Abstract
Active noise control (ANC), including active and adaptive noise cancellation (ANC) with non-voice-coil transducers having highly linear transfer functions, such as planar transducers, planar magnetic transducers, electro-static transducers, and piezo-electric transducers. This active and adaptive noise cancellation (ANC) may be used with: planar transducer headphones and earphones; open-backed and closed-back headphones and earphones; in-ear earphones, and phase plugs.
Claims
1. An audio device comprising: an active noise control (ANC) system including an input for receiving an audio source signal, at least one microphone input for receiving microphone signals, and an output for providing a corrected audio signal; at least one microphone connected to the at least one microphone input; and a transducer including an input for receiving the corrected audio signal from the ANC system and an output for providing output sound waves, such that the transducer is a non-voice-coil transducer, and wherein the transducer further comprises a diaphragm including an electro-mechanical system for converting the input into the output for providing sound waves, and a mechano-electrical system coupled to the diaphragm having a mechano-electrical output such that motion of sound waves impacting the diaphragm generates a proportionate mechano-electrical output signal, wherein the mechano-electrical system acts as the at least one microphone connected to the at least one microphone input.
2. The audio device of claim 1 wherein the transducer is a non-cone transducer.
3. The audio device of claim 1 wherein the transducer is a planar transducer.
4. The audio device of claim 1 wherein the transducer is a planar magnetic transducer.
5. The audio device of claim 1 wherein the diaphragm comprises a single diaphragm having a trace pattern with two separate circuits, the diaphragm being disposed in a magnetic field, where the two separate circuits comprise an input circuit disposed on the diaphragm being operative for an input signal from an audio amplifier such that the amplifier current flows through the input circuit trace pattern in the magnetic field which causes the diaphragm to vibrate at audio frequencies in accordance with the input signal, and an output circuit for an output signal generated from the vibrations of the output traces disposed on the diaphragm in the same magnetic field.
6. The audio device of claim 1 wherein the audio device is a hybrid feedforward-feedback audio device, such that the at least one microphone is a feed forward microphone, and the at least one microphone input is a feed forward microphone input.
7. The audio device of claim 1 wherein the active noise control system includes an adaptive noise cancellation system.
8. The audio device of claim 1 wherein the active noise control system includes an analog or digital control system.
9. An audio device comprising: an active noise control (ANC) system including an input for receiving an audio source signal, at least one microphone input for receiving microphone signals, and an output for providing a corrected audio signal; at least one microphone connected to the at least one microphone input; a transducer including an input for receiving the corrected audio signal from the ANC system and an output for providing output sound waves, such that the transducer is a non-voice-coil transducer; and a housing having: a proximal acoustic opening configured for positioning proximal to an ear, and a distal surface located distally from the proximal acoustic opening, wherein the non-voice-coil transducer is disposed in the housing such that the non-voice-coil transducer divides the housing into a proximal cavity between the non-voice-coil transducer and the proximal acoustic opening, and a distal cavity between the non-voice-coil transducer and the distal surface, and at least one microphone disposed in the housing.
10. The audio device of claim 9 such that the proximal cavity includes at least one feedback microphone.
11. The audio device of claim 9 such that the distal cavity includes at least one feed-forward microphone.
12. The audio device of claim 9 such that the distal surface is configured with at least two acoustically transparent openings.
13. The audio device of claim 9 such that the distal cavity contains acoustically absorbent material.
14. The audio device of claim 9 such that the non-voice-coil transducer comprises a planar magnetic transducer.
15. The audio device of claim 9 such that the non-voice-coil transducer comprises an electro-static transducer.
16. The audio device of claim 9 such that the non-voice-coil transducer comprises a piezo-electric transducer.
17. An audio device comprising: an active noise control (ANC) system including an input for receiving an audio source signal, at least one microphone input for receiving microphone signals, and an output for providing a corrected audio signal; at least one microphone connected to the at least one microphone input, a transducer including an input for receiving the corrected audio signal from the ANC system and an output for providing output sound waves, such that the transducer is a planar transducer; a housing having a proximal acoustic opening configured for positioning in an ear canal, and a distal surface located distally from the proximal acoustic opening, the planar transducer disposed in the housing such that the planar transducer divides the housing into a proximal cavity between the planar transducer and the proximal acoustic opening, and a distal cavity between the planar transducer and the distal surface; and at least one microphone disposed in the housing.
