Patent Publication Number: US-8538046-B2

Title: Speaker set and electronic device incorporating the same

Description:
BACKGROUND 
     1. Technical Field 
     The disclosure generally relates to speaker sets, and particularly to a speaker set used in an electronic device. 
     2. Description of Related Art 
     With the continuing development of audio and sound technology, speaker sets have been widely used in electronic devices such as mobile phones, computers, televisions and other devices providing audio capabilities. 
     Nowadays, small sized electronic devices are very popular. In such electronic devices, the shape, location and bulk of speaker sets are limited to some extent. Areas around speakers in the speaker sets are commonly cluttered with other components of the electronic device. It is well known that a high frequency range of sound output by speakers has a sensitive directionality. In other words, the high frequency range of sound is particularly susceptible to attenuation when the area in front of a speaker is even partially blocked by components. This results in increased distortion of the sound, and the quality of the sound output by the speaker set is reduced. Therefore, the design of speaker sets is limited not only by the small confines available to accommodate the speakers themselves, but also by the lack of free space around such confines. It is problematic to provide speaker sets that provide high quality output sound. 
     What is needed, therefore, is a speaker set and an electronic device incorporating the speaker set which can overcome the described limitations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the present speaker set and electronic device incorporating the speaker set can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present speaker set and electronic device incorporating the speaker set. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is a schematic view of an electronic device incorporating first and second speaker sets in accordance with a first embodiment of the disclosure. 
         FIG. 2  is an enlarged, isometric view of the first speaker set of  FIG. 1 . 
         FIG. 3  is a top plan view of the first speaker set of  FIG. 2 . 
         FIG. 4  is an exploded view of the first speaker set of  FIG. 2 . 
         FIG. 5  is similar to  FIG. 4 , but viewed from another aspect. 
         FIG. 6  is a diagram of a frequency dividing circuit of the first speaker set of  FIG. 2 . 
         FIG. 7  is similar to  FIG. 5 , but showing the first speaker set partly assembled, with a bottom cover and a sound cover of the first speaker set still not assembled. 
         FIG. 8  is an enlarged, isometric view of the second speaker set of  FIG. 1 . 
         FIG. 9  is a graph showing a performance curve of sound output from the electronic device of  FIG. 1 . 
         FIG. 10  is a front elevational view of a speaker set in accordance with a second embodiment of the disclosure. 
         FIG. 11  is a front elevational view of a speaker set in accordance with a third embodiment of the disclosure. 
         FIG. 12  is a front elevational view of a speaker set in accordance with a fourth embodiment of the disclosure. 
         FIG. 13  is a front elevational view of a speaker set in accordance with a fifth embodiment of the disclosure. 
         FIG. 14  is a diagram of a frequency dividing circuit of the speaker set of  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , an electronic device  500  incorporating a first speaker set  100  and a second speaker set  100   a  is shown. In this embodiment, the electronic device  500  is a display device. Alternatively, the electronic device  500  can be a mobile phone, a television, and so on. The electronic device  500  includes an enclosure  50  and a screen  60  fixed on the enclosure  50 . The enclosure  50  defines a plurality of tiny through holes  51  at left and right edges of a front side (or bezel) thereof. The screen  60  is located at a middle of the enclosure  50 , and includes a glass plate  61  at a front side thereof. The speaker sets  100 ,  100   a  are received in the enclosure  50 , and are symmetrically positioned at left and right sides of the screen  60 . The speaker sets  100 ,  100   a  are generally the same as each other, albeit symmetrical to each other. 
     Referring also to  FIG. 2 , the first speaker set  100  includes a shell  10 , a pair of tweeters  20 , a pair of middle woofers  30  and a frequency dividing circuit  40  (shown in  FIG. 6 ). The shell  10  is made of plastic, and includes a top cover  11  and a bottom cover  13  joined with the top cover  11 . 
     Referring to  FIGS. 3 to 5 , both of the top and bottom covers  11 ,  13  are semi-enclosed. The top cover  11  includes a mounting wall  111 , a sidewall  113  extending vertically from an outer periphery of the mounting wall  111  to the bottom cover  13 , and a sound cover  115  attached to the mounting wall  111 . The mounting wall  111  and the sidewall  113  cooperatively define a semi-enclosed resonance chamber  117  therebetween. The mounting wall  111  includes a fixing plate  1111  at a rear end thereof, an extension plate  1112  at a front end thereof, and a connecting plate  1113  connecting the fixing plate  1111  with the extension plate  1112 . Both of the fixing plate  1111  and the extension plate  1112  are substantially rectangular and planar. The fixing plate  1111  and the extension plate  1112  have a height difference. The connecting plate  1113  extends vertically and downwardly from a front end of the fixing plate  1111  (as viewed in  FIG. 4 ), and smoothly connects to a rear end of the extension plate  1112 , whereby the mounting wall  111  forms a step shape. 
