Patent Application
20190130882
The present invention relates to the field of music creation and musical instruments. More particularly the invention relates to generating sounds from a musical instrument without direct contact between a musician and the musical instrument.
Typical musical instruments are designed to be played by a musician through direct physical contact of the musician with some part of the instrument. Attempts to create instruments that do not require direct contact of the musician have generally been approached from either a) mechanical actuators, or robotics, replacing the hands and/or feet of a musician and attempting to replicate the motions of the musician or b) electronic instruments which may be played by control signals from either a computing device or a control surface, such as a keyboard, played by a musician. In the first case, the musical instruments are commonly acoustic instruments and the robotics, which are activated by control signals or mechanical controls, act as the musician, producing sound from the instrument in the same manner as if a human musician were playing the instrument. In the second case, the sound is created electronically and must be converted to an audible sound using an amplifier and loudspeaker.
Some musical instruments are available in two forms: acoustic instruments and electric instruments. Acoustic instruments can be played and heard by an audience without the need for amplification or loudspeaker. An example would be an acoustic piano, which can be heard in a room without any form of electronic amplification. Electric instruments generally require some form of electronic amplification and loudspeaker to be heard by an audience and have an output jack which sends an electrical signal to amplifiers, processing electronics or recording devices. An example would be an electric piano or synthesizer which would require an electronic amplifier and loudspeaker to be heard. Musicians choose acoustic or electric instruments based on the desired sound and application and often will switch back and forth between them based on the song being performed to employ the different sounds.
An acoustic instrument creates an audible sound by the creation of vibrations within the instrument which are generated by the actions of the musician. The vibrations excited within the instrument by the musician are affected by the physical form of the instrument, which serves to excite corresponding vibrations in the air surrounding the instrument. The vibrations of the air around the instrument are carried as sound waves through the air to the ear of the listener. An acoustic instrument generally has a different sound characteristic than its electric counterpart, mainly due to the construction of the body of the instrument, which has a significant impact on the overall sound. Body characteristics, materials, and construction methods that make for a good acoustic instrument are generally quite different than those that make for a good electric instrument.
An electric instrument generates an analog electrical signal in response to the actions of a musician. This signal is sent to an electronic amplifier, which drives a loudspeaker to create sound waves which can travel through the air to the ear of the listener.
Many instruments are available in either acoustic or electric form and some are available in a combined form. One such combined form is the inclusion of an electric sensor or microphone in an acoustic instrument, such as an acoustic guitar, so the instrument may be used as an acoustic instrument or the electrical output may be plugged into other electronics, such as an electronic amplifier. Attempts to provide an acoustic sound from an electric instrument have been attempted by inclusion of a mechanical sensor in an electric instrument to pick up the mechanical vibrations in the instrument and convert them to an electrical output signal. The acoustic properties of the electric instrument are vastly different from those of the acoustic instrument, so these combined form instruments frequently result in a reduction in the sound quality of the electric sound, the acoustic sound, or both.
One problem encountered by musicians is the inability to easily switch back and forth between the acoustic instrument sound and the electric instrument sound in the same performance. In the case of an instrument that is held in the hands as it is played such as guitar, violin, saxophone, etc., the musician must put down or let go of one instrument, for example an acoustic guitar, before playing another, for example an electric guitar. This can interfere with a performance because the musician must stop playing for a period of time while changing instruments. The combined form of an electric and acoustic instrument mentioned earlier is an attempt to improve this situation, but as mentioned previously the body of the instrument greatly affects the sound and the combined form usually results in inferior sound from either the acoustic instrument sound or the electric instrument sound from these combined instruments.
Another problem faced by musicians is that generally only one instrument may be played at a time. If a musician had the capability of having one performance generate sound from multiple instruments, the overall sound could be much fuller and richer. Electronic synthesizers often have the capability of generating multiple sounds from a single performance, but other traditional instruments do not.
Another problem encountered with the existing state of musical instruments is that there is no way to exactly repeat a performance using a different instrument. If a musician plays and records a piece of music perfectly on an electric guitar, for example, and then later decides it would sound better on an acoustic guitar, the entire performance must be repeated and recorded using the acoustic guitar, which can take significant time due to the chance for mistakes.
