Patent Publication Number: US-2016227323-A1

Title: Receiver Having Diaphragm with Improved Rigidity

Description:
PRIORITY CLAIM 
     The present application claims priority to Korean Patent Application No. 10-2015-0014938 filed on 30 Jan. 2015, the content of said application incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present invention relates to a receiver, and more particularly, to a receiver having diaphragm including a side diaphragm and a central diaphragm and having a central portion with improved rigidity. 
     BACKGROUND 
     A receiver is a device transferring an audio signal to a user&#39;s ear that comes closer thereto, unlike a speaker transferring a sound at a predetermined distance. In general, a receiver is positioned in a receiving part of a mobile phone to generate a telephone sound, or the like. 
     The receiver is so small that is difficult to manufacture and has a high defect rate, compared with a microspeaker generating sound when DMB of a mobile phone or an MP3 file is played. Also, since the receiver is a subminiature device, a diaphragm thereof is required to be small and thin; however, a thin diaphragm has shortcomings in that rigidity of a central portion thereof is weak. 
       FIGS. 1 through 3  are views illustrating a conventional receiver. 
     In the conventional receiver, a magnetic circuit including a yoke  21 , an inner magnet  22 , an outer ring magnet  23 , an inner top plate  24 , and an outer ring top plate  25  is installed within a frame  10 , and a vibration unit including a voice coil  30  having a lower end positioned in an air gap between the inner magnet  22  and the outer ring magnet  23  and a diaphragm  40 , to which the voice coil  30  is attached, vibrating together with the voice coil  30  to generate sound, is mounted on the frame. Also, the related receiver includes a protector engaged with the frame  10  and positioned on the diaphragm  40  to protect the vibration unit and the magnetic circuit. 
     Referring to  FIGS. 2 and 3 , the diaphragm  40  provided in the conventional receiver includes an outer circumferential portion  41  mounted on the frame  10 , a central portion  43  formed to be spaced apart from the outer circumferential portion  41 , and a dome portion  42  elastically connecting the outer circumferential portion  41  and the central portion  43 . The dome portion  42  may protrude in an upward direction, that is, in a direction toward the protector  50 , or protrude in a downward direction, that is, in a direction toward the yoke  21 . In the conventional illustrated in  FIGS. 2 and 3 , the dome portion  42  has a reversed dome shape protruding in a downward direction. The dome portion  42  includes a plurality of protruding ribs  44  increasing elastic force and rigidity to support the central portion  43 . The central portion  43  includes a plurality of protrusions  45  increasing rigidity of the central portion  43  to increase a bandwidth of the receiver. The protrusions  44  may protrude upwardly or downwardly. In the conventional illustrated in  FIGS. 2 and 3 , an example in which the protrusions  44  protrude upwardly is illustrated. 
     The conventional receiver illustrated in  FIGS. 1 through 3  has the protrusions  45  to increase rigidity of the central portion thereof, but the rigidity is still insufficient and the bandwidth is not wide yet. 
     SUMMARY 
     An object of the present invention is to provide a receiver with rigidity improved to widen a bandwidth, as a subminiature receiver. 
     According to an aspect of the present invention for achieving the above objects, there is provided a receiver having a diaphragm with improved rigidity, including: a frame; a yoke coupled to the frame and forming a bottom surface; a magnet coupled to the yoke; a voice coil provided such that a lower end thereof is positioned in an air gap of the magnet, and vibrated up and down by mutual electromagnetic force as a current is applied thereto; a side diaphragm allowing the voice coil to be attached to a lower surface thereof; a central diaphragm attached to the center of the side diaphragm; and a protector coupled to the frame to cover the frame, wherein the side diaphragm and the central diaphragm have protrusions protruding in mutually opposite directions, and a space is formed between the protrusions of the side diaphragm and the protrusions of the central diaphragm. 
     The protrusions formed on the central diaphragm may include a first protrusion formed in a first direction and a second protrusion formed to traverse the first protrusion and protruding further than the first protrusion. 
     The side diaphragm may include an outer circumferential portion mounted on the frame, a central portion disposed to be spaced apart from the outer circumferential portion by a predetermined interval and allowing the central diaphragm to be attached thereto, and a dome portion protruding upwardly or downwardly to elastically connect the outer circumferential portion and the central portion. 
     The central diaphragm may be attached to an upper surface of the side diaphragm, and the protrusions of the side diaphragm may protrude downwardly, and the protrusions of the central diaphragm may protrude upwardly. 
     The central diaphragm may be attached to a lower surface of the side diaphragm, and the protrusions of the side diaphragm may protrude upwardly, and the protrusions of the central diaphragm may protrude downwardly. 
     In the receiver according to an embodiment of the present invention, since the central diaphragm is additionally attached to the central portion of the side diaphragm, rigidity of the central portion of the diaphragm may be improved. 
     Also, in the receiver according to an embodiment of the present invention, since the side diaphragm and the central diaphragm have protrusions, separately, rigidity of the central portion of the diaphragm may be further improved. 
     Also, in the receiver according to an embodiment of the present invention, since a space is formed between the protrusions provided in the side diaphragm and the central diaphragm to form an air layer, rigidity of the central portion of the diaphragm may be further improved. 
     Those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of a conventional receiver; 
         FIG. 2  is a view illustrating a diaphragm provided in the conventional receiver of  FIG. 1 ; 
         FIG. 3  is a cross-sectional view taken along line A-A in  FIG. 2 ; 
         FIG. 4  is a cross-sectional view of a receiver in which a central portion of a diaphragm has improved rigidity according to an embodiment of the present invention; 
         FIG. 5  is a view illustrating a diaphragm of a receiver in which a central portion of a diaphragm has improved rigidity according to an embodiment of the present invention; and 
         FIG. 6  is a cross-sectional view illustrating a diaphragm of a receiver in which a central portion of a diaphragm has improved rigidity according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. 
