Microphone assembly with particle filtration system

Abstract

A microphone assembly having a particle filtration system. A microphone filter system may include an outer support structure, at least one filter layer, an inner support structure, and a sleeve. The microphone filtration system is configured to seal a transducer chamber of the microphone assembly from an external environment, and to trap particles that may accumulate and corrode a transducer contained by the transducer chamber. At least one filter layer of the particle filter system provides a minimum effective report value (MERV) level of greater than or equal to 13 while minimizing attenuation and distortion of acoustic waves entering the transducer chamber.

Description

Background Art

[0001] A microphone is a transducer that converts the air pressure changes of sound waves into electrical signals. Microphones are used in many applications and often need to be used by more than one user. Different particles such as smoke, dust, pollen, and aerosols can enter the transducer chamber and damage the transducer housed therein. BRIEF DESCRIPTION OF THE DRAWINGS

[0002] The detailed description is described with reference to the accompanying drawings.The use of the same reference numbers in different instances in the description and the drawings may indicate similar or identical items.

[0003] Figure 1 is an isometric side view of a microphone assembly with a particle filtration system according to an exemplary embodiment of the present disclosure.

[0004] Figure 2 According to an exemplary embodiment of the present disclosure Figure 1 An exploded side view of a microphone assembly with a particle filter system is shown in FIG.

[0005] Figure 3 According to an exemplary embodiment of the present disclosure Figure 1 A cross-sectional side view of a microphone assembly with a particle filter system is shown in FIG.

[0006] Figure 4 is an isometric side view of a microphone assembly with a particle filter system having an outer frame according to an exemplary embodiment of the present disclosure.

[0007] Figure 5 According to an exemplary embodiment of the present disclosure Figure 4 An exploded side view of a microphone assembly with a particle filter system having an outer frame is shown in FIG. DETAILED DESCRIPTION

[0008] Although the subject matter has been described in language specific to structural features and / or process operations, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

[0009] Overview

[0010] Typical portable microphone filters include pop filters with screens made of metal, nylon, and open-cell and / or polyurethane foams, designed to prevent "popping" caused by plosives. Plosives are sounds associated with consonants in which the flow of air from the user's lungs is interrupted by the closure of the mouth, followed by a sudden release of breath. The impact of air reaching the microphone causes a deformation of the electrical signal transmitted by the microphone's transducer, resulting in acoustic reflections.

[0011] Portable sound filters made of open-cell and / or polyurethane foam and windshields made of open-cell and / or polyurethane foam can cover the transducer chamber of a microphone. These devices are intended to reduce acoustic reflections but do not prevent debris from entering the transducer chamber. Portable windshield bags made of polyurethane foam and / or fur, synthetic fur, or other materials and "baskets" or "sound shields" with fully enclosed chambers lined with open-cell foam or fur are intended to block wind and can significantly attenuate sound waves entering the microphone.

[0012] The Minimum Efficiency Reporting Value (MERV) is a rating derived from a test method developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers. The MERV rating reports the ability of a filter to capture particles between 0.3 microns and 10 microns (μm). The higher the MERV rating, the better the filter captures a particular type of particle.

[0013] The present disclosure describes exemplary embodiments of a microphone assembly having a MERV-rated particle filtration system that prevents debris and particles from reaching the microphone transducer while minimizing sound distortion and attenuation of the original sound waves. Specific embodiments

[0015] Overall reference Figures 1 to 3 , the microphone assembly 100 includes a transducer 102 housed in a transducer chamber 112, a particle filter system 101, and a microphone body 104. In the transducer chamber 112, the transducer 102 converts sound waves into electrical signals (not shown) and transmits the electrical signals to a receiver through an output terminal (not shown). The microphone assembly 100 may be a wired microphone (also referred to as a cable microphone) or a cordless microphone connected to a sound system (not shown) via a cable.

[0016] The microphone body 104 houses components of the microphone assembly 100, such as, but not limited to, an internal power source such as a battery (not shown), a built-in transmitter (not shown), or an output cable. The output cable transmits the electrical signal to a sound system, where the electrical signal is converted into audio. In an exemplary embodiment, the microphone body 104 may define a handle to be held by a user or disposed on a stand (not shown).

[0017] In an exemplary embodiment, microphone assembly 100 may be a dynamic microphone (also known as a moving coil microphone), a condenser microphone (also known as a capacitive microphone or an electrostatic microphone), a ribbon microphone, or another microphone used in sound recording or playback.