Yet another shortcoming of the existing art in musical instruments is that all instruments must be available to the musician at the time of the performance. There is a standard called Musical Instrument Digital Interchange (MIDI) which provides for the recording of certain performance information which can then be used to trigger sounds from a synthesizer at a later time, but the standard does not include provisions, method or any mechanism for generating sounds from a real instrument.
What is needed is a way to enable the playing of a musical instrument without the musician having to physically touch it so the musician may “play” multiple instruments at the same, switch back and forth between different instruments without having to stop playing, use a previously recorded signal to play a musical instrument, or play an instrument in a remote location.
Disclosed is a system and method for remotely generating sound from a musical instrument. In one embodiment, the system includes an input configured to receive a signal representative of the sound of a first musical instrument, an exciter for converting the signal to mechanical vibrations, and a coupling interface for coupling the mechanical vibrations into a second musical instrument. The externally generated signal from the first musical instrument is generally an analog electrical signal carried on a wire or wires.
An object of the disclosed system is to provide a device for remotely generating sound from a musical instrument.
Yet another object of the disclosed system is to provide a device which can accept an input signal, convert the input signal into vibrations, and couple the vibrations into a musical instrument, producing a sound different from that of the original input signal.
An object of the disclosed method is to provide a method for playing a musical instrument without physically touching it. Disclosed is a method which allows generation of sound in a musical instrument from a remote signal, without requiring physical contact between a musician and the instrument.
Another object of the disclosed system is to provide a device which can be easily attached to or removed from an acoustic instrument.
Another object of the disclosed system is to provide a system which can be calibrated, taking into account the response of an acoustic instrument to which the system is mounted.
The disclosed system comprises a system and method for using a signal to excite vibrations in a musical instrument without a musician having to physically touch the instrument. By exciting vibrations at the correct location(s) in the instrument, the overall sound characteristic of the instrument is maintained even though a musician is not playing the instrument in the traditional manner.
In one embodiment, the disclosed system provides an input for receiving an externally generated signal, an exciter for creating vibrations, and a coupling interface for coupling the vibrations into a musical instrument. In an embodiment, the externally generated signal is an analog electrical signal carried on a wire or wires.
The disclosed system provides a significant improvement in the amount of flexibility afforded the musician during performance by allowing the musician to get sound from a second instrument while playing a first instrument, without having to stop playing the first instrument.
Another benefit of the disclosed system is that it allows an instrument to be played which is remotely located. A signal may be transmitted using any available transmission method to another location where the disclosed system is installed and the instrument on which the disclosed system is installed may be played by the remote signal. This would allow for totally new ways of transmitting and receiving live performances. Instruments may be distributed in many different locations, including private homes, with the disclosed system installed. A musician can play a single instrument which would be used to generate the signal to be transmitted to all the distributed disclosed systems. Each instrument to which the disclosed system was installed would, upon receiving the signal, sound as if the musician were in the room playing that particular instrument.
The disclosed system may also be used to allow an instrument to be played at a different time than the original performance. A recording of a performance may be used as the signal sent to the disclosed system. The recorded signal would “play” the instrument without a musician even being present at the time of playback. This provides a way to play an instrument that is not available to the musician at the time of the original recording or the ability to go back to a recording and change the sound of an instrument by having the recorded signal play a different musical instrument than the one originally recorded.
The disclosed system allows an instrument to be played via a signal generated by another instrument or computer to get a totally different sound that combines the sound characteristic from the original instrument with the sound characteristic of the instrument to which the disclosed system is installed.
The system may be made removable by employing a removable attachment means, including mounting provisions for easily affixing the system to a structure of an acoustic instrument. The removable attachment means may attach to the body, strings, sound hole, or some other structure of the acoustic instrument. The removable attachment means may comprise a clamp, bracket, flange, brace, retaining bar, or other such structure that can be readily attached and detached. In an embodiment for a string instrument, the removable attachment means is configured to attach to a top or soundboard of the acoustic instrument proximate to a sound hole of the string instrument, while positioning the coupling interface to be in contact with a bridge or saddle of the string instrument. In an alternate embodiment, the removable attachment means is configured to secure the system to the strings of a string instrument while positioning the coupling interface to be in contact with a bridge, saddle, or contacting a string or strings directly opposite the point where the string contacts the saddle or bridge.