18. The audio device of claim 17 such that the proximal cavity includes at least one feedback microphone.
19. The audio device of claim 17 such that the proximal cavity includes a phase plug.
20. The audio device of claim 19 such that the phase plug includes the at least one feedback microphone.
21. The audio device of claim 20 such that the at least one feedback microphone included in the phase plug has an internal microphone opening leading toward the proximal acoustic opening.
22. The audio device of claim 21 such that the internal microphone opening acts as a waveguide toward the proximal acoustic opening.
23. The audio device of claim 17 such that the distal cavity includes at least one feed-forward microphone.
24. The audio device of claim 17 such that the distal surface is configured with at least one acoustically transparent opening.
25. The audio device of claim 17 such that the planar transducer includes a planar magnetic transducer.
26. The audio device of claim 17 such that the planar transducer includes an electro-static transducer.
27. The audio device of claim 17 such that the planar transducer includes a piezo-electric transducer.
Description
DETAILED DESCRIPTION
(1) Boilerplate Here
(2) In the Summary above, in this Detailed Description, in the claims below, and in the accompanying drawings, reference is made to particular features (including method steps). It is to be understood that the disclosure in this specification includes all possible combinations of such particular features. For example, where a particular feature is disclosed in the context of a particular aspect or embodiment, or a particular claim, that feature can also be used, to the extent possible, in combination with and/or in the context of other particular aspects and embodiments.
(3) The term comprises and grammatical equivalents thereof are used herein to mean that other components, ingredients, steps, etc. are optionally present. For example, an article comprising (or which comprises) components A, B, and C can consist of (i.e., contain only) components A, B, and C, or can contain not only components A, B, and C but also one or more other components. Where reference is made herein to a method comprising two or more defined steps, the defined steps can be carried out in any order or simultaneously (except where the context excludes that possibility), and the method can include one or more other steps which are carried out before any of the defined steps, between two of the defined steps, or after all the defined steps (except where the context excludes that possibility).
(4) The term at least followed by a number is used herein to denote the start of a range beginning with that number (which may be a range having an upper limit or no upper limit, depending on the variable being defined). For example, at least 1 means 1 or more than 1. The term at most followed by a number is used herein to denote the end of a range ending with that number (which may be a range having 1 or 0 as its lower limit, or a range having no lower limit, depending upon the variable being defined). For example, at most 4 means 4 or less than 4, and at most 40% means 40% or less than 40%. When, in this specification, a range is given as (a first number) to (a second number) or (a first number)-(a second number), this means a range whose lower limit is the first number and whose upper limit is the second number. For example, 25 to 100 mm means a range whose lower limit is 25 mm, and whose upper limit is 100 mm.
(5) Traditionally acoustic devices are comprised of a housing and a transducer or driver disposed in, on, behind, or in some way coupled or affixed to the housing. Traditionally the housing is relatively stationary, while a moving component in the transducer transforms energy (usually electrical) into sound.
(6) FIG. 1 is an exemplary functional or illustrative schematic view of Audio Device (100) with Active Noise Control System (ANC) (340) including Active and/or Adaptive Noise Control with Audio Source Input (352), ANC Output (362), At Least One Microphone input (312, 322), At Least One Microphone (310, 320), and a Non-Voice-Coil Transducer (90).
(7) FIG. 2 is an exemplary functional or illustrative schematic view of Audio Device 100 with Active Noise Control System (ANC) (340) including Active and/or Adaptive Noise Control with Audio Source Input (352), ANC Output (362), At Least One Microphone input (312, 322), At Least One Microphone (310, 320), and a Non-Cone Transducer (90).
(8) FIG. 3 is an exemplary functional or illustrative schematic view of Audio Device (100) with Active Noise Control System (ANC) (340) including Active and/or Adaptive Noise Control with Audio Source Input (352), ANC Output (362), At Least One Microphone Input (312, 322), At Least One Microphone (310, 320), and a Planar Transducer (90).
(9) FIG. 4 is an exemplary functional or illustrative schematic view of Audio Device 100 with Active Noise Control System (ANC) (340) including Active and/or Adaptive Noise Control with Audio Source Input (352), ANC Output (362), At Least One Microphone Input (312, 322), At Least One Microphone (310, 320), and a Planar Magnetic Transducer (90).
(10) FIG. 5 is an exemplary functional or illustrative schematic of reducing time delay from the diaphragm to the microphone by embedding the microphone on the diaphragm of the transducer itself. FIG. 5 shows a Hybrid Feed-Forward-Feedback Audio Device 100 with Active Noise Control System (ANC) (340) including Active and/or Adaptive Noise Control with Audio Source Input (352), ANC Output (362), At least one Microphone (310, 320), at least One Microphone Input (312, 322), Audio Source Input (352), ANC Output (362), and a Non-Voice-Coil Transducer (90).
