in the section of the casing where the speaker grill  20  is disposed. The left speaker unit  50 L is a speaker unit for outputting sound composed of audio signals of the left channel synchronized with images displayed on the television receiver  10 . The right speaker unit  50 R is a speaker unit for outputting sound composed of audio signals of the right channel synchronized with images displayed on the television receiver  10 . 
     The speaker units  50 L and  50 R have the same shape, namely full-range type speaker units using elliptic cone-type diaphragms, respectively. As shown in  FIG. 2 , a predetermined clearance is formed between the speaker grill  20  and the sound output surfaces of the speaker units  50 L and  50 R, respectively. In the present embodiment, the abovementioned clearance is used as a front air chamber separated from other space in the casing. 
     Specifically, a front air chamber  22  (a first front air chamber) is disposed between the sound output surface of the speaker unit  50 L and the speaker grill  20 . An extended front air chamber  23  (a second front air chamber) extending toward the center along the speaker grill  20  is connected to the front air chamber  22 . Similarly, a front air chamber  24  is disposed between the sound output surface of the speaker unit  50 R and the speaker grill  20 . An extended front air chamber  25  extending toward the center along the speaker grill  20  is connected to the front air chamber  24 . As shown in  FIG. 2 , the front air chamber  22  of the left channel, the extended front air chamber  24  of the left channel, the extended front air chamber  25  of the right channel, and the front air chamber  23  of the right channel are arranged sequentially. 
     The front air chamber  22  for the left channel and its extended front air chamber  24  are connected such that air flow therethrough, and separated from other sections in the casing. Similarly, the front air chamber  24  for the right channel and its extended front air chamber  25  are connected such that air flow therethrough, and separated from other sections in the casing. 
     Baffles  30 L and  30 R are disposed at the rear of the extended front air chambers  24  and  25 , respectively, such that they cover the back. Screw hole portions  21   e  and  21   f  shown in  FIG. 2  are screw holes for fixing the baffles  30 L and  30 R, respectively. 
     At the rear of the speaker units  50 L and  50 R, sealed spaces  26  and  27  forming a speaker box are formed in the casing. The shapes of these sealed spaces  26  and  27  included in the speaker box are determined depending on the shape of the rear cover  15 . 
     Referring to  FIGS. 3 to 7 , a description will be made of the configurations of the front air chambers  22  and  23  and the extended front air chambers  24  and  25 , which are interposed between the speaker grill  20  and the speaker units  50 L and  50 R, respectively, as well as the configuration of the peripheral thereof. In  FIG. 3  and the succeeding drawings, the configurations of the speaker unit  50 L for the left channel and the surrounding thereof are shown, with the configuration of the right channel side omitted. The right and left channels sides have the same shape and a laterally symmetrical configuration. 
       FIG. 3  is an exploded view as viewed from the front, showing the configuration in the vicinity of the speaker unit  50 L and the speaker grill  20 .  FIG. 4  is an exploded view as viewed from the back. As shown in these drawings, the speaker unit  50 L has an elliptic diaphragm  51  and a magnetic circuit  52  for driving the diaphragm  51 , and a metal frame  53  is integrally mounted to the outer peripheral section of the speaker unit. The frame  53  has left and right extended sections  53   a  and  53   b , and fixing rubbers  54  and  55  are fit to the extended section  53   a  and  53   b , respectively. Holes  54   a  and  55   a  for threading are disposed at the center of the fixing rubbers  54  and  55 , respectively. Holes corresponding to the respective holes  54   a  and  55   a  are also disposed at the frame  53  side. A rectangular seal member  56  is stuck to the outer peripheral section of the diaphragm  51  of the frame  53 . Specifically, the seal member  56  is formed of an elastic resin member such as urethane resin, namely a band-shaped member that has a several mm in width and thickness, is provided such that it surrounds a rectangular periphery of the diaphragm  51 . 
     As shown in  FIG. 4 , the speaker unit  50 L is secured by fitting the fixing rubbers  54  and  55  of the speaker unit  50 L to the screw hole portions  21   a  and  21   b  at the side of the front panel  12 , and then threading them from their respective backs. Side sections  41 ,  42 ,  43  and  44  are integrally formed, by resin molding, with the front panel  12  on the front side corresponding to the position where the speaker unit  50 L is fixed. 
     The section surrounded by the side sections  41 ,  42 ,  43  and  44  corresponds to a speaker grill internal surface  20   a , through which the holes provided as the speaker grill are passed. The spaces surrounded by the side sections  41 ,  42 ,  43  and  44  are the front air chamber  22  and the extended front air chamber  23 . As shown in  FIGS. 3 and 4 , the speaker unit  50 L is disposed in the front air chamber  22 , and the baffle  30 L is disposed in the extended front air chamber  23 . 
