Abstract:
An apparatus includes a first armature and a second armature, wherein the first armature and the second armature are coupled together in a common connection region; a coil, wherein at least a portion of the common connection region extends through the coil, the coil extending around a horizontal axis; one or more magnets; a drive rod coupled to the common connection region; and a diaphragm coupled to the drive rod; wherein electrical excitation of the coil causes the common connection region to move in a vertical direction orthogonal to the horizontal axis and not along the horizontal axis.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/093,831, filed Dec. 18, 2014, entitled REED FOR A RECEIVER AND METHOD OF METHOD OF MANUFACTURING THE SAME which is incorporated by reference in its entirety herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This application relates to receivers and, more specifically, to reeds (or armatures) used in these devices. 
       BACKGROUND OF THE INVENTION 
       [0003]    Receivers are used in many of today&#39;s electronic devices. A receiver converts electrical signals representing voice into acoustic energy that is presented for listening to a user. For example, receivers can be used in hearing instruments, personal computers, cellular phones to mention a few examples. 
         [0004]    The receiver typically includes several components. For example, these components usually include a coil, a stack, magnets, and a reed (or armature). The reed is connected to a diaphragm. Electrical current (representing sound) excites the coil, creating a magnetic field/flux together with the magnets, and this moves the reed. Since the reed is connected with the diaphragm, as the reed moves the diaphragm and displaces air, thereby creating sound. 
         [0005]    There have been some problems with these previous approaches. The desired movement of the diaphragm is in an up-down direction. Unfortunately, in many previous designs, the reed also moves in the horizontal direction. This horizontal movement creates several problems including distortion of the signal. Another problem (when the receiver is used in a hearing aid) is reducing the gain before feedback in the hearing aid due to excessive axial vibration. 
         [0006]    Previous attempts at solving this problem have been unsuccessful. This has resulted in some user dissatisfaction with these previous approaches. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    For a more complete understanding of the disclosure, reference should be made to the following detailed description and accompanying drawings wherein: 
           [0008]      FIG. 1  comprises a perspective view of a receiver module according to various embodiments of the present invention; 
           [0009]      FIG. 2  comprises a side view of the receiver of  FIG. 1  taken along line A-A according to various embodiments of the present invention; 
           [0010]      FIG. 3  comprises an end view of the receiver of  FIG. 1  and  FIG. 2  according to various embodiments of the present invention; 
           [0011]      FIG. 4  comprises an end view cross section of an armature as used in the examples of  FIG. 1 ,  FIG. 2 , and  FIG. 3  according to various embodiments of the present invention; 
           [0012]      FIG. 5  comprises a side view of one example of a reed according to various embodiments of the present invention; 
           [0013]      FIG. 6  comprises a flow chart of one approach of manufacturing the reed assembly (and receiver) according to various aspects of the present invention; 
           [0014]      FIG. 7  comprises a perspective view of another example of a reed according to various embodiments of the present invention. 
       
    
    
       [0015]    Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein. 
       DETAILED DESCRIPTION 
       [0016]    The present approaches provide a reed that is formed and connected to the receiver in such a way so as to reduce or eliminate reed movement in the horizontal direction. This significant reduction or elimination of reed movement in the horizontal (axial) direction reduces distortion of the receiver thereby improving receiver performance. In other words, axial vibrations are reduced or eliminated. In another advantage, the side portions of the reed can be constructed with thinner dimensions thereby reducing stiffness in these portions. This may allow and facilitate the construction shorter motor structures in one advantage. 
         [0017]    Referring now to  FIGS. 1, 2, 3, 4, and 5 , one example of a receiver  100  is described. The receiver  100  includes a top cup  102 , a bottom cup  104 , and a sound tube  106  with an opening  110 . A receiver motor is positioned in the interior of the receiver  100 . The motor includes a stack  118 , magnets  122 , a coil  114  and a first armature portion  110  (having a side arm or wing  111 ) and a second armature portion  112  (having a side arm or wing  113 ). A drive rod  122  is coupled to a diaphragm  116 . Magnetic flux lines  117  may be produced during operation to effectively create a magnetic circuit. 
         [0018]    Electrical current excites the coil  114  creating a magnetic flux  117  that moves reed  110 ,  112  in the direction indicated by the arrow labeled  122 , but not in the direction indicated by the arrow labeled  124 . More specifically, a central portion  121  if the armature moves while the wings  111  and  113  remain fixed with respect to the housing. 