     The fixing plate  1111  defines a central line L 2  extending from front to rear. In the illustrated embodiment, the central line L 2  runs along the exact middle of the mounting wall  111 . The fixing plate  1111  defines a pair of tweet outlets  1114  and a pair of middle woof outlets  1115  therethrough. The tweet and middle woof outlets  1114 ,  1115  are arranged along the central line L 2 . All of the tweet and middle woof outlets  1114 ,  1115  are circular, and each tweet outlet  1114  has a diameter less than that of each middle woof outlet  1115 . A central point N of each middle woof outlet  1115  is located nearer to the central line L 2  of the fixing plate  1111  than a central point M of each tweet outlet  1114 . In the illustrated embodiments, the central point N of each middle woof outlet  1115  is located on the central line L 2  of the fixing plate  1111 . The pair of tweeters  20  are respectively mounted in the pair of tweet outlets  1114 , and the pair of middle woofers  30  are respectively mounted in the pair of middle woof outlets  1115 . The tweet outlets  1114  are located at a rear end of the fixing plate  1111 , adjacent to a corresponding long side of the fixing plate  1111 . The middle woof outlets  1115  are located at a middle of a front end of the fixing plate  1111 , adjacent to the connecting plate  1113 . A line L 1  is defined through the central point M of any one of the tweet outlets  1114  and the central point N of any one of the middle woof outlets  1115 . The line L 1  and the central line L 2  of the fixing plate  1114  define an acute angle therebetween. 
     As shown in  FIG. 3 , in this embodiment, the tweet outlets  1114  are adjacent to each other, and the central points M of the tweet outlets  1114  are located at a left side of the central line L 2  of the fixing plate  1114 . The middle woof outlets  1115  are also adjacent to each other, and the central line L 2  of the fixing plate  1111  extends through the central points N of the middle woof outlets  1115 . A line L 3  is defined through the central points M of the tweet outlets  1114 . The line L 3  is parallel to the central line L 2 . 
     The fixing plate  1111  has a pair of rings  1116  extending vertically out toward the resonance chamber  117 . The rings  1116  are disposed around the middle woof outlets  1115 , respectively, so as to mount the middle woofers  30  thereat conveniently. A washer  1117  is disposed on an outer surface of the fixing plate  1111 , around the tweet outlets  1114 . The washer  1117  is made of elastic material, such as Ethylene Vinyl Acetate (EVA), and so on. The washer  1117  not only prevents sound leakage, but also reduces mechanical vibration between the speaker set  100  and the electronic device  500  incorporating the speaker set  100 . The fixing plate  1111  has an annular outer wall  1118  extending vertically out toward the resonance chamber  117 . The outer wall  1118  is disposed around the tweet outlets  1114 . The outer wall  1118  defines a wire groove  1119  therein, so that wires (not shown) of the tweeters  20  can pass through the outer wall  1118 . 
     A plurality of clapboards  1121  extend vertically from an inner surface of the extension plate  1112  toward the bottom cover  30 . The clapboards  1121  are covered by a sheet  1122 . The sheet  1122  forms a plurality of staggered ribs  1123  thereon, to improve the rigidity thereof. The sheet  1122 , the clapboards  1121 , the extension plate  1112  and the sidewall  113  neighboring the extension plate  1112  cooperatively define an L-shaped sound channel  1124  therebetween. The extension plate  1112  further defines a plurality of fixing holes  1125  therethrough beside the sound channel  1124 . 