[0018] In an exemplary embodiment where the microphone assembly 100 is a dynamic microphone, the transducer 102 may include a diaphragm, a coil, and a magnetic core (not shown). The coil may be attached to the diaphragm and wound around the magnetic core. When sound enters the transducer chamber 112, the coil vibrates with the diaphragm. When the diaphragm vibrates, the coil moves back and forth in the magnetic field generated by the magnetic core. The movement of the coil in the magnetic field generates an electrical signal corresponding to the sound picked up by the transducer. In an exemplary embodiment, the diaphragm may be made of metal (e.g., aluminum, etc.) or plastic.

[0019] In an exemplary embodiment where the microphone assembly 100 is a condenser microphone, the transducer 102 may include a pair of capacitor plates (not shown) including a front plate (also referred to as a diaphragm) and a back plate and a voltage source. The voltage source may be a battery or a phantom power supply. In a condenser microphone, the power supply supplies voltage to the pair of capacitor plates. The diaphragm vibrates when impacted by sound waves, thereby changing the distance between the pair of capacitor plates and thus changing the capacitance. Specifically, when the plates are brought closer together, the capacitance increases and a charging current occurs. When the plates are further apart, the capacitance decreases and a discharge current occurs. These changes in capacitance can be used to measure audio signals.

[0020] The particle filtration system 101 may include an external support structure 106, at least one filter layer 108, and a sleeve 110. The external support structure 106 is configured to support at least one filter layer 108. The external support structure 106 may be composed of a textile material, a plastic (e.g., nylon, etc.), a solid foam, a metal, or a combination thereof. In other embodiments, the particle filtration system may include an internal support structure that is arranged between at least one filter layer 108 and the sleeve 110 and / or between the sleeve 110 and the transducer chamber 112. The internal support structure may be composed of the same material as the external support structure 106 or may be composed of a material different from the external support structure 106. The internal support structure may be composed of a textile material, a plastic, a solid foam, a metal, or a combination thereof.

[0021] The particle filter system 101 reduces the accumulation of particles of foreign matter on the transducer 102, thereby extending the life of the microphone assembly 100. The particle filter system 101 can help reduce the frequency of required maintenance and cleaning of the microphone assembly 100. In addition, the particle filter system 101 can reduce the need to restore the microphone assembly 100 and / or replace parts of the microphone assembly 100.

[0022] The particle filtration system 101 can capture smoke, spray, droplet nuclei, dust, mold spores, dust mites, pollen, and aerosols, among other particles, thereby preventing them from reaching the transducer chamber 112 and causing accumulation and damage to the transducer 102. In an exemplary embodiment, the particle filtration system 101 captures particles to reduce the spread of viruses and bacteria by preventing the particles from attaching to surfaces of the microphone assembly 100 (e.g., the transducer chamber 112), thereby reducing the user's exposure to particles left on the microphone assembly 100 by previous users.

[0023] In an embodiment, the external support structure 106 may be composed of a reticulated foam, or another type of porous, low-density, open-cell solid foam. For example, the external support structure 106 may be composed of a reticulated polyester polyurethane foam or a reticulated polyether polyurethane foam or a combination thereof. In an embodiment, the external support structure 106 may have a porosity less than or equal to about fifty-five pores per square inch (55 PPI). For example, the external support structure 106 may have a porosity from 4 PPI to about 55 PPI. In an embodiment, the external support structure may have a porosity of about 10 PPI to about 45 PPI. In other embodiments, the support structure may be composed of a low-density closed-cell foam.

[0024] In an exemplary embodiment of the present disclosure, at least one filter layer 108 has a MERV rating of 13 or higher. At least one filter layer 108 can capture at least fifty percent (50%) of particles between 0.3 μm and 1 μm. At least one filter layer 110 can capture greater than or equal to about eighty-five percent (85%) of particles between 1 μm and 3 μm. At least one filter layer 110 can capture greater than or equal to about ninety percent (90%) of particles between 3 μm and 10 μm.

[0025] In an exemplary embodiment of the present disclosure, at least one filter layer 108 has a MERV rating of 14 or above. At least one filter layer 108 can capture at least seventy-five percent (75%) of particles between 0.3 μm and 1 μm. At least one filter layer 110 can capture greater than or equal to about ninety percent (90%) of particles between 1 μm and 3 μm. At least one filter layer 110 can capture greater than or equal to about ninety-five percent (95%) of particles between 3 μm and 10 μm.

