This application claims the benefit of European Patent Application Serial No. EP 17173062.5, filed May 26, 2017, and titled “Receiver With Venting Opening,” which is incorporated herein by reference in its entirety.
The present invention relates to a receiver having a venting opening for boosting the low-frequency response of a receiver. In particular, the present invention relates to a receiver having an easy implementable venting opening between a back volume and the exterior of the receiver.
It is well established knowledge that the low-frequency response of a receiver can be boosted by providing a venting opening between the back volume of the receiver and the exterior of the receiver. By providing a properly dimensioned venting opening the back volume of the receiver may be vented via an orifice/acoustical impedance in a manner so that the back volume is fully vented at low frequencies (from around 5 Hz to around 1 kHz), i.e. the vented/open back volume configuration is favorable for low frequency reproduction. As the frequency increases the acoustical impedance also increases causing the back volume to be seen as a closed back volume at higher frequencies leaving a first resonance peak at the same frequency as the more favorable closed back volume configuration for high frequency reproduction. By carefully choosing the acoustical impedance as function of frequency the transfer/response curve of the receiver can be tailored to comply with specific demands.
Traditionally, venting openings are provided through a housing part of the receiver via a tube, a mesh or a damping cloth in order to provide a desired acoustical impedance. However, the traditional techniques for providing a venting opening are disadvantageous seen from a cost perspective as additional process steps and/or additional materials are often required. In addition, the risk of manufacturing defects or failures is affected by the additional process steps. Therefore, there is a need for providing venting openings in a more cost effective and easy manner.
It may be seen as an object of embodiments of the present invention to provide an advantageous arrangement in terms of manufacturing and costs for implementing a venting opening in a receiver in order to boost the low-frequency response of the receiver.
The above-mentioned object is complied with by providing a receiver assembly comprising
Thus, according to the first aspect the present invention relates to a sound generating receiver assembly comprising a venting opening through the membrane structure in order to boost the low-frequency response of the receiver assembly.
The membrane structure comprises a frame portion and a moveable diaphragm. The frame portion of the membrane structure may be an essential static portion that is rigidly connected to the assembly housing. According to the first aspect the acoustical venting opening may be positioned in the frame portion of the membrane structure.
The moveable diaphragm may be hinged to the frame portion and thus being moveable in relation thereto. The frame portion and moveable diaphragm of the membrane structure may form an integrated structure being made of the same material. Moreover, one or more openings may exist between the frame portion and the moveable diaphragm so that the latter is allowed to move relative to the frame portion. Alternatively, the frame portion and the moveable diaphragm may be discrete components being made of either the same or different materials. The moveable diaphragm may for example be made of a metal, such as nickel, steel, iron, aluminum, magnesium, or aluminum/magnesium alloys, such as AlMg3, or plastic material, such as a polymer, or any other material which is suitable for converting mechanical movements to acoustic pressure variations. The thickness of the membrane structure may be larger than 10 μm, such as larger than 20 μm, such as larger than 30 μm, such as larger than 40 μm.
A foil layer may be secured to the membrane structure in order to form one or more seal members across one or more openings between the frame portion and the moveable diaphragm. The foil layer may in principle be made of any formable and flexible material which is compliant enough to not hinder the diaphragm movements significantly. Examples of foil layer materials may be polymer layers including for example polyethylene terephthalate (PET) or polyurethane (PU). The thickness of the foil layer may be smaller than 40 μm, such as smaller than 30 μm, such as smaller than 20 μm, such as smaller than 10 μm, such as smaller than 8 μm, such as smaller than 6 μm, such as smaller than 4 μm.
It is advantageous that the existing foil layer may also be used to form an acoustical venting opening which may be aligned with the acoustical venting opening in the membrane structure. The acoustical venting opening in the foil layer may advantageously be made using laser before or after assembling the receiver. Moreover, as a laser is a high-precision tool the opening in the foil layer may be made with high accuracy. Even further the manufacture is in principle free to choose an opening size with enough precision to tune the venting of the receiver to specific demands, i.e. to a specific response curve.
The dimensions of the acoustical venting opening in the foil layer may be smaller than the dimensions of the acoustical venting opening in the membrane structure whereby the acoustical properties of the venting opening may be given by the dimensions of the acoustical venting opening in the foil layer.
The acoustical venting opening connecting an interior volume of the receiver assembly to an exterior volume outside assembly housing may comprise a tube forming the acoustical passage through the membrane structure. The tube may be secured to the membrane structure using an appropriate sealing material.
In order to generate sound the moveable diaphragm should be moved in accordance with an applied drive signal. Thus, the receiver assembly may further comprise a drive unit for driving the moveable diaphragm of the membrane structure in response to an applied drive signal. The drive unit may in principle be any kind of drive unit, such as a moving armature type drive unit. The moving armature type drive unit may comprise a U-shaped armature comprising an integrated drive pin. Alternatively, the drive pin may be discrete component being inserted between the U-shaped armature and the moveable diaphragm.
The assembly housing may comprise a can part and a cover part. At least part of the frame portion of the membrane structure may advantageously form a seal between the can part and the cover part.
At least one of the can part and the cover part may comprise at least one opening to allow one or more wires to extend from the interior volume of the receiver assembly to an exterior volume outside the receiver assembly. In one embodiment, at least one of the can part and the cover part may additionally or alternatively comprise at least one depression/recess formed at an edge portion to form an opening. The depression(s)/recess(es) may be formed by exerting a pressure at the edge portion at the required position. Alternatively, the depression(s)/recess(es) may be formed as part of a moulding process when manufacturing at least one of the first and second housing parts. The depression(s)/recess(es) leave(s) space for wires, such as wires for providing drive signals to the drive unit.
