This patent application relates to armature designs for receiver assemblies which provide performance with low levels of vibration.
Hearing instrument acoustic gain is primarily limited by feedback of the output signal back to the input of the device. Mild amounts of feedback change the transfer function of the system, thereby coloring the sound output. Larger amounts of feedback will cause instability and oscillation (squealing noises). There are multiple paths for feedback, one of which is the mechanical vibration of the hearing instrument receiver. The case of the receiver vibrates in reaction to the motion of the internal parts. This vibration, in turn, couples to the diaphragm in the hearing instrument microphone, either directly, or indirectly through the hearing instrument case moving the air that is near the microphone.
The vibration of receivers can be largely cancelled out by connecting a pair of receivers together such that their primary direction of vibration is in opposition. The motion of the two devices then cancels, greatly reducing the net vibration. Unfortunately, the receivers have vibration components in both the vertical and horizontal directions. When two receivers are combined together, the vertical components cancel, but the horizontal portion adds to the vibration.
Thus, there is a need for receivers that have vibration strictly in the vertical direction, with no vibration in the horizontal direction. There is also a need to make the hearing instrument as small as possible, to improve the fit of the device into the ear canal, or to reduce the visibility of the instrument. The need for a smaller sized hearing instrument creates a need for a smaller sized receiver. The receiver size can be reduced by folding the armature, such as that design seen in known receivers. Armatures 2, 4, 6 which are used in balanced armature receivers typically use a U or E shaped armature (see
A flat E-shaped armature 4, as shown in
For a more complete understanding of the disclosure, reference should be made to the following detailed description and accompanying drawings wherein:
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.
While the present disclosure is susceptible to various modifications and alternative forms, certain embodiments are shown by way of example in the drawings and these embodiments will be described in detail herein. It will be understood, however, that this disclosure is not intended to limit the invention to the particular forms described, but to the contrary, the invention is intended to cover all modifications, alternatives, and equivalents falling within the spirit and scope of the invention defined by the appended claims.
The present approaches generally relate to armatures for receiver assemblies which reduce vibration in one or both of the horizontal and vertical directions. The vertical portion is primarily due to the vertical motion of the armature, and to a lesser extent, to the motion of the diaphragm assembly. In prior approaches, vertical motion of the armature tip typically causes a small amount of horizontal motion near the pivoting end of the armature. In the approaches described herein, the horizontal motion can be reduced or eliminated if, for example, the pivoting end is constructed in the same plane as the moving portion of the armature.
The present approaches provide devices that are of a sufficiently small and compact size to be used in miniature audio devices. The small size (as compared to prior devices) is obtained at least in part by the positioning of the center tine relative to the outer tines. In some examples, this disposition of the components minimizes the height of the overall magnetic assembly (including, for example, the armature, coil, and yokes) because the height of the outer tines can be reduced. Thus, as compared to previous approaches and in some aspects, the outer tines no longer extend above the yoke thereby reducing the overall height of the assembly as compared to previous approaches.
In some aspects, the substantial reduction or elimination of horizontal movement of the center tine is obtained by the coupling of the center tine to a length-wise section (e.g., a side surface or an underside) of the side tines of the armature. In other examples, the center tine is coupled to a cross-bar like connecting portion or member such that approximately one-half of the area of the connecting portion is above the center tine (at the connection point) and approximately one half of the area of the connecting portion is below the center tine (at the connection point). The stiffness of the two sections of the connecting portion (e.g., as measured in newtons/meter) is substantially equal thereby substantially reducing or eliminating horizontal vibrations of the center tine when the center tine moves in a vertical (i.e., up/down) direction.
In other aspects, a receiver assembly or other audio device is provided that is of a small and compact size, uses a flat and thin armature, and resists horizontal vibrations. In this respect, the armature is thin and flat while at least portions of the yoke couple to the side tines of the armature. In so doing, the yoke provides a path for the magnetic flux to flow thereby allowing use of the flat and thin armature. Consequently, the overall dimensions of the receiver assembly are reduced as compared to previous devices. Resistance to horizontal vibrations is additionally provided by the long and flat configuration of the armature.