     The sidewall  113  of the top cover  11  forms a step  1131  at a bottom end thereof. An inner side of the step  1131  is lower than an outer side of the step  1131 , so that the top cover  11  engages with the bottom cover  13  conveniently. The sidewall  113  defines a sound orifice  1134  at a front end of the extension plate  1112 . The sound orifice  1134  communicates with the sound channel  1124 . One portion of the sidewall  113  is sunken into the resonance chamber  117 , defining a first fixing groove  1135  at the rear end of the fixing plate  1111 . A first tab  1136  extends outwardly from the sidewall  113 , within the fixing groove  1135 . The sidewall  113  is slantwise at the connecting plate  1113  of the top cover  11 . Two second tabs  1137  extend outwardly from the sidewall  113  at two sides of the connecting plate  1113 , respectively, and a third tab  1138  extends outwardly from the sidewall  113  at the front end of the extension plate  1112 . The first, second and third tabs  1136 ,  1137 ,  1138  are adapted for fixing the speaker set  100  onto the electronic device  500 . In addition, a plurality of rubber bushings  1139  respectively enclose and cooperate with the first, second and third tabs  1136 ,  1137 ,  1138 , further reducing mechanical vibration between the speaker set  100  and the electronic device  500 . 
     The sound cover  115  is semi-enclosed, and engages with the outer wall  1118  of the fixing plate  1111  of the top cover  11  at an open end thereof to cooperatively define an enclosed receiving chamber  1151  therebetween. The tweeters  20  are received in the receiving chamber  1151 , thereby preventing sound produced by the tweeters  20  and sound produced by the middle woofers  30  from interfering with each other. The sound cover  115  further defines a tuning hole  1152  therein, which is in communication with the receiving chamber  1151  and the resonance chamber  117 . A tuning cloth  1153 , which is made of unwoven cloth, is attached over the tuning hole  1152 . The tuning cloth  1153  cooperates with the tuning hole  1152  to improve the sound quality factor and adjust the sound sharpness of the tweeters  20 , whereby high frequency sound from the tweeters  20  links smoothly with middle and low frequency sound from the middle woofers  30 . 
     The bottom cover  13  is similar to the top cover  11 , also including a mounting wall  131  and a sidewall  133  extending vertically and upwardly from an outer periphery of the mounting wall  131 . The mounting wall  131  and the sidewall  133  cooperatively define a semi-enclosed resonance chamber  137  therebetween. The mounting wall  131  is elongated and convex, and includes a fixing plate  1311  at a rear end thereof, an extension plate  1312  at a front end thereof, and a connecting plate  1313  connecting the fixing plate  1311  with the extension plate  1312 . The fixing plate  1311 , the extension plate  1312  and the connecting plate  1313  correspond to the fixing plate  1111 , the extension plate  1112  and the connecting plate  1113  of the top cover  11 , respectively. The fixing plate  1311 , the extension plate  1312  and the connecting plate  1313  are arcuate along a widthwise direction of the mounting wall  131 , and smoothly connect with each other along a lengthwise direction. 
     Two X-shaped brackets  1314  extend upwardly from the mounting wall  131 , within the resonance chamber  137 . The brackets  116  align with the middle woof outlets  1115 , and are for supporting the middle woofers  30 , respectively. 
     The extension plate  1312  has a pair of bolts  1325  extending out therefrom, corresponding to each of the fixing holes  1125 . 
     The sidewall  133  of the bottom cover  13  forms a step  1331  at a top end thereof. An inner side of the step  1331  is higher than an outer side of the step  1331 , so as to match with the step  1131  of the sidewall  113  of the top cover  11 . 
     The sidewall  133  defines a sound orifice  1334  at a front end of the extension plate  1312 . The sound orifice  1334  aligns with the sound orifice  1134  of the top cover  11 . Three portions of the sidewall  113  are sunken into the resonance chamber  137 , defining a first fixing groove  1335  at the rear end of the fixing plate  1311 , and two second fixing grooves  1337  respectively at two sides of the connecting plate  1313 . The first groove  1335  aligns with the first groove  1135  and the first tab  1136  of the top cover  11 . The second fixing grooves  1337  align with the second tabs  1137  of the top cover  11 , respectively. The sidewall  133  is also slantwise at the connecting plate  1313  of the bottom cover  13 . 
     All of the tweeters  20  and the middle woofers  30  convert electric energy into vibration to produce sound. The tweeters  20  mainly provide high frequency acoustic output. Each of the tweeters  20  includes a diaphragm  23  at a top end thereof. The diaphragm  23  has a diameter substantially equal to that of each tweet outlet  1114 . The middle woofers  30  mainly provide middle and low frequency acoustic output. Each of the middle woofers  30  has a diameter greater than that of each tweeter  20 , and also includes a diaphragm  33  at a top end thereof. The diaphragm  33  has a diameter greater than that of the diaphragm  23  of each tweeter  20 , and substantially equals to that of each middle woof outlet  1115 . 