(11) FIG. 5 Includes a diaphragm (94) including an electro-mechanical system (325) for converting the input (365) into the output (367) for providing sound waves (390), and a mechano-electrical system (326) coupled to the diaphragm (94) having a mechano-electrical output (327) such that motion of sound waves (390) impacting the diaphragm (94) generates a proportionate mechano-electrical output signal (328), wherein the mechano-electrical system (326) acts as the at least one microphone (310, 320) connected to the at least one microphone input (312, 322).
(12) FIG. 6 is an exemplary functional or illustrative schematic view of diaphragm trace pattern with 2 separate circuits. Dual loop main circuit carries the current from the amplifier which interacts with magnetic field and moves diaphragm back and forth creating sound. Movement of the diaphragm causes a small voltage to be induced in a second circuit which can be used as a feedback signal for ANC.
(13) FIG. 7 is an exemplary functional or illustrative schematic view of Feed-Forward Audio Device 100 with Active Noise Control System (ANC) (340) including Active and/or Adaptive Noise Control with Audio Source Input (352), ANC Output (362), Feed Forward Microphone (310), Audio Source Input (352), ANC Output (362), and a Non-Voice-Coil Transducer (90).
(14) FIG. 8 is an exemplary functional or illustrative schematic view of Feedback Audio Device 100 with Active Noise Control System (ANC) (340) including Active and/or Adaptive Noise Control with Audio Source Input (352), ANC Output (362), Feedback Microphone (320), Feedback Microphone Input (322), and a Non-Voice-Coil Transducer (90).
(15) FIG. 9 is an exemplary functional or illustrative schematic view of Audio Device (100) with Active Noise Control System (ANC) (340) including Active and/or Adaptive Noise Control with of Hybrid Feedforward-Feedback Audio Device 100 with Active Noise Control System (ANC) (340) including Active and/or Adaptive Noise Control with Audio Source Input (352), ANC Output (362), Microphone inputs (312, 322), Microphones (310, 320), and a Non-Voice-Coil Transducer (90).
(16) FIG. 10 is an exemplary functional or illustrative schematic view of Audio Device 100 with Active Noise Control System (ANC) (340) including Active and/or Adaptive Noise Control with Audio Source Input (352), ANC Output (362), At Least One Microphone input (312, 322), At Least One Microphone (310, 320), and a Non-Voice-Coil Transducer (90).
(17) FIG. 11 is an exemplary functional or illustrative schematic view of Audio Device (100) with Active Noise Control System (ANC) (340) including Active and/or Adaptive Noise Control withof Audio Device 100 with Active Noise Control System (ANC) (340) including Analog and/or Digital Control System with Audio Source Input (352), ANC Output (362), At Least One Microphone input (312, 322), At Least One Microphone (310, 320), and a Non-Voice-Coil Transducer (90).
(18) FIG. 12 is a Cross-sectional View of Closed-Back Audio Device 100 with Housing (101), Planar Transducer (90), and Active Noise Control System (340).
(19) FIG. 13 is a Cross-sectional View of Closed-Back Audio Device 100 with Housing (101), Planar Transducer (90), and Active Noise Control System (340).
(20) FIG. 14 is a Cross-sectional View of Closed-Back Audio Device 100 with Housing (101), Planar Transducer (90), and Active Noise Control System (340).
(21) FIG. 15 is a Cross-sectional View of Open-Back Audio Device 100 with Housing (101), Planar Transducer (90), and Active Noise Control System (340).
(22) FIG. 16 is a Cross-sectional View of Open-Back Audio Device 100 with acoustically absorbent material (33) in Housing (101), Planar Transducer (90), and Active Noise Control System (340).
(23) FIG. 17 is a Cross-sectional View of Open-Back Audio Device 100 with Housing (101), Planar Transducer (90), and Active Noise Control System (340).
(24) FIG. 18 is a Cross-sectional View of Closed-Back Audio Device 100 with Housing (101), Electro-Static Transducer (394), and Active Noise Control System (340).
(25) FIG. 19 is a Cross-sectional View of Open-Back Audio Device 100 with Housing (101), Piezo-Electric Transducer (396), and Active Noise Control System (340).
(26) FIG. 20 is a Cross-sectional View of Closed-Back In-Ear Planar Earphone Audio Device 100 with Housing (101), Planar Transducer (90), and Active Noise Control System (340).