     The baffle  30 L is a rectangular plate-shape member formed by resin molding, and has holes  32  and  33  for threading. A seal member  34  is stuck to the edge on the surface side of the baffle  30 L (the side attached to the front panel  12 ). The seal member  34  is also formed as a band-shaped member by using an elastic resin member such as urethane resin, which is about a several mm in both width and thickness. 
     Although the seal member  34  is shown as a separated member in  FIGS. 3 and 4 , it is stuck as shown in  FIG. 7 , and then attached to the front panel  12 . That is, as shown in  FIG. 3 , the seal member  34  is disposed at three side edges  30   a ,  30   b  and  30   c  on the surface side of the oblong and rectangular baffle  30 L, and the seal member  34  is not disposed at a rest side edge  30   d . End portions  34   a  and  34   b  of the seal member  34  are disposed such that it is folded back against the back side of the edge  30   d . A middle section  34   c  of the seal member  34  is disposed at the edge  30   c  facing to the edge  30   d . A double face adhesive tape or adhesive is used to stick the seal member  34  to the baffle  30 L. 
     A description will next be made of a state in which the speaker unit  50 L and the baffle  30 L thus configured is mounted on the front panel  12 . 
     By fixing the speaker unit  50 L and the baffle  30 L to the vicinity of the speaker grill internal surface  20   a  on the back of the front panel  12 , the front air chamber  22  and the extended front air chamber  23  are formed between the speaker grill internal surface  20   a  and the speaker unit  50 L and the baffle  30 L, respectively. The front air chamber  22  and the extended front air chamber  23  are arranged in series and become conductive with the exterior only through the sound output holes provided in the speaker grill internal surface  20   a , in the sealed spaced blocked by the surroundings in the casing. 
     For forming the front air chamber  22  and the extended front air chamber  23  as the sealed space, wall sections  41 ,  42 ,  43  and  44  are arranged around the speaker grill internal surface  20   a . As shown in  FIG. 4 , mounting of the speaker unit  50 L enables that parts of the tip faces  41   a  and  42   a  of the upper and lower wall sections  41  and  42 , and a tip face  43   a  of the wall section  43  adjacent to one end (the right end in  FIG. 4 ) are contacted with the seal member  56  secured to the frame  53  of the speaker unit  50 L. Shoulder portions  41   b  and  42   b  are interposed in the tip faces  41   a  and  42   b , respectively. 
     Mounting the baffle  30 L enables that the rest portions of the tip faces  41   a  and  42   a  of the upper and lower wall sections  41  and  42 , and the tip face  44   a  of the wall section  44  adjacent to the center are contacted with the seal member  34  secured to the baffle  30 L. Further, the edge  30   d  ( FIG. 3 ) of the baffle  30 L is contacted with the seal member  56  located on the side of the speaker unit  50 L. 
       FIG. 5  is a cross-sectional view of the assembled state of a connecting portion between the speaker unit  50 L and the baffle  30 L. The speaker unit  50 L and the baffle  30 L may be secured by threading a screw  61  into a common screw hole portion  21   b . At the time of mounting, the hole  33  for threading the baffle  30 L is set to be the front side (the lower side in  FIG. 5 ), and the extended portion  53   b  of the frame  53  of the speaker unit  50 L is arranged at the rear side such that it overlaps the front side (the upper side in  FIG. 5 ). At this time, the section folded back against the rear side of the end portions  34   a  and  34   b  of the seal member  34  located on the baffle  30 L makes contact with the seal member  56  located on the speaker unit  50 L, and abuts against the tip faces  41   a  and  42   b  of the wall sections  41  and  42 , and shoulder portions  41   b  and  42   b , respectively. This enables sealed-up connection between the baffle  30 L and the speaker unit  50 L. In the state of not being threaded by the screw  61  as shown in  FIG. 5 , the baffle  30 L and the speaker unit  50 L are slightly lifted from their respective normal positions due to the thickness of the seal member  34  of the baffle  30 L and the thickness of the seal member  56  of the speaker unit  50 L. Threading for securing by the screw  61  enables deformation of the seal members  34  and  56 , such that the baffle  30 L and the speaker unit  50 L are positioned at their normal positions to be connected in sealed-up manner. 
