Patent Publication Number: US-9854353-B2

Title: Omni-directional ported speaker

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is related to and claims the benefit of Chinese Patent Application Number 201510284222.5 filed on 28 May 2015, the contents of which are herein incorporated by reference in their entirety. 
     FIELD OF THE INVENTION 
     The present invention relates to speaker structure and more particularly, to an omni-directional ported speaker, which has multiple ducts for air flow. 
     BACKGROUND OF THE INVENTION 
     A conventional driver of a speaker is operated by causing a voice coil of the speaker to vibrate, and move a cone of the speaker to reproduce sound pressure waves to allow a user to hear the sound. In order to achieve a better effect, the driver is mounted in a cabinet for preventing acoustic short circuit by separating a front and rear sound field of the driver. 
     During the vibration of the voice coil, if the voice coil moves forward, the density of the air in front of the driver is increased, and air density behind the driver is reduced. If there is no block therebetween, the air with greater density moves toward the air with less density, and this is called acoustic short circuit. Acoustic short circuit relates to the frequency, in particular appears in low frequencies. Therefore, a well-designed cabinet can improve the effect of low frequencies. 
     Referring to  FIG. 1 , there are two kinds of speaker boxes differentiated by the structures therein. One is enclosure speaker, and the other is ported speaker. The ported speaker can produce much lower frequencies than the enclosure speaker. Typical ported speaker has an opening  4  and a duct  6  for connecting the driver  2 . 
     When a ported speaker operates, the air flows in the duct quickly. However, the opening of the ported speaker is usually of insufficient size, which causes frictional loss during operation and results in noise of the ported speaker. 
     Inasmuch as aforementioned, an omni-directional ported speaker is herein disclosed in the present invention to resolve the drawbacks of the prior art. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention provides an omni-directional ported speaker which can disperse the air in a single duct to eliminate the noise caused by the air friction in the duct. 
     The invention further provides a column-like structure, e.g. a pillar. Therefore, it is easy to connect to a driver of a speaker. 
     The invention additionally provides an adequate space of the column-like structure. The space is not only for a driver, but also for ducts. The length of the ducts can be elongated, and better low frequency response can be achieved. 
     More particularly, the invention provides an omni-directional ported speaker having a driver. The driver has a cone diaphragm portion and a driving portion. The omni-directional ported speaker comprises a cabinet for the driver mounted therein, and the cabinet has a first opening at one end portion and a second opening at the other end portion. The cone diaphragm portion of the driver is close to the second opening. A cover member is connected to the first opening, and the cover member has a first duct and a plurality of second ducts. The first duct and each of the second ducts have two openings. One of the two openings of the first duct is coupled to one of the openings of the second ducts, and the other opening of the first duct is disposed closing to the driving portion along the direction from the first opening of the cabinet toward the second opening of the cabinet. The other openings of the second ducts are arranged in the cover member, wherein the first duct and the second ducts included a first angle, and each of the second ducts included a second angle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a vertical cross-section of a prior ported speaker. 
         FIG. 2  is a perspective view of an omni-directional ported speaker in accordance with a first embodiment of the invention. 
         FIG. 3  is a perspective view of an omni-directional ported speaker in accordance with a second embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In order to fully comprehend the objectives, features and efficacy of the present invention, a detailed description is described by the following substantial embodiments in conjunction with the accompanying drawings. The description is as below. 
     Referring to  FIG. 2 , it is a perspective view of an omni-directional ported speaker in accordance with the first embodiment of the invention. The omni-directional ported speaker  10  has a driver  2 . The driver  2  comprises a cone diaphragm portion  22  and a driving portion  24 . The driving portion  24  is acted by electric power to move the cone diaphragm portion  22  for produce sound wave. 
     The omni-directional ported speaker  10  comprises a cabinet  12  and a first cover member  14 . 
     In the first embodiment, the cabinet  12  is a pillar. That is, the cabinet  12  is substantially cylindrical in shape. In other possible embodiments, the cabinet  12  can be other shapes. The inner side of the cabinet  12  is a space  122  for disposed the driver  2 . The cabinet  12  has a first opening  124  at one end and a second opening  126  at the other end. As the driver  2  disposed in the space  122  of the cabinet  12 , the cone diaphragm portion  22  is disposed at and serves to close the second opening  126 . In particular, the driver  2  can be easily connected to the cabinet  12  because the shape of the driver  2  is circular shape in this embodiment which fits to the shape of the cabinet  12 . 
     The first cover member  14  is connected to the first opening  124 . Furthermore, the first cover member  14  and the first opening  124  can be connected in any sufficient manner such as, for example, by locking or clamping. The first cover member  14  has a first duct  142  and a plurality of second ducts  144 . In the embodiment, the numbers of the second ducts  144  are four. In other embodiments, the number of the second ducts might be even or odd numbers. 
     The first duct  142  is disposed in the center of the first cover member  14 , and has two openings  1422 ,  1424 . Besides, each of the second ducts  144  also has two openings  1442 ,  1444 . Furthermore, the second ducts  144  can have a shape of a rectangular tube, a pipe, or a square tube. The opening  1422  of the first duct  142  is coupled to the openings  1442  of the second ducts  144 . The opening  1424  of the first duct  142  is disposed proximate to the driving portion  24  and the first duct  142  is arranged along the direction from the first opening  124  of the cabinet  12  toward the second opening  126  of the cabinet  12 . That is, in this exemplary embodiment, the first duct extends axially within the pillar shaped cabinet  12 . Each of the openings  1444  of the second duct  144  are arranged on the periphery of the first cover  14  and open outward of the cabinet  12 . Besides, the side portion of the first duct  142  and the sides of the second ducts  144  delimit a first angle θ 1 , and each of the second ducts  144  delimit a second angle θ 2  with respect to an adjacent second duct. The second angle θ 2  is in accordance with a formula of 360°/A, and A is the numbers of the second ducts  144 . In the first embodiment, the first angle θ 1  is ninety degrees. Because the numbers of the second ducts  144  are four in the embodiment, the second angle θ 2  is also ninety degrees. 
     As shown in  FIG. 3  which is the perspective view of an omni-directional ported speaker in accordance with a second embodiment of the invention, the omni-directional ported speaker  10 ′ also has a cabinet  12  and first cover member  14  same as the first embodiment, however, the omni-directional ported speaker  10 ′ further comprises a second cover member  16 . 
     The second cover member  16  is connected to the second opening  126 . Here, the driver  2  has a third opening  162  for the cone diaphragm portion  22  of the driver  2  to produce sound waves. Besides, there are several holes  164  disposed on the periphery of the second cover member  16 . When the omni-directional ported speaker  10 ′ is vertically placed, the sound waves can go through the holes  164 . In the second embodiment, there are four holes  164 . 
     Moreover, the first duct  142  and the second ducts  144  can be integrally formed such that they define a single continuous structure. 
     The present invention is disclosed by the preferred embodiment in the aforementioned description; however, it is contemplated for one skilled at the art that the embodiments are applied only for an illustration of the present invention rather than are interpreted as a limitation for the scope of the present invention. It should be noted that the various substantial alternation or replacement equivalent to these embodiments shall be considered as being covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be defined by the claims.