Patent Publication Number: US-2023156385-A1

Title: Microphone system and methods

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to the field of microphones, and more particularly to a microphone system and methods for selectively routing audio signals. 
     BACKGROUND 
     Microphones, such as directional microphones, are widely used in various applications such as news gathering, sporting events, outdoor film recording, and outdoor video recording. Once audio is captured, it can be output to one or more devices via a wireless or wired connection. 
     Wired microphones typically include an audio interface for outputting the audio to another device. For example, conventional microphones may include an optical interface, a high definition multimedia interface (HDMI), a universal serial bus (USB), a three-pin external line return (XLR), a tip and sleeve (TS) connector, a tip, ring, and sleeve (TRS) connector, and the like. 
     To accommodate for the variety of audio connectors in the market, certain microphones may include a plurality of analog and/or digital interfaces. However, such microphones are typically configured to output audio via only one interface at a time, such that the remaining interfaces are inoperable. Microphones with a number of interfaces also may require a user to manually select the interface through which audio is output. Moreover, wired microphones that utilize an analog input often rely on the host device to enhance the sound and performance of the audio. 
     Conventional microphones typically require a battery to store and provide power. When the battery is low or out of power, charging the battery is required to allow continued usage. In addition, if the user wishes to output audio through a wireless connection, such connection may be impossible to perform when the battery of the microphone is depleted and thereby renders the microphone nonfunctional. 
     Therefore, there is a need for a microphone that is configured to selectively route audio signals to each available interface for improved functionality over traditional prior art microphones. The present invention satisfies this need. 
     SUMMARY 
     The present invention relates generally to the field of microphones, and more particularly to a microphone system and methods for selectively routing audio signals to one or more ports for output. 
     In one aspect, the microphone may operate in a default configuration. In the default configuration, a capsule of the microphone may be directly connected to an analog port, such as a 3.5 mm TRS connector. A host device may connect via the analog port such that power is provided to the capsule from the host device and an audio signal is directly routed from the capsule to the host device. For example, the power provided to the capsule may be a standard 2-5 volt DC power that most cameras and computing devices with a 3.5 mm input provide as a biasing voltage for small microphone capsules and other peripherals. 
     In another aspect, the microphone may be configured to switch from the default configuration in response to detecting a connection via a digital port of the microphone. When a host device, such as a computer, tablet or mobile device, is connected via a digital port, the microphone may operate as a USB microphone. In other words, USB circuitry of the microphone may be powered and audio signals may be routed through the digital port to the host device digitally. 
     In addition, when switched from the default configuration, the analog port may be used as a headphone output, which may facilitate providing enhanced audio. For example, the audio routed from the microphone to the host device may be amplified through processing circuitry to provide a high-level output to a user. As a result of switching from the default configuration, the microphone may facilitate both inputting and outputting audio signals to, for example, provide audio recording along with two-way communications, such through internet-based applications including Zoom, Microsoft Teams, Skype, and the like. 
     In yet another aspect, audio signals may be selectively routed via a switching circuit of the microphone. Switching circuitry may include one or more semiconductor switches, such as a Complementary Metal Oxide-Semiconductor (CMOS), that are configured to normally closed (i.e., in a default configuration) when no connection is made via the digital port. 
     When switching circuitry is in the normally closed position, audio signals may be routed from the capsule directly to a second switch. The second switch may also be normally closed such that audio signals pass directly to the analog port. In other words, when both switches are in a normally closed position, the microphone capsule is configured to receive power via the analog port, and audio signals from the capsule are routed directly to the analog port for output to the host device. 
     In response to detecting a connection via a digital port, switching circuitry may change to a normally open position. In the normally open position, audio signals from the capsule are routed to processing circuitry, which may include an analog-to-digital converter, a digital-to-analog converter, a digital signal processor, and other audio signal processing circuitry. Once processed, a digital audio signal may be routed to the host device via the digital port. In addition, the audio signal may be routed to the second switch and through to the analog port, which may output audio from the microphone or from the host device to a headphone. 
     It yet a further aspect, when switching circuitry is in a normally open position, since the capsule is no longer connected directly to the second switch, a separate capsule biasing voltage may be generated and applied directly to the capsule as there is no plugin-power present. Moreover, the processing circuitry also may include a microprocessor for audio signal processing to enhance the sound and performance of the microphone when connected to a host device via the digital port. 