(27) FIG. 20 shows a cross-sectional illustrative view of one aspect of the present invention showing an in-ear planar magnetic earphone (100) with an open-back configuration and active noise cancellation. FIG. 20 shows a housing 101 which may be a singular housing 101, or it may comprise multiple components to construct the housing 101. As an example, FIG. 1 shows housing 101 comprising a bottom housing 15 and a top housing 110. In other embodiments, the housing 101 may not be shaped similarly to the housing 101 as shown in FIG. 1. FIG. 1 shows the bottom housing 15, part of which becomes the sound port 10 approximately at the point where the bottom housing 15 fits into the ear canal (as shown in FIG. 28). The sound port 10 may be encompassed by an eartip 160 when placed into the ear canal. The eartip 160 is made of a soft flexible material such as foam, expanding foam, rubber, silicone, or similar material. This helps make the device comfortable in the ear and helps to create a seal around the eartip 160 such that no undesired air gap exists from the ear canal to the outside air caused by an inadequate fit between the eartip 160 and the ear canal. Eartips may be of various sizes to fit relatively snuggly into the ears of different people with different diameter ear canals.
(28) Alternatively, instead of an eartip 160, the sound port 10 can be designed to exclusively fit a specific person's ears (not shown). Creating a mold of a specific person's ear canal to design a custom-fitted earphone, sound port, or eartip is well known in the earphone industry. A sound port 10 may be designed exclusively to be fitted to a specific person's ear so that the sound port may be even longer than shown in FIG. 20 and optionally fit deeper into that fitted person's ear such that a good seal is formed between the air in the ear canal and the outside air.
(29) With this approach, the sound port 10 may be made to be removable from the bottom housing 15 such that different people can remove and attach the same earphone 15 with their own exclusively fitted sound port 10.
(30) In FIG. 20, coupled to the bottom housing 15 is an acoustically transparent top housing 110. This acoustically transparent top housing 110 includes acoustically transparent openings 6. The acoustically transparent top housing 110 is the reason the earphone 15 is called open or open-backed. In this case, the ANC causes effective external noise reduction while still preserving the sensation of an open space, thus avoiding the unnatural occlusion effect of closed-back earphones or headphones.
(31) If the space between the diaphragm and top housing is filled with acoustically absorptive material the design is considered to be semi-open or semi-open-backed (not shown). This semi-open-backed design may be used with all of the planar types of transducers, as later described in FIG. 3, FIG. 5, and other open-backed headphones and earphones. Both the semi-open and semi-open-backed approaches equalize the back-pressure with the outside air and also preserve the sensation of an open space, avoiding the unnatural occlusion effect of closed-back earphones or headphones.
(32) Positioned on the bottom housing 15 or on the top housing 110 is diaphragm frame 96. In this planar magnetic earphone (100), the diaphragm frame 96 is a planar magnetic diaphragm frame 96. Suspended in the diaphragm frame 96 is a planar diaphragm 94. The planar diaphragm 94 is a light thin film held to a desired tautness by the diaphragm frame 96.
(33) A magnetic structure 92 is disposed on one or both sides of the diaphragm 94, wherein the magnetic structure 92 is held in place by a magnetic frame or mount (not shown). Here the magnetic structure 92 is only shown on one side of the diaphragm to reduce drawing clutter on the page. In actual practice, magnetic structures 92 may be placed on both sides of the diaphragm 94.
(34) Note that in FIG. 20 of the active noise-controlled earphone, the magnetic structure 92 and diaphragm 94 are illustratively shown as a planar magnet array for a planar magnet array transducer. In practice, other planar transducers and diaphragms may be used, such as electrostatic transducers, piezoelectric transducers, AMT (air Motion Transformer), thin rigid diaphragm planar transducer or other planar transducers. In addition, other types of transducers may be used, such as dynamic transducers.
(35) Planar diaphragm 94 has electrical conductors (not shown) disposed on one or both sides of the planar diaphragm 94. These conductors form at least one electrical circuit (not shown). When an electrical signal for sound is transmitted through the electrical conductors, the diaphragm 94 is attracted to or repelled by the magnets in the magnetic structure 92 to create an acoustic signal. The arrangement of the magnets (not shown) in magnetic structure 92 and the arrangement of the conductors (not shown) on diaphragm 94 are variously selected to optimize the magnetic and electrical interaction required to achieve the earphone 15 designer's goals.