       FIG. 6  shows a state where the speaker unit  50 L and the baffle  30 L are mounted to the internal surface of the speaker grill  20  of the front panel  12 . The speaker unit  50 L and the baffle  30 L are arranged such that they cover the respective wall sections  41  to  44 . The clearance between the speaker unit  50 L and the baffle  30 L is absorbed by the shoulder portions  41   b  and  42   b  of the wall sections  41  and  42  as shown in  FIG. 4 . 
     Thus, when the speaker unit  50 L and the baffle  30 L are mounted on the back of the front panel  12 , they are connected with the wall sections  41 ,  42 ,  43  and  44  in a sealed-up manner with the seal members  34  and  56  in between. Therefore, the front air chamber  22  and the extended front air chamber  23  can be kept as a sealed space from other space in the casing. 
     Under the configuration, the presence of the front air chamber  22  and the extended front air chamber  23  enable the sound outputted from the speaker unit  53 L to be echoed in the space within the front air chamber  22  and the extended front air chamber  23 , whereby the sound outputted from the speaker grill  20  on the front side may have excellent sound characteristics. Particularly in the present embodiment, the coexistence of the front air chamber  22  and the extended front air chamber  23  connected thereto on the front of the speaker unit  50 L may allow a large space kept as the front air chamber to improve sound quality. Additionally, owing to the tiny sound output holes provided on the speaker grill  20  on the front side of the extended front air chamber  23 , both of the front air chambers  22  and  23  perform the sound output to the front side, thus enables sound output from a large widthwise range. This enables sound output in accordance with the mounting state of the display panel  11  ( FIG. 1 ). 
     Similarly, by the conjoint action of the front air chamber  24  and the extended front air chamber  25 , the sound output from the speaker unit  50 R on the right channel side allows excellent sound output. 
     By virtue of the excellent sound output performance, the speaker apparatus having excellent sound quality may be incorporated into the casing of the television receiver using the flat display panel. 
     Further, as shown in  FIG. 2  or the like, in accordance with the present embodiment, the front air chambers  22  and  24 , each housing the speaker unit, are disposed at the positions relatively adjacent to the left and right ends of the casing included in the television receiver, respectively, and the extended front air chambers  23  and  25  are disposed more adjacent to the center compared with the front air chambers  22  and  24 , respectively. These enable separate arrangement of the speaker units  50 L and  50 R of the left and right channels. Therefore, by the conjoint action of the extended front air chambers  23  and  25 , the sound quality may be improved while ensuring separation of the left and right channels. This permits excellent performance as a speaker for display apparatuses such as television receivers. 
     Although in the foregoing embodiment the extended front air chambers  23  and  25  are arranged at the positions adjacent to the center, from the left and right front air chambers  22  and  24  positioned in front of the speaker unit, these extended front air chambers may be arranged outside of the left and right front air chambers  22  and  24  positioned in front of the speaker unit. Alternatively, for the purposes of further increasing the capacity of the front air chamber, other extended front air chambers may be further disposed outside of the left and right front air chambers  22  and  24 , in addition to the extended front air chambers  23  and  25  positioned adjacent to the center as shown in  FIG. 2  or the like. 
     Although the foregoing embodiment employs, as a speaker grill, the grill section having the tiny holes formed in series by resin molding, but other speaker grill may be employed. For example, speaker grills having various configurations are applicable, such as a speaker grill formed by sticking a fabric-like member called saran-net etc to the front, a speaker grill formed by sticking a resin sheet with tiny holes provided, or a metal mesh speaker grill. It is however necessary to properly select the shape and the material of the speaker grill because when the aperture area (the size of holes etc) of the speaker grill section is too large, the front air chamber behind the speaker grill section may not function well in terms of sound characteristics. 
     Although in the embodiment, the speakers are arranged below the display panel forming the television receiver, the left channel speaker may be arranged lengthwise along the left side of the display panel, and the right channel speaker may be arranged lengthwise along a right side of the display panel. 
     Although the equipment described in the foregoing embodiment is applied to the speaker apparatus housed in the image display apparatus configured as a television receiver, it may be applied to a speaker apparatus housed in a casing that forms other display apparatus. Alternatively, the equipment is applicable to various electronic equipments where the speaker apparatus is housed in a casing other than that of the display apparatus. 
     According to an embodiment of the present invention, by the conjoint action of the first front air chamber disposed on the front of the speaker unit and the second front air chamber connected to the first front air chamber, sound may be echoed satisfactorily in a relatively large space during the time the sound outputted from the speaker unit is outputted from the speaker grill section. This enables reproduced sound to be improved effectively. 
     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. 
     The present document contains subject matter related to Japanese Patent Application No. 2006-356828 filed in the Japanese Patent Office on Dec. 29, 2006, the entire content of which being incorporated herein by reference.