In many of these embodiments, an armature apparatus for use in an acoustic device includes a first tine member, a second tine member, a center tine member, and a connecting portion. The first tine member has a first length, a first width, and a first thickness. The first length is greater than the first width; the first width is greater than the first thickness, and the first width and the first length define a first surface. The second tine member has a second length and a second width. The second length is greater than the second width and the second length and the second width defines a second surface. The first surface of the first tine member generally faces the second surface of the second tine member and the first surface is disposed in generally parallel relation to the second surface. The center tine member has a third length and the third length is generally parallel to the first length and the second length. The connecting portion couples the center tine member to the first surface along the first length and to the second surface along the second length. The coupling is effective to substantially eliminate vibrations along the third length of the center tine member (i.e., in the horizontal direction). The center tine member is generally disposed in a plane extending between the first tine member and the second tine member and the plane divides the first surface of the first tine member and the second surface of the second tine member to create two areas in each of the first tine member and the second tine member.
In some examples, the connecting portion is coupled to a first underside of the first tine member via a first folded section and to a second underside of the second tine member via a second folded section. The first underside is defined by the first thickness and the first length and the second underside is defined by the second thickness and the second length. In some aspects, the first folded section extends generally in the direction of the first width and the second folded section extends generally in the direction of the second width. In some others of these embodiments, the connecting portion is coupled to the first surface of the first tine member and to the second surface of the second tine member.
An electrical coil may be configured to surround the center tine member. In some of these examples, the coil does not extend beyond the first width or the second width. In other aspects, a yoke member is coupled to the armature and the first tine member and the second tine member do not extend beyond the yoke member in the direction of the first width and the second width.
In others of these embodiments, an armature apparatus for use in an acoustic device includes a first tine member, a second tine member, a center tine member, and a connecting member. The first tine member has a first length and a first width. The first length is greater than the first width and the first width and first length define a first surface. The second tine member has a second length and a second width. The second length is greater than the second width and the second length and the second width define a second surface. The first surface of the first tine member generally faces the second surface of the second tine member and the first surface is disposed in generally parallel relation to the second surface. The center tine member has a third length and the third length is generally parallel to the first length and the second length. The connecting member is coupled to the center tine member, the first tine member, and the second tine member. The center tine member is generally disposed in a plane extending between the first tine member and the second tine member and the plane divides the first surface of the first tine member and the second surface of the second tine member to create two areas in each of the first tine member and the second tine member. The plane also divides a third surface of the connecting member into two generally equal areas, a disposition of the two generally equal areas being effective to substantially eliminate vibrations along the third length of the center tine member (i.e., in the horizontal direction).
In some examples, the center tine member is coupled to the connecting member via a slot through the connecting member. In other examples, the center tine member is coupled to the connecting member via welding or some adhesive. In some other approaches, the first tine member, second tine member, and connecting member are formed integrally together.
In others of these embodiments, an acoustic assembly includes an armature, a coil, a first yoke, and at least one magnet. The armature includes a first outer tine member with a first length, a second outer tine member with a second length, and a center tine member. The center tine member is coupled to the first tine member via a connecting portion. The coil surrounds the center tine member. The at least one magnet is disposed between the first yoke member and the second yoke member. The first outer tine member is coupled to the first yoke member along the entire first length, and the second outer tine member is coupled to the first yoke member along the entire second length. The first yoke member is configured to provide a path for the flow of a flux produced in the assembly to the connecting portion to move at least portions of the armature in a vertical direction that is generally perpendicular to the first length and the second length. A second yoke member is connected to the first tine member and the second tine member. The first outer tine member is coupled to the second yoke member partially along first length, and the second outer tine member is coupled to the second yoke member partially along the second length.
In other aspects, the assembly includes a housing. The housing is separate from the first yoke member and the second yoke member. In some examples, the housing is configured to keep magnetic signals substantially confined to the assembly.