         [0019]    Movement of the armature  110 ,  112  moves the drive rod  120  thereby moving the diaphragm  116 . Sound is produced and exits port  126  (through top cup  102 ). The sound traverses sound tube  106  and exits through opening  108 . 
         [0020]    The stack may be constructed of high permeability iron/nickel magnet material, for example. The reeds  110 ,  112 , may also be constructed of an iron/nickel compound (in one example, the material is approximately 50% of each of these materials). The reeds  110 ,  112  may be laminated together or connected by alternate methods. In another example, they may be glued together. In still another example the reeds  110 ,  112  may be injection molded and formed together as a single piece. In one example and in the cross-section, each of the reeds is 0.005 inches thick and 0.090 inches wide. Other dimensions of the cross-section of the reeds  110 ,  112  are possible. 
         [0021]    In other aspects, a thin insulation layer may be disposed between the reeds  110 ,  112  where the reeds  110 ,  112  contact (i.e., the central portion  121 ). In one advantage, the use of a layer of insulation may reduce the effects (or amounts) of eddy currents. In still other aspects, one of the reeds  110 ,  112  can be formed or constructed with very small bumps. Thus and in this approach, the two reeds  110 ,  112  may be separated by a small space because the bumps will not allow the two surfaces to be flush with each other. 
         [0022]    A pivot point  126  exists in the central portion where the reeds  110 ,  112  meet. In one aspect, the pivot point is the same for each reed  110 ,  112 . By pivot point and as used herein, it is meant that movement of the reeds  110 ,  112  rotates or turns about that point. Since the point is in the central portion of where the reeds  110 ,  112  meet, there can be no horizontal movement of the reeds  110 ,  112  in the direction indicated by the arrow labeled  124 . In fact, movement of the reeds  110 ,  112  can only be movement in the direction indicated by the arrow labeled  122 . It will be appreciated that the directions indicated by the arrows labeled  122  and  124  are orthogonal to each other. Movement of the reeds  110 ,  112  in the direction indicated by the arrow labeled  124  produces no sound and only produces negative effects (e.g., distortion) for the receiver  100 . It will also be understood that the pivot point is not located in the arm  111  of reed  110  or the arm  113  of reed  112 . If pivot points were located in these arms, then horizontal movement of the reeds  110 ,  112  would be possible and negative performance characteristics would occur. 
         [0023]    The reed  110 ,  112  moves only or substantially in the direction indicated by the arrows labeled  122 . The reed  110 ,  112  does not move or does not substantially move in the direction indicated by the arrows labeled  124 . 
         [0024]    Referring now especially to  FIG. 5 , in one aspect the cross sectional area of the reed in the central portion  121  is equal to the sum of the cross-sectional areas in the wing portions  111  and  113 . For example, the cross sectional area of reed  110  in the central portion is A 2 , the cross sectional area of reed  112  in the central portion is A 1 , the cross sectional area of reed  110  in the wing portion is A 4 , and the cross sectional area of reed  112  in the central portion is A 3 . A 1 +A 2 =A 3 +A 4 . By maintaining this relationship, no throttling of the magnetic flux occurs and the magnetic circuit represented by the flux lines  117  in optimized. 
         [0025]    Referring now to  FIG. 6 , one example of an approach for manufacturing the armature (or reed) assembly and the receiver described herein is described. At step  602 , the reeds (e.g., reeds  110 ,  112 ) are formed. They may be stamped from a sheet of material. They may be fabricated as individual units or in array. At step  604 , the material is annealed to give it specific magnetic properties (e.g., magnetic permeability). At step  604 , the two portions are secured together. For example, the two reeds may be glued together. Other attachment approaches can be used. Alternate attachments method may allow for forming of the reed before the annealing process. 
         [0026]    Referring now to  FIG. 7 , one example of another reed  700  used in the present approaches is described. In this example, the reed  700  is split at the top portion into a first top portion  702  and a second top portion  704 . The splitting of the top portion into two sub-portions is advantageous because by attaching the reed to both top and bottom of the stack a reduction of reed axial motion is achieved. This axial motion is related to an unwanted axial vibration in receivers. As mentioned, this configuration allows attachment of the reed  700  to both the sides of the stack as described above. The reed  700  also includes a middle portion  706  and a bottom portion  708 . 
         [0027]    Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. It should be understood that the illustrated embodiments are exemplary only, and should not be taken as limiting the scope of the invention.