In an embodiment, a bracket is provided, which spans a sound hole or a portion of the sound hole of an acoustic guitar. The bracket is held in place by a groove along the edges of the bracket, forming a top and bottom lip, which slides onto the sound board at the peripheral edge of the sound hole. The exciter is secured to the bracket by at least one standoff which positions the coupling interface to contact the saddle of the guitar with pressure exerted on the saddle. The vibrations of the exciter travel through the coupling interface through the saddle and into the rest of the guitar. In a variation of this embodiment, the coupling interface contacts the strings of the acoustic guitar at or very near the saddle, imparting vibration through the strings and into the saddle.
In an embodiment for use with an acoustic guitar or bass, the removable attachment means comprises a T-shaped clamping bar having a stem and a cross bar. The stem is attached to the cross bar at one end and includes a distal end away from the cross bar. The cross bar is aligned substantially parallel to the strings and inserted between the center two strings. The cross bar is then rotated ninety degrees (90°) around the axis of the stem to be perpendicular to the strings. The distal end of the stem is pulled away from the strings, drawing the cross bar up tight against the strings, applying tension to the strings and securing the system to the strings. The stem is secured to maintain the tension on the strings. The stem may be secured at the distal end by a cam, threaded fastener, pin, fork, or other locking means. The clamping bar may be made from metal, such as aluminum, brass, steel, or other suitable metal, or may be made from other materials of sufficient strength to apply tension to the strings without breakage or deformation of the clamping bar. A variety of strong plastics or composites, including phenolics, acetals, cellulosics, and other polymers, may be used for the clamping bar. The stem and cross bar may be made from the same material or made from different materials fastened together.
In an embodiment, the system includes response adjustment using at least one transducer for signal feedback and error correction. A microphone and/or vibration transducer is used to sense the acoustic and/or vibration response of the acoustic instrument to which the system is attached and form a feedback signal. The feedback signal is compared to a target response to create an error signal, which is applied to a response corrector to formulate a corrective transfer function which corrects the input signal. The feedback, correction, and processing is implemented using digital signal processing (DSP), however analog processing or a combination of digital and analog processing may be used as well. The DSP includes various predetermined target responses to which the actual response of the acoustic instrument is compared. The DSP alters the transfer function of the response corrector to modify the output signal being applied to the exciter, providing the overall characteristic sound of the target response from the acoustic instrument.
In one embodiment, the response adjustment is self-calibrating, using a predetermined calibration signal to excite vibrations in the acoustic instrument across the audio spectrum. A microphone and/or vibration transducer is used to create a feedback signal representing the physical response of the acoustic instrument to the calibration signal. The feedback signal is then analyzed and compared to a predetermined target response, generating a physical response error signal, which is the difference between the actual response and the target response across the measured spectrum. The physical response error signal is stored in the DSP and the inverse of the physical response error signal is combined with the input signal to create a corrected physical response.
In one embodiment, the response adjustment is performed more than once, either continuously or at regular intervals. In this embodiment, the input signal is analyzed and compared to a predetermined target input signal, generating an input error signal, which is the difference between the actual input signal and the target input signal. The input signal is then modified to create a modified input signal which more closely resembles the target input signal. In an embodiment, this approach is combined with the self-calibrating approach using a physical response feedback signal. The combined approach uses the modified input signal to compensate for variations in input signal and the calibration signal, physical response feedback signal, and physical response error signal to compensate for the physical response of the acoustic instrument.
The signal processing used in the response adjustment may include the stages for audio filtering, dynamics processing, including compression and expansion, and gain adjustment, however not all stages will be necessary for all acoustic instruments. Optionally, additional processing stages may be included as well, such as variable delay processing, time alignment, phase correction, etc.
The vibration transducer used for mechanical feedback during response adjustment may be incorporated into the acoustic instrument, may be attached to the acoustic instrument separately from the exciter, or may be integrated into the exciter housing in a manner that provides contact with the body of the acoustic instrument when the exciter is properly installed on the acoustic instrument. Likewise, the microphone used for acoustic feedback during response adjustment may be incorporated into the acoustic instrument, mounted to the acoustic instrument separately from the exciter, or may be integrated into the exciter housing.
In the following description of one embodiment, reference is made to the included drawings which form a part of this specification and are included to illustrate specific embodiments of how the disclosed system may be practiced. It should be understood by the reader that structural changes may be made without departing from the scope of the disclosed system. It should also be understood that the embodiment(s) illustrated is not intended to limit the scope of the disclosed system and the inventor anticipates changes in the structure and form of the disclosed system to properly adapt to the physical form of different musical instruments.