       FIG. 4  is a cross-sectional view of a receiver in which a central portion of a diaphragm has improved rigidity according to an embodiment of the present invention. 
     A receiver in which a central portion of a diaphragm has improved rigidity according to an embodiment of the present invention includes a frame  100 , a magnetic circuit unit, a vibration unit, and a protector  500 , like the conventional receiver. 
     The magnetic circuit unit includes a yoke  210  coupled to a bottom of the frame  100  to form a bottom surface of the receiver, an inner magnet  220  attached to the yoke  210  and positioned within the frame, an outer ring magnet  230  attached to the yoke  210 , positioned within the frame  100 , and positioned to be spaced apart from the inner magnet  220  by a predetermined interval, an inner top plate  240  attached to an upper surface of the inner magnet  220  to assist formation of a magnetic field, and an outer ring top plate  250  attached to an upper surface of the outer ring magnet  230  to assist formation of a magnetic field. 
     The vibration unit includes a voice coil  300  and a diaphragm, and the diaphragm includes a side diaphragm  410  and a central diaphragm  420 . A lower end of the voice coil  300  is positioned in an air gap between the inner magnet  220  and the outer ring magnet  230 , and vibrates up and down according to mutual electromagnetic force when a signal is applied to the voice coil  300 . An outer circumferential portion  411  (see  FIG. 2 ) of the side diaphragm  410  is mounted on the frame  100 , and the voice coil  300  is attached to a lower surface of the side diaphragm  410 . Thus, when the voice coil  300  vibrates, the side diaphragm  410  vibrates together to generate sound. The central diaphragm  420  is attached to a central portion  413  (pleases refer to  FIG. 2 ) of the side diaphragm  410  to improve rigidity of the central portion of the diaphragm. 
       FIG. 5  is a view illustrating a diaphragm of a receiver in which a central portion of a diaphragm has improved rigidity according to an embodiment of the present invention, and  FIG. 6  is a cross-sectional view illustrating a diaphragm of a receiver in which a central portion of a diaphragm has improved rigidity according to an embodiment of the present invention. 
     The side diaphragm  410  includes an outer circumferential portion  411  mounted on the frame  100  (see  FIG. 4 ), a central portion  413  formed to be spaced apart from the outer circumferential portion  411  and allowing the voice coil  300  (see  FIG. 4 ) and the central diaphragm  420  to be attached thereto, and a dome portion  412  protruding downwardly to elastically connect the outer circumferential portion  411  and the central portion  413 . In the embodiment illustrated in  FIGS. 5 and 6 , the dome portion  412  protrudes downwardly, but a dome portion protruding upwardly may also be employed. 
     The dome portion  412  includes a plurality of protrusion ribs  414  for increasing rigidity of the dome portion  412  so that the central portion  413  may not sag due to weight of the voice coil  300  and the central diaphragm  420  attached thereto. The protrusion ribs  414  are generally formed at the corner portions, but may also be formed in other portions. 
     The central portion  413  of the side diaphragm  410  has a plurality of protrusions  415  for increasing rigidity of the central portion  413  to widen a range generated by the receiver. A plurality of protrusions  415  are provided to be parallel to a shorter side of the side diaphragm  410  having a rectangular shape. Here, when the side diaphragm  410  has a rectangular shape, it may also include a shape in which the corners of the rectangular shape are rounded or chamfered. The plurality of protrusions  415  may also be disposed to be parallel to a longer side of the side diaphragm  410  or may have any other shape such as a grid shape. 
     The central diaphragm  420  has an attachment surface  421  attached to the central portion  413  of the side diaphragm  410  and a plurality of first protrusions  422  protruding from the attachment surface  421 . The first protrusions  422  and the protrusions  415  of the side diaphragm  410  have shapes corresponding to each other, and protrude in the mutually opposite directions such that a space may be formed therebetween. According to the embodiment illustrated in  FIGS. 5 and 6 , the central diaphragm  420  is attached to an upper surface of the side diaphragm  410 , the protrusions  415  protrude downwardly, and the first protrusions  422  protrude upwardly. However, the central diaphragm  420  may be attached to a lower surface of the side diaphragm  410 , the protrusions  415  may protrude upwardly, and the first protrusions  422  may protrude downwardly. In this manner, since a space allowing an air layer to be formed therein is provided by the protrusions  415  and the first protrusions  422 , rigidity of the central portion of the diaphragm may be further improved to help increase a bandwidth of the receiver. 
     The central diaphragm  420  may further include a second protrusion  423 , in addition to the first protrusions  422 . The second protrusion  423  is provided to traverse the plurality of first protrusions  422 , and a protruding height of the second protrusion  423  is higher than that of the first protrusions  422 . However, the protruding height of the second protrusion  423  may be equal to or lower than that of the first protrusions  422 . Since the second protrusion  423  is additionally formed, rigidity of the central portion of the diaphragm may be further improved. 
     As used herein, the terms “having”, “containing”, “including”, “comprising” and the like are open-ended terms that indicate the presence of stated elements or features, but do not preclude additional elements or features. The article and “the” are intended to include the plural as well as the singular, unless the context clearly indicates otherwise. 
     With the above range of variations and applications in mind, it should be understood that the present invention is not limited by the foregoing description, nor is it limited by the accompanying drawings. Instead, the present invention is limited only by the following claims and their legal equivalents.