     While the invention is susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawings and have herein been described in detail. It should be understood, however, that there is no intent to limit the invention to the particular embodiments disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments are illustrated by way of example and not limitation in the figures in the accompanying drawings, in which like references indicate similar elements and in which: 
         FIG.  1    illustrates a front perspective view of an exemplary microphone; 
         FIG.  2    illustrates a rear perspective view of the microphone of  FIG.  1   ; 
         FIG.  3    illustrates a side view of the microphone of  FIG.  1    including a digital port; 
         FIG.  4    illustrates a side view of the microphone of  FIG.  1    including an analog port; 
         FIG.  5    illustrates an exploded view of the microphone of  FIG.  1   ; 
         FIG.  6    illustrates a perspective view of the microphone of  FIG.  1    and an exemplary environment; 
         FIGS.  7 A- 7 D  illustrate an exemplary microphone circuit configuration; and 
         FIG.  8    is a flowchart illustrating an exemplary operation for selectively routing an audio signal. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention relates generally to the field of microphones, and more particularly to a microphone including an analog port and a digital port through which audio may be output. The microphone may be configured to obtain power from a host device and may include circuitry for selectively routing audio signals to the one or more ports. Advantageously, the microphone may be configured to connect with a variety of host devices and may facilitate functioning as a USB microphone via the digital port, while the analog port may be used as a powerful headphone output 
     Turning now to the drawings wherein like numerals represent like components,  FIGS.  1 - 5    illustrate an exemplary microphone  100 . As shown, microphone  100  has a body  102 , a front cap  104 , and a rear cap  106 . Body  102  and front cap  104  may include one or more openings  108  to permit sound waves to enter. While body  102  is shown to be substantially tubular, other shapes are contemplated. 
     Although microphone  100  is not limited to specific dimensions, the length of body  102  may range between about one hundred millimeters and about two hundred millimeters and preferably between about one hundred and fifty millimeters and about one hundred and eighty millimeters. In one embodiment, body  102  is about one hundred and seventy millimeters in length. The diameter of body  102  may range between about ten millimeters and about thirty millimeters and preferably between about fifteen millimeters and about twenty five millimeters. In one embodiment, the diameter of body  102  is about twenty one millimeters. 
     As shown in  FIGS.  1 - 4   , body  102  of microphone may include audio connectors. In particular, body  102  may include an analog port  110  and a digital port  112 . Analog port  110  may include, for example, a tip-sleeve (TS) connector, a tip-ring-sleeve (TSR) connector, a tip-ring-ring-sleeve (TRRS) connector, an RCA connector, an XLR connector, and the like. Preferably, analog port  110  is a 3.5 mm TRS connector. Digital port  112  may include, for example, an RCA connector, a High-Definition Multimedia Interface (HDMI) connector, a DisplayPort connector, and the like. Preferably, digital port connector  112  is a USB or USB-C type connector. 
       FIG.  5    illustrates an exploded view of microphone  100 . As shown, components of microphone  100  may be housed between front cap  104  and rear cap  106  within body  102 . Specifically, microphone  100  may include a front mesh  114 , a line tube foam  116 , side mesh  118 , a spine assembly  120 , a printed circuit board (PCB)  122 , and line tube fabric  124 . 
     Front mesh  114  and side mesh  118  of microphone  100  may be formed of one or more layers, More specifically, the one or more mesh layers may be used to adjust the acoustic impedance properties of microphone  100  and may prevent intrusion of foreign matter and fine particles. Examples of mesh materials that may be used include nonmetallic (e.g., nonconductive) materials such as woven polyester and PVC-on-polyester fabrics or metallic materials such as stainless steel. In general, mesh material may be formed from any suitable fabric material that exhibits acceptable acoustic performance, such as for example, sound transparency of 90% or more. 
     Line tube foam  116  may include a polyurethane foam, a dense fiber material or other material sufficient to exhibit sound absorbing properties. As shown, microphone  100  may further include line tube fabric  124  to form a protective barrier against a penetration of particles. 
     As show in  FIG.  5   , PCB  122  may be mounted on spine assembly  120 . Spine assembly  120  may include a microphone capsule  126 , such as an electret capsule. Capsule  126  may be configured to convert sound waves into electrical signals. In particular, capsule  126  may include a flexible diaphragm and an insulated electrode referred to as a backplate. The diaphragm and backplate form the two plates of a capacitor, which, in the absence of a sound wave, will have a very small but definite capacitance. When a sound wave displaces the diaphragm, the capacitance will either be increased above or reduced below a resting value; depending upon whether the sound wave pushes the diaphragm toward the backplate or causes it to bow out away from the backplate. 
     Capsule  126  also may include an arrangement of field effect transistors to, for example, achieve low noise. In addition, capsule  126  may be electrically connect to one or more audio interface/port, such as analog port  10  and/or digital port  112 , via PCB  122 . The audio interfaces/ports of PCB  122  may facilitate transmitting audio signals, such as analog or digital frequencies to, for example, a host device such as a camera, computer, table, or mobile device. 