(36) External noise sensing microphone 11 is disposed on acoustically transparent top housing 110 such that external noise or sounds from the environment will be sensed by external noise sensing microphone 11 and converted into electrical signals corresponding to the noise. These signals are carried on conductors (not shown) to an active noise cancellation processor (not shown). In processing, the anti-noise signal (equal amplitude, inverse of the noise signal) may be delayed in time and then is added to or subtracted from the original sound signal. It is then transmitted to the diaphragm 94, where the noise and anti-noise cancel each other, such that only the original source signal is emitted from the diaphragm 94 and into the bottom housing 15 and sound port 10. This operation where external noise sensing microphone 11 is in front of the diaphragm 94 is termed forward active noise cancellation or feed-forward ANC.
(37) It is important to note that FIG. 20 is an illustrative drawing with the external noise sensing microphone 11 illustratively placed immediately inside the acoustically transparent housing 110 at the center. In fact, the external noise sensing microphone 11 is not limited to where it may be placed. It may be placed anywhere inside, outside, or mounted flush with the surface of the external noise sensing microphone 11. Here the term external is used because the microphone 11 is capturing noise and sounds outside of or external to the earphone (100). Thus, an external noise sensing microphone 11 could be mounted anywhere inside the cavity formed between the top housing 110, the diaphragm 94 and diaphragm frame 96, which we will call the outside cavity. Likewise, the external noise sensing microphone 11 could be mounted anywhere outside the top housing 110, or flush with the top housing 110. Thus, the present invention is not limited strictly to the placement of the external noise sensing microphone 11. Instead, the placement of the external noise sensing microphone 11 may be varied to achieve certain acoustical results.
(38) Further, there may be more than one external noise sensing microphone 11. These multiple external noise sensing microphones 11 again may be place wherever they need to be to achieve certain acoustical results.
(39) Continuing with FIG. 20, inside the of the cavity formed between the bottom housing 15, the sound port 10, and the diaphragm 94 (called the inside cavity) is disposed a uniquely designed illustratively shown phase plug 70 [also described as a phase shifting element, phase-shift plug, phase plug, phase controlling element, or commercially named Fazor 70]. This phase plug 70 may be inserted into or molded on the bottom housing 15. The phase plug 70 may be formed in various shapes to affect the acoustical properties of the device. These acoustical properties may comprise phasing and phase-shifting, decreased sound diffraction, improved acoustic loading, improved reflection characteristics, and decreased sound distortion. By varying the shape and placement of the phase-shifting element 70 within the internal cavity (which we will call the inside cavity or inside chamber) in the bottom housing 15, we can change the acoustical properties of the device. The change in shape of at least one waveguide between the phase-shifting element 70 and the inside surface of the bottom housing 15 will enable finely controllable acoustic properties. The internal phase-shifting element 70 is not limited to a single instance, as there may be multiple internal phase-shifting elements 70 within the inside cavity [not shown]. The internal phase-shifting element 70 is also not limited to being in the center of the inside cavity. The phase-shifting element 70 may be held in place in various ways, such as being attached to the bottom housing 15 with one or more spokes, attached directly to the inside surface of the bottom housing 15, or any other ways known in the attachment art.
(40) This phase plug 70 serves several other purposes such as maintaining phase coherence, decreasing reflections, increasing compression, and increasing the pressure wave to the output of the sound port 10. The phase plug 70 is described more fully in other patents.
(41) FIG. 20 also shows an illustrative example of an ear tip 160. The ear tip 160 may comprise a soft material that is as sound proof as possible while fitting snuggly in the ear canal and creating a good sound seal.
(42) In the inside cavity, FIG. 20 shows the phase plug 70 with an error detection microphone 12 inserted into the phase plug 70. As shown in FIG. 20, for illustrative purposes, the error detection microphone 12 is placed in a hollowed-out hole in the phase plug 70. On the other side of the internal microphone 12 is an internal microphone opening 13 nearer the ear. This allows the sound waves to flow through the tunnel, instead of causing interference should the sound waves reflect back toward the diaphragm 94.
(43) The error detection internal microphone 12 is used to receive both the original electrical sound signal transmitted to the diaphragm plus any external noise that has penetrated the inside chamber. This summed signal is sent to a processor to generate the required signal to do ANC.