[0026] In an exemplary embodiment of the present disclosure, at least one filter layer 108 has a MERV rating of 15 or above. At least one filter layer 108 can capture at least eighty-five percent (85%) of particles between 0.3 μm and 1 μm. At least one filter layer 110 can capture greater than or equal to about ninety percent (90%) of particles between 1 μm and 3 μm. At least one filter layer 110 can capture greater than or equal to about ninety-five percent (95%) of particles between 3 μm and 10 μm.

[0027] In an exemplary embodiment of the present disclosure, at least one filter layer 108 has a MERV rating of 16 or higher. At least one filter layer 108 can capture at least ninety-five percent (95%) of particles between 0.3 μm and 1 μm. At least one filter layer 110 can capture greater than or equal to about ninety-five percent (95%) of particles between 1 μm and 3 μm. At least one filter layer 110 can capture greater than or equal to about ninety-five percent (95%) of particles between 3 μm and 10 μm.

[0028] In an exemplary embodiment, at least one filter layer 108 may be composed of an electrostatic media filter, a nonwoven fabric filter, an activated carbon filter, or a combination thereof. In an exemplary embodiment, the particle filtration system 101 may be composed of one or more layers of electrostatic media filters, one or more layers of nonwoven fabric filters, and one or more layers of activated carbon filters.

[0029] Electrostatic media filters can be made of synthetic fibers that utilize mechanical filtration and provide an electrostatic charge. The electrostatic charge of the synthetic fibers can be inherent to the material or added during production by processes such as electrostatic induction, friction charging, corona charging, etc. The electrostatic attraction effect of the electrostatic media filter attracts particles to the synthetic fibers, thereby providing improved filtration efficiency over uncharged media. Electrostatic media filters can also provide reduced pressure drop. In an exemplary embodiment, the electrostatic media filter can be used alone or in combination with different filter layers 108.

[0030] The nonwoven fabric filter can be manufactured as an engineered fabric comprising a random arrangement of filaments or fabrics. The nonwoven fabric filter can be a meltblown or spunbond nonwoven media filter. In an exemplary embodiment, the nonwoven fabric filter can be used alone or in combination with different filter layers 108.

[0031] The activated carbon filter may use carbon that has been treated with oxygen to make the carbon more absorbent through an adsorption process. During the adsorption process, gas molecules adhere to the pores of the activated carbon. The adsorption process allows the activated carbon to filter out gases, odors, and / or volatile organic compounds (VOCs) from the air that enters the transducer chamber 112 and contacts the transducer 102. In an exemplary embodiment, a nonwoven fabric filter may be used alone or in combination with a different filter layer 108.

[0032] In an exemplary embodiment where at least one filter layer 108 is an electrostatic media filter and / or an activated carbon filter, at least one filter layer 108 has a thickness between about 0.1 inches and about 0.5 inches. In an exemplary embodiment where at least one filter layer 108 is a nonwoven fabric filter, at least one filter layer 108 has a thickness between about 0.1 inches and about 0.5 inches and / or a density less than or equal to 120 grams per square meter (GSM).

[0033] At least one filter layer 108 minimizes distortion and attenuation of the original sound waves received by transducer 102. In an exemplary embodiment, at least one filter layer 108 can minimize the distortion of the original sound waves by an average value between about 0.1 decibels (dB) and about 5 dB (i.e., 1 V / Pa) from a frequency between about 20 Hz and about 20,000 Hz.

[0034] In an exemplary embodiment, the sleeve 110 is removably attached to the transducer chamber 112 so as to cover the periphery of the transducer chamber 112. The sleeve 110 can have different shapes and / or sizes based on the type and size of the microphone assembly 100 and the transducer chamber 112. The sleeve can be composed of a reticulated foam (such as that described above). In other embodiments, the sleeve can be composed of a textile material, plastic, solid foam, or a combination thereof.

[0035] Sleeve 110 is configured to secure at least one filter layer 108 to transducer chamber 112. In an exemplary embodiment, sleeve 110 may include fasteners and / or adhesives to secure at least one filter layer 108 to transducer chamber 112, prevent at least one filter layer 108 from sliding out of transducer chamber 112, and secure a seal of particle filtration system 101. For example, sleeve 110 may include an epoxy adhesive, a polyurethane adhesive, and / or a polyimide adhesive, or a combination thereof, that bonds sleeve 110 to filter layer 108. The material selected for the adhesive does not generate interference with sound waves received by transducer 102.

[0036] In other embodiments, at least one filter layer 108 may be sewn into the sleeve 110. The thread used to secure the at least one filter layer 108 and the sleeve 110 may be selected from at least one of a spun thread, a co-spun thread, a textured thread, or a monofilament thread or a bonded thread. The material selected for the thread does not generate interference with the sound waves received by the transducer 102.