A plane in which the center tine 103 is disposed extends to divide each of the facing surfaces (i.e., the surfaces of each tine 114 that face each other) into two areas. In one example, these areas are approximately equal. In other examples, these areas are unequal (but not minimal in size). For example, the two areas may be in a ratio of approximately 30% to approximately 70% or approximately 60% to approximately 40%. Other examples of ratios are possible. As shown, the folded sections 118 and 120 couple the center tine 103 to the tines 114 by extending downward. This placement of the center tine 103 relative to the outer tines 114 allows the size of the overall assembly to be reduced since, for example, the coil structure 108 need not extend beyond (or much beyond) the tines. The coil structure 108 also does not extend beyond the yoke 104. In one example, and as best seen in
Additionally, coupling of the folded sections 118 and 120 to the underside of the tines 114 along the lengths of the tines (the lengths being in the direction indicated by the axis labeled 130 in
In operation, the coil structure 108 induces a flux in the armature 102. The flux flows to the magnets 106 which move the tip of the center tine 103 up and down (in the direction indicated by the arrow labeled 131). The center tine 103 is connected through a connecting strap or wire 107 to the movable portion 111 of the diaphragm assembly 109, such that motion of the center tine causes proportional motion of the diaphragm assembly. This in turn pushes air in and out of an opening 115 in the receiver housing, thus generating sound outside of the housing. The housing includes a lower section 101 and an upper section 113.
In the above-mentioned examples, coupling the center tines to the side tines along a length of the side tines provides strength and support such that horizontal movement (i.e., vibrations) is prevented from occurring or substantially prevented from occurring in the center tines (e.g., horizontal movement is shown as being along the axis labeled 151 in
The substantial reduction or elimination of horizontal movement of the center tine 192 (indicated by the arrow labeled 193) is obtained at least in part by the coupling of the center tine 192 to the connection portion 194 such that approximately one-half of the area of the connection portion 194 is above the center tine 192 (at the connection point or connection area) and approximately one half of the area of the connection portion 194 is below the center tine 192 (at the connection point or connection area). The stiffness of the two sections of the connection portion 194 (e.g., as measured in newtons/meter) is substantially equal thereby substantially reducing or eliminating horizontal vibrations of the center tine 192 when the center tine 192 move is a vertical (i.e., up/down) direction (indicated by the arrow labeled 195).
More specifically, upward movement of the center tine 192 in the direction of the arrow 195 causes the upper portion of the connection portion 197 to move in the direction indicated by the arrow labeled 197 and the bottom part of the connection portion 194 to move in the direction indicated by the arrow labeled 199. However, the stiffness of the two equal portions of the connection portion 194 is configured to be equal or approximately equal and hence any force that could be produced to move the center tine 192 in the direction of arrow 193 is prevented from being formed.
As with some of the other examples described herein, the positioning of the center tine 192 with respect to the outer tines, allows the overall structure in which the armature fits to be reduced. For example, any coil that is wound around the center tine does not extend above a yoke. In addition, the outer tines do not extend beyond the yoke.
In one example, the center tine 192 is approximately 4.0 mm long, approximately 1.5 mm wide, and approximately 0.15 thick. The connection portion 194 is approximately 2.5 mm long, approximately 0.6 mm high, and approximately 0.15 mm thick. The outer tines 193 are approximately 5.0 mm long, approximately 0.6 mm wide, and approximately 0.15 mm thick. Other examples of dimensions may also be used.
Similarly,
The receiver assembly 250 is configured to be of a small and compact size, uses a flat and thin armature 256, and resists horizontal vibrations (in the direction indicated by the arrow labeled 255). In this respect, the armature 256 is thin and flat (e.g., approximately 0.15 mm thick, approximately 5.0 mm long, and approximately 1.9 mm wide) while at least portions of the yoke 252 couple to the side tines of the armature 256. In so doing, the yoke 252 provides a path for the magnetic flux to flow along the armature 256 thereby allowing use of a flat and thin armature. Consequently, the overall dimensions of the receiver assembly 250 are reduced as compared to previous devices. Resistance to horizontal vibrations in the direction of the arrow labeled 255 is provided by the long and flat configuration of the armature.
In one example, the overall length of the assembly 250 is approximately 5.0 mm. The height of the yoke is approximately 1.0 mm. The height of the coil is approximately 0.6 mm. Other examples of dimensions are possible.
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.
This patent claims benefit under 35 U.S.C. §119 (e) to U.S. Provisional Application No. 61/177,106 entitled “Low Axial Vibration Receiver Armature” filed May 11, 2009 having attorney docket number PO9011 the content of which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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61177106 | May 2009 | US |