The cover part may comprise a sound outlet opening and an acoustical venting opening forming an acoustical passage through the cover part, said acoustical venting opening being aligned with the acoustical venting opening of the membrane structure. The venting opening of the cover part may also be aligned with a venting opening in a foil layer.
The acoustical venting opening of the receiver assembly may acoustically connect a back volume of the receiver assembly to the exterior outside assembly housing.
In a second aspect the present invention relates to a receiver assembly comprising
Thus, according to the second aspect the acoustical venting opening is provided through a foil layer. This is advantageous in that the opening in the foil layer may be made using a laser either before or after assembling the receiver. Moreover, as a laser is a high-precision tool the opening in the foil layer may be made with high accuracy.
The membrane structure may be implemented as disclosed in connection with the first aspect. The foil layer comprising the acoustical venting opening may form part of a foil layer secured to the membrane structure, said foil layer also forming one or more seal members across one or more openings between the frame portion and the moveable diaphragm. The assembly housing may comprise a can part and a cover part, and the acoustical venting opening may go through the cover part.
In an alternative implementation the foil layer comprising the acoustical venting opening may be a separate piece of foil layer which is separated from a foil layer being secured to membrane structure. Also in this alternative implementation the assembly housing may comprise a can part and a cover part, wherein at least part of the frame portion of the membrane structure forms a seal between the can part and the cover part. The separate piece of foil layer may be secured to the can part so that the acoustical venting opening may go through the can part.
The properties of the foil layer may be similar to those addressed in connection with the first aspect. Also, the drive unit addressed in connection with the first aspect may be applied in connection with the receiver assembly according to the second aspect.
In a third aspect the present invention relates to a receiver assembly comprising:
Thus, according to the third aspect of the present invention the drive pin and the armature may be formed in one part; i.e. as an integral unit. In the context of the present invention, the term “formed in one part” should be understood as an element which is formed without a joint. Thus, the drive pin and the armature are not formed as two separate elements being subsequently assembled.
Traditionally, assembling of receiver assemblies require multiple step including positioning of the drive pin relative to the armature and the moveable diaphragm. This can deform the armature and/or the drive pin. Furthermore, gluing of the drive pin to the armature requires a curing step. During this curing step the drive pin may move.
By providing the drive pin and the armature as an integral units formed in one part or piece, assembling of receiver assemblies may result in a lower reject rate, as some of the traditional process steps, such as gluing and curing may be omitted.
Furthermore, a separate drive pin which is joined with an armature is traditionally made from beryllium copper e.g. by clamp fitting and subsequently sealing e.g. by use of an adhesive. By forming the drive pin and the armature as an integral unit in one part, the use of beryllium copper can be avoided whereby the risk of inhalation of dust containing beryllium which can cause serious lung decease may be avoided.
The drive pin and the armature may comprise a bent transition portion, where the armature may extend in the first direction from the transition portion and the drive pin may extend in the second direction from the transition portion. The bent transition portion may as an example be formed by moulding or by bending of the integral unit forming the armature and the drive pin.
The angle between the first direction and the second direction may be in the range of 60 to 120 degrees, such as in the range of 70 to 110 degrees, such as in the range of 80 to 100 degrees.
The present invention will now be described in further details with reference to the accompanying figures.
While the invention is susceptible to various modifications and alternative forms specific embodiments have been shown by way of examples in the drawings and will be described in details herein. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
In its broadest aspect the present invention relates to a receiver having a venting opening between a back volume of the receiver and the exterior of the receiver, i.e. outside world. The venting opening may be provided through the membrane of the receiver, through a cover part of a receiver housing and/or through a can part of a receiver housing. The venting opening is provided for boosting the low-frequency response of the receiver.
Referring now to
The frame portion is rigidly connected to the receiver housing whereas the moveable diaphragm is hinged to the frame portion in a manner that allows it to move in relation thereto. A foil layer (not shown) is secured to the membrane structure with the aim of providing one or more seal members across one or more openings between the frame portion and the moveable diaphragm.
The interior of the receiver 100 defines a front volume 107 and a back volume 106 being acoustically connected via a compensation opening 104. Moreover, the back volume 106 is acoustically connected to the exterior 110 of the receiver 100 via a venting opening 105 in the membrane structure 109. A proper tuning of the venting opening 105 using for example a laser will boost the low-frequency response of the receiver. In a preferred embodiment the foil layer secured to the membrane structure, cf. for example
In order to generate sound the moveable diaphragm may be moved by a drive unit (not shown) which may include a moving armature type drive unit, cf.
Referring now to
The assembly of the membrane structure 203 and the foil layer 204 is adapted to be secured to the cover part 201 which may be extended as indicated by the dotted portion 202. When assembled (as indicated by the arrows) the membrane structure 203 and the foil layer 204 separate the front volume 207 from the back volume 209 although these volumes are acoustically connected via the compensation opening 205. The back volume 209 is acoustically connected to the exterior 208 of the receiver via the venting opening 206 in order to boost the low-frequency response of the receiver.
Turning now to
Referring now to the embodiments 500, 509 shown
In the embodiment shown in
In the embodiment 600 depicted in
In conclusion the present invention addresses a sound generating receiver having an easy implementable venting opening for boosting the low-frequency response of the receiver. A laser processed foil layer may advantageously be applied for tuning the acoustical properties of the venting opening.
Number | Date | Country | Kind |
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17173062.5 | May 2017 | EP | regional |