[0037] In an exemplary embodiment, the microphone body 104 may include a ridge 122 around the periphery of the transducer chamber 112. The particle filtration system 101 may fit into the ridge 122 to create a seal 120. In other exemplary embodiments, the microphone body may include an outer ring. The sleeve 110 may conform to the shape of the ridge 122 or outer ring to seal the transducer chamber 122 from the external environment. In other embodiments (not shown), the particle filtration system may include a gasket between the sleeve 110 and the transducer chamber 112. The gasket may be composed of rubber, plastic, metal, or another material that will seal the transducer chamber 112 from the external environment.

[0038] Overall reference Figures 4 to 5 , the particle filtration system 101 may include an outer frame 114, an outer support structure 106, at least one filter layer 108, an inner support structure 116, and a sleeve 110. In other embodiments (not shown), the particle filtration system may not include a sleeve, and the inner support structure provides the necessary support for the at least one filter layer to be coupled to the transducer assembly.

[0039] The particle filter system 101 is configured to cover the entire transducer chamber 112. In an exemplary embodiment, the external frame 114 can accommodate the external support structure 106. The external support structure is configured to support at least one filter layer 108. The internal support structure 116 can be arranged in the at least one filter layer 108 and the sleeve 110 and / or between the sleeve 110 and the transducer chamber 112. At least one filter layer 108 seals the transducer chamber 112 without contacting the external environment. In an exemplary embodiment (not shown), the internal support structure can accommodate at least a second filter layer. The internal support structure can be a frame with vertical and / or horizontal members that separate at least one filter system from the transducer chamber. The internal support structure can include a plurality of parallel rings (not shown) around the periphery of the transducer chamber.

[0040] In other embodiments, the particle filtration system includes at least one filter layer having a MERV rating of 13 or higher stretched on a support frame. The support frame can be circular, oval, square, rectangular, etc. The support frame can be coupled to the microphone assembly via a mounting bracket or shaft having a fastener (e.g., a clip, a clamp, etc.). The filtration system may include a support structure attached to the front and / or back of the support frame, wherein the support structure (such as the external support structure and the internal support structure described herein, etc.) can be made of plastic, solid foam, metal, or a combination thereof. This embodiment of the particle filtration system can be used as a pop filter and attenuate sounds from recorded plosives, etc.

[0041] In an exemplary embodiment (not shown), at least one filter layer 108 can be further divided into a top cover filter layer and a peripheral filter layer, wherein the peripheral filter layer is generally cylindrical. The top cover filter layer can be attached to the peripheral filter layer by thermoplasticizing or heat sealing the top cover filter layer and the peripheral filter layer together. In other embodiments, the top cover filter layer can be adhered or sewn into the peripheral filter layer. It should be understood that depending on the shape of the microphone assembly 100, at least one filter layer 108 can be divided into filter layers having different structural shapes.

[0042] Although the subject matter has been shown and described in detail in the drawings and the foregoing description, the same is considered to be illustrative and not restrictive in character. In reading the claims, it is intended that when words such as "a", "an", or "at least one" are used, it is not intended to limit the claims to only one item unless expressly stated to the contrary in the claims. Unless otherwise specified or limited, the terms "mounted", "connected", and "coupled" and variations thereof are used broadly and include direct and indirect mounting, connection, support, and coupling. Furthermore, "connected" and "coupled" are not limited to physical or mechanical connections or couplings.

Claims

1. A microphone assembly, comprising: a transducer configured to convert air pressure changes of the sound waves into electrical signals; a transducer chamber configured to house the transducer; as well as A particle filtration system, wherein the particle filtration system comprises: an outer support structure having a porosity of less than or equal to about fifty-five pores per square inch (55 PPI), a filter layer, wherein the filter layer is contained by the outer support structure, wherein the filter layer comprises at least one item from the group consisting of: at least one layer of electrostatic media filter, at least one layer of activated carbon filter, and at least one layer of nonwoven fabric filter, a sleeve disposed between the filter layer and the transducer chamber, the sleeve being configured to retain the filter layer and prevent the filter layer from sliding from the transducer chamber, wherein the filter layer provides a minimum efficiency reporting value (MERV) rating of greater than or equal to thirteen (13), and the filter layer captures at least fifty percent (50%) of particles between 0.3 μm and 1 μm, greater than or equal to approximately eighty-five percent (85%) of particles between 1 μm and 3 μm, and greater than or equal to approximately ninety percent (90%) of particles between 3 μm and 10 μm.