       FIG.  6    illustrates an exemplary system  200  including microphone  100 . As shown, microphone  100  may be coupled with a camera  128  via a mount  130 . Mount  130  may be a suspension shock mount with shoe adaptor  132  for mounting microphone  100  onto camera  128  via a hot/cold shoe  134 . Mount  130  also may include an integrated cable management clip. As illustrates, in an exemplary operation, microphone  100  may connected with camera  128  via a wired connection  129  through, for example, analog port  110 . Once connected, capsule  126  of microphone  100  may be powered (such as via a 2-5V DC power that most cameras provide) and output an audio signal to camera  128  through analog port  110 , as detailed below. 
       FIGS.  7 A- 7 D  illustrates an exemplary circuit  200  of microphone  100 . Circuit  200  may include one or more semiconductors, such as a Complementary Metal Oxide-Semiconductor (CMOS). As shown, circuit  200  may includes a first switching circuit  202  and a second switching circuit  204 . In addition, circuit  200  may include a USB connector  206 , processing circuitry  208  including a codec  210 , thin film resistors  212 , a power supply  214 , and a programming header  216 . 
     As illustrated in  FIG.  7 A , both switching circuits  202 ,  204  may be, by default, in a normally closed (“NC”) configuration  203 . This default configuration  203  corresponds to connection of microphone  100  to a host device via analog port  110 , which may be a 3.5 mm TRS port. Specifically, in the default configuration, capsule  126  of microphone  100  may be powered by “plug-in power,” which may be a standard 2-5 volt DC power that is provided from the host device to microphone  100  through, for example, a 3.5 mm input as a biasing voltage. 
     As shown in  FIG.  7 A , when switching circuits  202 ,  204  are in a normally closed configuration  203 , circuit  200  is configured to route an audio signal directly from capsule  126  to analog port  110 . In other words, in the default configuration, power is passed from the host device through the analog port  110  directly to the capsule  126 , and an audio signal is passed back from the capsule  126  to the host device via the analog port. 
     Upon detecting that microphone  100  is connected to a host device via digital port  112 , such as UBS connector  206  ( FIG.  7 D ), the state of first switching circuit  202  and second switching circuit  204  may be changed from the default configuration  203  (i.e., normally closed) to a normally open (“NO”) configuration  205 . In the normally open configuration  205 , a separate capsule biasing voltage may be generated and applied directly to the capsule as there is no plugin-power present. In addition, in the normally open configuration  205 , audio signals are routed from capsule  126  to processing circuitry  208 . As shown in  FIG.  7 B , processing circuitry  208  may include a codec  210  configured to process an audio signal. Codec  210  may include a digital signal processor (DSP) and an analog-to-digital (ADC) and digital-to-analog (DAC) converters. 
     Moreover, in the normally open configuration  205 , once an audio signal is processed via codec  210 , circuit  200  is configured to route the processed audio signal through digital port  112  (e.g., USB connector  206 ) to the host device. In addition, in the normally open configuration, the analog port  110  may be configured to output audio to another device, such as a headphone. In other words, microphone  100  may be configured to simultaneously output an audio signal via the analog port  110  to a headphone and via the digital port  112  to a host device. In the normally open configuration  205 , analog port  110  may output a processed audio signal from the processing circuit  208  to, for example, provide a high-level output for a used as compared to a direct audio signal from capsule  126 . 
       FIG.  8    is a flowchart  300  illustrating the steps of an exemplary operation of microphone  100 . The operation begins and, in step  302 , microphone  100  detects a connection with a host device, such as a camera, computer, mobile device, and the like. In decision step  304 , microphone  100  will determine whether the connection is through a digital port  112 , such as a USB. 
     If at decision step  304 , the connection is not through digital port  112 , in step  306 , capsule  126  of microphone  100  will obtain power from the host device via analog port  110 . In step  308 , capsule  126  is configured to receive audio and, in step  310 , the audio will be routed directly to analog port  110 . 
     If at decision step  304 , the connection is through digital port  112 , in step  312 , a biasing voltage is generated and applied to capsule  126 . In step  314 , capsule  126  is configured to receive audio. In step  316 , the audio is routed to processing circuitry  208  to enhance the sound and performance of the audio. In step  318 , microphone  100  is configured to output the processed audio via digital port  112 . 
     In decision step  320 , microphone  100  will determine whether there is a connection via analog port  110 . If yes, in step  322 , microphone also may output audio via analog port  110  to, for example, a headphone. The audio output via analog port  110  may be processed and/or enhanced by processing circuitry  208  of microphone  100  or by the host device. For example, microphone  100  may be configured to simultaneously output audio to a headphone and to a camera. 
     Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described in the application are to be taken as examples of embodiments. Components may be substituted for those illustrated and described in the application, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described in the application without departing from the spirit and scope of the invention as described in the following claims.