     Referring to  FIG. 6 , the frequency dividing circuit  40  is a dual-branch frequency circuit, and thus divides sound into two frequency ranges, i.e., middle and low frequency range, and a high frequency range. The frequency dividing circuit  40  includes a capacitance C and an inductance L. A high-pass branch circuit is formed via connecting the capacitance C in series with the tweeters  20  which are connected in parallel, to filter the middle and low frequency range of the sound to be output from the tweeters  20  as much as possible. A low-pass branch circuit is formed via connecting the inductance L in series with the middle woofers  30  which are connected in series, to filter the high frequency range of the sound to be output from the middle woofers  20  as much as possible. A crossover point of the frequency dividing circuit  40  is greater than or equal to two times a lowest resonance frequency of the tweeters  20 , for gaining better high frequency signals. 
     Referring to  FIG. 7 , during assembly of the speaker set  100 , one end of each tweeter  20 , with the corresponding diaphragm  23 , is aligned with the corresponding tweet outlet  1114  of the fixing plate  1111  of the top cover  11 , and engaged with the fixing plate  1111 . One end of each middle woofer  30 , with the corresponding diaphragm  33 , is aligned with the corresponding middle woof outlet  1115  of the fixing plate  1111 , and engaged with the fixing plate  1111 . The tweeters  20  are electrically connected to the middle woofers  30  according to the configuration of the frequency dividing circuit  40 . 
     The sound cover  115  is covered on the tweeters  20 , with the tweeters  20  received in the receiving chamber  1151  of the sound cover  115 . An edge of the sound cover  115  at the open end thereof is adhered intimately to the outer wall  1118  of the fixing plate  1111  of the top cover  11 . The step  1131  of the sidewall  113  of the top cover  11  is engaged intimately with the step  1331  of the sidewall  133  of the bottom cover  13 . At this time, the resonance chamber  117  of the top cover  11  and the resonance chamber  137  of the bottom cover  13  cooperatively form a consolidated resonance chamber. The tweeters  20  and the middle woofers  30  are received in the resonance chamber, and a rear end of each middle woofer  30  closely or contactingly abuts a corresponding bracket  1314  of the bottom cover  13 . The sound orifice  1134  of the sidewall  113  of the top cover  11  and the sound orifice  1334  of the sidewall  133  of the bottom cover  13  align with each other, and further cooperatively form a consolidated sound orifice in communication with the sound channel  1124  and the outside. A plurality of screws  1225  are provided to extend through the fixing holes  1125  of the top cover  11  and be screwed into the bolts  1325  of the bottom cover  13 , respectively. Thereby, the top and bottom covers  11 ,  13  are attached together. 
     During operation of the speaker set  100 , the tweeters  20  and the middle woofers  30  produce sound forwardly and backwardly. The forward sound is directly transmitted out via the tweet and middle woof outlets  1114 ,  1115 . The backward sound enters and resonates in the resonance chamber of the speaker set  100 , and is then transmitted out via the sound channel  1124  and the sound orifice. The sound transmitted from the sound orifice and the sound transmitted from the tweet and middle woof outlets  1114 ,  1115  are combined, widening the frequency bandwidth of the sound output from the speaker set  100 . 
     Referring to  FIG. 8 , the second speaker set  100   a  is completely symmetrical to the speaker set  100 . The tweeters  20  of the second speaker set  100   a  are disposed at a right side of the central line L 2  of a fixing plate  1111   a.    
     Referring to  FIG. 1  again, the speaker sets  100 ,  100   a  are received in the enclosure  50 , and are symmetrically positioned at the left and right sides of the screen  60 . Portions of the middle woofers  30  and the middle woof outlets  1115  of each of the speaker sets  100 ,  100   a  are shaded by the glass plate  61  of the screen  60  (or other components in the electronic device  500 ), and other portions of the middle woofers  30  and the middle woof outlets  1115  are aligned with the through holes  51  of the enclosure  60 . The tweeters  20  and the tweet outlets  1114  of the speaker sets  100 ,  100   a  are located beside the glass plate  61  of the screen  60 . In other words, the tweeters  20  and the tweet outlets  1114  of the speaker sets  100 ,  100   a  are entirely aligned with the through holes  51  of the enclosure  60 , and are not shaded by the glass plate  61  of the screen  60 . 