A signal 107 is generated, by a first musical instrument, by a recording of a first musical instrument, or by other method, which represents the sound of a first musical instrument. Signal 107 is typically an analog electrical signal produced by an electric instrument, such as an electric guitar.
The system is installed on a physical object, such as a second musical instrument.
The signal 107 is fed to the input 101 of the system, optionally passing through a switching system 106 and/or a signal conditioning element 104.
The input 101 receives the signal 107, which may be transmitted from the source in a variety of ways including, but not limited to, a wire, optically, RF waves or other wireless transmission methods. Signal transmission systems and methods are well known in the art for carrying electrical, optical, acoustic, and radio frequency signals. The input 101 may comprise a jack, a plug, a hard-wired connection, a wireless connection, or other device for receiving the signal 107. If required, the input 101 converts the received signal to an electrical signal.
The exciter 102 accepts the electrical signal from the input 101 and converts it to mechanical vibrations. Transducers to convert electrical signals to mechanical vibrations are well known in the art and many of the different types may be employed in the practice of the disclosed system including, but not limited to, solenoids, linear actuators, piezoelectric transducers, and electromagnetic actuators. An electromagnetic transducer based on a fixed permanent magnet and a moving coil of wire mounted to a former is well known in the art and may be employed as the exciter in the practice of the disclosed system. The range of human hearing is normally taken to be 20 Hertz to 20,000 Hertz but musical instruments often have a frequency range significantly less than the full range of human hearing. Optimally, the exciter 102 would be capable of exciting all frequencies of vibration that the acoustic instrument could normally reproduce. However, the exciter 102 may be effectively employed to reproduce a subset of those frequencies where the frequencies of vibration would not normally be heard, the input signal 107 is of limited bandwidth, or certain frequencies are not desired for a particular sound or special effect.
The coupling interface 103 provides a way to transfer the vibrations from the exciter 102 to the target instrument. Optimally, the coupling interface 103 would include mounting provisions for keeping the disclosed system in contact with the target instrument for effective transmission of the mechanical vibrations from the exciter 102 to the instrument. The vibrations may be coupled through direct contact of some portion of the exciter 102 to some portion of the instrument, or they may be coupled through an additional element or elements. In one embodiment, the mechanical actuator is integrated directly into the structure of the musical instrument to directly couple the vibrations into the structure of the instrument. In this embodiment, the coupling interface 103 would be the direct contact of at least some portion of the exciter 102 to some portion of the instrument structure. In other embodiments, the coupling interface 103 may take the form of a mounting bracket, adapter, clamp, adhesive, or other forms or materials which direct the vibrations formed by the exciter 102 into the instrument. The coupling interface 103, as well as mounting provisions, may be integrated into the housing of the exciter and still be within the scope of the disclosed system. The only requirement for the coupling interface 103 is that there be a manner in which the vibrations from the exciter can be transferred to the target instrument. In one embodiment, the coupling interface 103 would take the form of an adapter configured to mount the exciter in the optimum location on a target instrument, however the coupling interface 103 need not embody a separate physical component.
An optional signal conditioning element 104 may be placed anywhere in the signal path to modify the signal 107 prior to the signal getting to the exciter 102. The signal conditioning element 104 may comprise one or more active or passive electrical circuits. This may be done to emphasize or de-emphasize certain frequencies to achieve a better overall sound. It may also be done to change the amplitude of the signal 107, add special affects, or provide other signal transformations as are well known in the art of music electronics. Signal conditioning of musical instrument signals is well known in the art and includes many effects such as chorus, reverberation, time delay, phase shifting, amplitude modulation, frequency modulation, distortion, overdrive, spectral modifications, equalization and others.
The disclosed system may be practiced in such a manner that no power other than the input signal 107 is required if the input signal 107 can be ensured to be large enough to drive the exciter 102 directly. In cases where this is impractical, for example when the input signal 107 is transmitted to the input 101 via a wireless connection, a power supply 105 and signal amplifier 108 would be added to the system to generate a strong enough signal to drive the exciter. The power supply 105 may get power from an AC power cord 109 or via a battery (not shown) or other power storage device (not shown). Power supplies and amplifiers are well known in the art.