2. The microphone assembly according to claim 1, wherein: The at least one layer of electrostatic media filter includes electrostatically charged synthetic fibers.

3. The microphone assembly according to claim 1, wherein: The at least one layer of nonwoven fabric filter comprises an engineered fabric having a random arrangement of filaments or fabrics, wherein the nonwoven fabric filter is at least one of the following group, the group consisting of: meltblown nonwoven media filters and spunbond nonwoven media filters.

4. The microphone assembly according to claim 3, wherein: The filter layer has a thickness between about 0.1 inches and about 0.5 inches. 5 . The microphone assembly of claim 1 , further comprising an internal support structure disposed between at least one filter layer and the sleeve.

6. The microphone assembly of claim 1, further comprising an outer frame disposed outside the outer support structure, the outer frame being configured to provide additional protection for the transducer chamber.

7. The microphone assembly according to claim 1, wherein: The porosity of the outer support structure ranges from about ten pores per square inch (10 PPI) to about forty-five pores per square inch (45 PPI).

8. The microphone assembly of claim 1, wherein: The outer surface of the transducer chamber includes a ring along a circumference of the transducer chamber, and wherein the sleeve fits over the surface of the ring to form a seal between the transducer chamber and the sleeve.

9. A particle filtering system for a microphone assembly, comprising: External support structure; at least one filter layer, the at least one filter layer being contained by the outer support structure, wherein the at least one filter layer comprises at least one item from the group consisting of: at least one layer of electrostatic media filter, at least one layer of activated carbon filter, and at least one layer of nonwoven fabric filter, the at least one filter layer being configured to filter particles from entering the transducer chamber; and a sleeve disposed between the at least one filter layer and the transducer chamber, the sleeve being configured to retain the at least one filter layer and prevent the at least one filter layer from sliding from the transducer chamber, wherein the at least one filter layer provides a minimum efficiency reporting value (MERV) rating of greater than or equal to thirteen (13), and the filter layer captures at least fifty percent (50%) of particles between 0.3 μm and 1 μm, greater than or equal to approximately eighty-five percent (85%) of particles between 1 μm and 3 μm, and greater than or equal to approximately ninety percent (90%) of particles between 3 μm and 10 μm.

10. The particle filtration system according to claim 9, wherein: The outer support structure has a porosity of less than or equal to about fifty-five pores per square inch (55 PPI).

11. The particle filtration system according to claim 10, wherein: The outer support structure has a porosity of about ten pores per square inch (10 PPI) to about forty-five pores per square inch (45 PPI).

12. The particle filtration system according to claim 9, wherein: The at least one layer of electrostatic media filter includes electrostatically charged synthetic fibers.

13. The particle filtration system according to claim 9, wherein: The at least one layer of nonwoven fabric filter comprises an engineered fabric having a random arrangement of filaments or fabrics, wherein the nonwoven fabric filter is at least one of the following group, the group consisting of: meltblown nonwoven media filters and spunbond nonwoven media filters.

14. The particle filtration system according to claim 9, wherein: The at least one filter layer has a thickness between about 0.1 inches and about 0.5 inches.

15. The particulate filtration system of claim 9, further comprising an internal support structure disposed between the at least one filter layer and the sleeve.

16. The particle filtration system according to claim 9, wherein: The sleeve is a removable sleeve.

17. The particle filtration system of claim 9, further comprising an outer frame disposed outside the outer support structure, the outer frame configured to provide additional protection for the transducer chamber.

18. The particle filtration system according to claim 9, wherein: The outer surface of the transducer chamber includes a ring along a circumference of the transducer chamber, and wherein the sleeve fits over the surface of the ring to form a seal between the transducer chamber and the sleeve.

19. A particle filtering system for a microphone assembly, comprising: a filter layer configured to filter particles from entering the transducer chamber; as well as a sleeve disposed between the at least one filter layer and the transducer chamber, the sleeve being configured to retain the filter layer and prevent the filter layer from sliding from the transducer chamber, wherein the filter layer provides a minimum efficiency reporting value (MERV) rating of greater than or equal to thirteen (13), and the filter layer captures at least fifty percent (50%) of particles between 0.3 μm and 1 μm, greater than or equal to approximately eighty-five percent (85%) of particles between 1 μm and 3 μm, and greater than or equal to approximately ninety percent (90%) of particles between 3 μm and 10 μm.

20. The microphone assembly of claim 19, wherein: The filter layers include at least one electrostatic medium filter, at least one activated carbon filter and at least one nonwoven fabric filter.

Images