     The middle and low frequency range of sound has a torpid directionality, and the high frequency range of sound has a sensitive directionality. Accordingly, in the present electronic device  500 , even though portions of the middle woofers  30  are shaded by the glass plate  61 , the middle and low frequency range of the sound output from the middle woofers  30  is essentially not impacted. However, since the tweeters  20  are located beside the glass plate  61 , the high frequency range of the sound output from the tweeters  20  also is not impacted. Therefore, not only is any distortion of the output sound reduced, and a sound output quality of the electronic device  500  improved; but also the overall space occupied by the electronic device  500  is reduced. 
       FIG. 9  shows a performance curve of the sound output from the electronic device  500 . As seen, the performance curve of the sound output from the electronic device  500  is relatively smooth, and the high frequency range of the sound is excellent. 
     In alternative embodiments, the locations of the tweet and middle woof outlets  1114 ,  1115  of the speaker sets  100 ,  100   a  in the electronic device  500  can be varied from the above-described conditions of the central point N of each middle woof outlet  1115  being located nearer to the central line L 2  of the fixing plate  1111 ,  1111   a  than the central point M of each tweet outlet  1114 . The embodiments described below include examples of such variations. In addition, it is to be understood that each of the speaker sets  100 ,  100   a  can be used as a sole speaker set  100  or  100   a.    
       FIG. 10  shows a speaker set  100   b  in accordance with a second embodiment of the disclosure. In this embodiment, a pair of tweet outlets  1114   b  are located between a pair of middle woof outlets  1115   b .  FIG. 11  shows a speaker set  100   c  in accordance with a third embodiment of the disclosure. In this embodiment, a pair of middle woof outlets  1115   c  are located between a pair of tweet outlets  1114   c .  FIG. 12  shows a speaker set  100   d  in accordance with a fourth embodiment of the disclosure. In this embodiment, a pair of tweet outlets  1114   d  are staggered with respect to a pair of middle woof outlets  1115   d  along the central line L 2  of a fixing plate  1111   d.    
     In alternative embodiments, the frequency dividing circuit  40  can be a multi-branch frequency circuit, and thus divides sound into a plurality of frequency ranges. In addition, a plurality of capacitances, inductances and resistances can be connected in parallel or in series in the frequency dividing circuit  40  if and as required. 
     Referring to  FIGS. 13 and 14 , a speaker set  100   e  and a frequency dividing circuit  40   e  of the speaker set  100   e  in accordance with a fifth embodiment of the disclosure are shown. 
     In this embodiment, the frequency dividing circuit  40   e  is a triple-branch frequency circuit” or “three-branch frequency circuit, and thus divides sound into three frequency ranges, i.e., a low frequency range, a middle frequency range and a high frequency range. The speaker set  100   e  includes a tweeter  20   e , a squawker  25   e  and a woofer  30   e  corresponding to the three frequency ranges, respectively. The tweeter  20   e , the squawker  25   e  and the woofer  30   e  have increasing diameters in that sequence. The tweeter  20   e  mainly provides high frequency acoustic output, the squawker  25   e  mainly provides middle frequency acoustic output, and the woofer  30   e  mainly provides low frequency acoustic output. The fixing plate  1111   e  of the speaker set  100   e  defines a tweet outlet  1114   e  in which the tweeter  20   e  is mounted, a squawk outlet  1145   e  in which the squawker  25   e  is mounted, and a woofer outlet  1115   e  in which the woofer  30   e  is mounted. The tweet, squawk and woofer outlets  1114   e ,  1145   e ,  1115   e  have increasing diameters in that sequence. The central line L 2  of the fixing plate  1111   e  extends through a central point Q of the woofer outlet  1115   e . A central point P of the squawk outlet  1145   e  is located nearer to the central line L 2  of the fixing plate  1111   e  than a central point S of the tweet outlet  1114   e.    
     A plurality of capacitances C and inductances L are connected in parallel or in series in the frequency dividing circuit  40   e . The frequency dividing circuit  40   e  includes a high-pass branch circuit electrically connecting to the tweeter  20   e , a medium-pass branch circuit electrically connected to the squawker  25   e , and a low-pass branch circuit electrically connected to the woofer  30   e . The high-pass branch circuit filters middle and low frequency ranges of the sound to be output from the tweeter  20   e  as much as possible. The medium-pass branch circuit filters high and low frequency ranges of the sound to be output from the squawker  25   e  as much as possible. The low-pass branch circuit filters high and middle frequency ranges of the sound to be output from the woofer  30   e  as much as possible. 
     It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.