The disclosed system may be further extended in usability by inclusion of an optional switching system 106 which provides for easily directing the signal 107 from a musician's instrument to either the disclosed system input 101 or to another device's input. As an example, if the musician is playing an electric guitar and the disclosed system is mounted on an acoustic guitar, the optional switching system 106 would allow the musician to have the output from his electric guitar routed to an amplifier to reproduce the electric guitar sound, or to the disclosed system to play the acoustic guitar sound.
The system may be, but need not be, housed in a single housing. Partitioning the system into multiple assemblies can provide flexibility in application and allow for size reductions of the individual components. In some applications it may be preferable to have the exciter and coupling interface integrated into an adapter configured for easy mounting to the target instrument, with some or all of the electronics located in another housing away from the exciter and coupling interface. This would reduce the weight, size, and complexity of the exciter and coupling interface assembly. In one embodiment, the input, all electronics and a switching system would be housed in a first housing, while the exciter and coupling interface would be included in an assembly configured to mount to a target musical instrument. In an embodiment, all system components are housed together in a single structure, forming a device which may be easily installed to or removed from an acoustic instrument, although certain components, such as the coupling interface or input connector, may need to protrude through the housing.
An embodiment adapted for use on an acoustic guitar will be now described to illustrate one embodiment. A common acoustic guitar shown in
The second set of mechanical vibrations in the body of the acoustic instrument 505 are sensed by vibration transducer 506, producing a first feedback signal F1, 512, which is applied to processing block 513. Processing block 513 provides signal conditioning for signal F1, 512 according to fixed transfer function H1. The conditioned signal 514 is applied to a first input of Digital Signal Processor (DSP) 530 and optionally routed to an additional processing block 515, which may provide a fixed or variable transfer function H3, creating mechanical feedback signal 516, which is sent to comparator 518. Transfer function H3 may be modified by a weighting factor K3. A mechanical target response (MTR) signal 526 is sent to comparator 518 and compared to mechanical feedback signal 516 to create mechanical error signal e1, 517. Mechanical target response signal 526 is synchronized to signal generator 528 to match the system mechanical response and corresponding error signal e1, 517 with calibration signal 509.
Acoustic output 532 from acoustic instrument 505 is sensed by microphone 511, producing a second feedback signal F2, 519, which is applied to processing block 520. Processing block 520 provides signal conditioning for signal F2, 519, according to fixed transfer function H2. The conditioned signal 521 is applied to a second input of DSP 530 and optionally routed to an additional processing block 522, which may provide a fixed or variable transfer function H4, creating acoustic feedback signal 523, which is sent to comparator 524. Transfer function H4 may be modified by a weighting factor K4. An acoustic target response (ATR) signal 527 is sent to comparator 524 and compared to acoustic feedback signal 523 to create acoustic error signal e2,525. Acoustic target response signal 526 is synchronized to signal generator 528 to match the system acoustic response, and corresponding error signal e2, 525 with calibration signal 509.
Error signal e1, 517 is analyzed by processing block 529 to determine the variation between the expected mechanical target response and the measured mechanical target response. Similarly, error signal e2, 525 is analyzed by processing block 529 to determine the variation between the expected acoustic target response and the measured acoustic response. The error signals 517 and 525 may also be analyzed relative to each other to determine the how the mechanical response corresponds to the acoustic response for a given acoustic instrument 505. Weighting factors K3 and K4 may be adjusted to set the relative influence of their respective error signals on the compensation processing. Either error signal may be temporarily or permanently eliminated from affecting the compensation by setting its respective weighting factor K3 or K4 to zero. Based on the analyses and compensation processing, a corrective transfer function is computed to compensate for the errors. The simplest form of the corrective transfer function is the inverse of the sum of the error signals, such that:
So=Si(1/e1+e2)
The corrective transfer function is loaded into processing block 504, replacing the original G(s) with a new G(s) to provide corrective processing. Calibration can be considered complete, or the process may be run one or more additional times to fine tune G(s) for best error correction. Once the calibration process is complete, switch 531 is switched to permit an external input signal SE,507 to route through the system components 501, 504, 502 and 503 to generate acoustic output 532 from acoustic instrument 505. Transfer function G(s) is stored in memory so calibration does not need to be repeated every time the system is used.
Different target transfer functions for MTR and ATR may be stored to provide different corrected outputs, thereby providing a number of different acoustic responses. This allows the response to be set for different types of acoustic instruments or to product different acoustic responses from a single instrument.
In an embodiment, first feedback signal 512 or second feed signal 519 is eliminated, along with the respective processing and target response signals, providing a system with a single feedback loop for determining the corrective transfer function G(s) of processing block 504.
In an embodiment, input 501 is routed directly to an input of DSP 530, with the functions of switch 531 and processing block 504 incorporated into DSP 530. In an embodiment, processing block 513 and/or processing block 520 are incorporated into DSP 530.
The linear electromechanical transducer 608 may also be configured such that the application of a voltage to the transducer causes an element of the transducer to change at least one of its physical dimensions, thereby exerting force on any object the transducer is attached to.
Linear exciter 608 is configured to be roughly the shape of an internal brace 602b of the guitar and is installed on soundboard 601 inside the guitar. As shown in
The disclosed system may be adapted to instruments other than string instruments. For example, brass instruments may be made to work with the disclosed system using a coupling element adapted to attach at the mouthpiece of the instrument. Other instruments may be adapted by considering their primary mode of sound generation and constructing a coupling interface that uses the vibrations created by the exciter to generate vibrations in the instruments in a manner similar to their primary mode of sound generation. A reed instrument, for example, creates sound when air passing over a reed causes vibrations of the reed. By considering this primary mode of sound generation, one skilled in the art would understand that a coupling interface could be constructed to impart vibrations into the reed instrument in nearly the same location that the reed would normally be located. The vibrations from the disclosed system would then couple into the instrument in a manner substantially similar to the manner in which the vibrations from the reed couple into the instrument. This approach may used to determine the proper construction of the coupling interface for other instruments.
Some applications will benefit from the use of two or more exciters and the use of two or more coupling interfaces. This may be done to extend the frequency response of the system by having multiple exciters reproduce all or a subset of the frequencies from the overall desired frequency response. Multiple exciters or multiple coupling interfaces will also be useful to more accurately direct vibrations into certain parts of a musical instrument. An example would be a string instrument with multiple saddles having an exciter and coupling interface for each saddle. It would also be useful in some instruments to use one or more exciters and/or one or more coupling interfaces at the primary region of sound generation for the instrument combined with one or more exciters and/or one or more coupling interfaces in other locations on the instrument to reinforce the vibrations in the instrument, thereby providing a louder sound or an altered frequency response from the instrument.
It is also possible to use the disclosed system to excite an instrument in a manner different from its primary mode of sound generation. This may be done to create new sounds from the instrument or to affect the spectral characteristics of the sound from an instrument. Additionally the disclosed system may even be fed an input signal generated by the instrument itself in the normal manner of playing the instrument to alter the sound or performance of the instrument. As an example, the primary mode of sound generation in a brass instrument is the vibration of the lips of the musician blowing into the mouthpiece. The disclosed system may be attached to another part of the instrument, for example the bell, to get a different sound from the instrument when presented with a signal from either an external source or from the same instrument. If the disclosed system is located at the bell of the instrument, for example, and the musician plays the instrument normally, the disclosed system would then impart different vibrations into the instrument than the normal ones. These two different sources of vibrations would combine within the instrument, creating spectral changes in the sound coming from the instrument thereby generating new sounds not available from the instrument without the use of the disclosed system. This same approach may be applied to other musical instruments.
This application is a continuation application of pending U.S. patent application Ser. No. 15/413,376 which is a divisional application of patent application Ser. No. 14/215,066, issued on Mar. 7, 2017 as U.S. Pat. No. 9,589,555, which claims priority to U.S. provisional application 61/794,488, filed Mar. 15, 2013 and to U.S. patent application Ser. No. 13/681,319, filed Nov. 19, 2012 and issued on Apr. 5, 2016 as U.S. Pat. No. 9,305,533, which in turn claims priority to U.S. patent application Ser. No. 11/619,212, filed on Jan. 3, 2007 and issued on Nov. 20, 2012 as U.S. Pat. No. 8,314,322, each of which listed prior application is hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61794488 | Mar 2013 | US |
| Number | Date | Country | |
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| Parent | 14215066 | Mar 2014 | US |
| Child | 15413376 | US |
| Number | Date | Country | |
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| Parent | 15413376 | Jan 2017 | US |
| Child | 16231536 | US | |
| Parent | 11619212 | Jan 2007 | US |
| Child | 13681319 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13681319 | Nov 2012 | US |
| Child | 14215066 | US |