(44) In at least one embodiment of the present invention, the tunnel through the phase plug 70, in which the internal microphone 12 is placed and where the internal microphone opening 13 exists, is a straight path tunnel as is shown illustratively in FIG. 20. In at least one embodiment of the present invention, the tunnel through the phase plug 70, in which the internal microphone 12 is placed, and the internal microphone opening 13 exists, is not a straight path tunnel as is shown illustratively in FIG. 20. In at least one embodiment of the present invention, the tunnel through the phase plug 70, may wind around inside the phase plug 70 such that the length (and hence time delay) of the tunnel matches the length (and time delay) of the waveguides formed between the phase plug 70 and the bottom housing 15. This enables phase coherence not only around the phase plug 70, but also through the phase plug 70 tunnel.
(45) As stated previously, FIG. 20 is illustrative. Thus, error detection (internal microphone) 12 may be located anywhere in the inside cavity. Error detection (internal microphone) 12 may be mounted on an external surface of the phase plug 70, or on an internal surface of the bottom housing 15. Error detection (internal microphone) 12 may be attached on the outside of these surfaces, mounted flush on the surface, or burrowed into a hole in the surface. An illustrative example of being burrowed into a surface (in this case, in phase plug 70) is shown in FIG. 20 where error detection (internal microphone) 12 is burrowed into a hole in phase plug 70.
(46) Further, the present invention is not limited to a single microphone in either cavity. Multiple microphones can be used in any location for varying acoustical effects and noise cancellation.
(47) Since FIG. 20 is an illustrative example of the present invention, it should be understood there are many variations of the present invention (not shown) that are encompassed within the present invention.
(48) For larger circumaural designs (over-the-ear, with the headphones completely enclosing the ears), or supra-aural designs (on-the-ear headphones), the larger size of the planar drivers (or other drivers) may comprise multiple feedback and feed-forward microphones. These may be combined with processors or multi-processors, including digital signal processors (DSPs) such that multiple inputs may be treated by the processor or processors in an algorithmic manner to achieve highly accurate estimates of error signals, thus improving noise cancellation. A simple example of this might be summing the inputs in a weighted fashion, but any other simple to highly sophisticated algorithm may be used to achieve maximal, optimal, or desired noise cancellation.
(49) In addition, for circumaural or supra-aural planar headphones incorporating planar transducers, (including but not limited to planar magnetic transducers, electrostatic transducers, and piezo-electric transducers), the phase-plug with waveguides designs help linearize the response, thus making them better suited for ANC.
(50) Since ANC headphones and earphones are generally for mobile use, low power and efficiency is important. Thus, improvements in planar magnet efficiency in previously referenced U.S. Pat. No. 9,287,029, Magnet Arrays will make them better suited for ANC.
(51) FIG. 22 is a Cross-sectional View of Open-Back In-Ear Planar Magnetic Earphone Audio Device 100 with Housing (101), Planar Transducer (90), and Active Noise Control System (340).
(52) FIG. 23 is a Cross-sectional View of Open-Back In-Ear Planar Earphone Audio Device 100 with Housing (101), Planar Transducer (90), and Active Noise Control System (340).
(53) FIG. 24 is a Cross-sectional View of Open-Back In-Ear Planar Earphone Audio Device 100 with Housing (101), Planar Transducer (90), and Active Noise Control System (340).
(54) FIG. 25 is a Cross-sectional View of Open-Back In-Ear Planar Magnetic Earphone Audio Device 100 with Housing (101), Planar Transducer (90), and Active Noise Control System (340).
(55) FIG. 26 is a Cross-sectional View of Open-Back In-Ear Planar Magnetic Earphone Audio Device 100 with Housing (101), Planar Transducer (90), and Active Noise Control System (340).
(56) FIG. 27 is a Cross-sectional View of Open-Back In-Ear Planar Magnetic Earphone Audio Device 100 with Housing (101), Planar Transducer (90), and Active Noise Control System (340).
(57) FIG. 28 is a Cross-sectional View of Closed-Back In-Ear Planar Earphone Audio Device 100 with Housing (101), Planar Transducer (90), and Active Noise Control System (340).
(58) FIG. 29 is a comparison chart between an electrical input signal to two different transducers at the top, and two charts at the bottom showing the SPL sound wave responses for two different types of transducers. The planar transducer at the bottom matches the great detail in the sound wave that almost exactly matches the input signal. The other signal at the bottom is the sound wave response for a voice-coil style transducer with a cone and dome. Notice the distortion with smearing of the high frequencies as one example of voice-coil-style distortion.
(59) FIG. 30 shows a planar magnetic earphone properly inserted into an ear canal. A proper seal improves low frequency performance.
(60) Turning now to FIG. 21, we see the similar in-ear planar magnetic ear phone with both feedback and feed-forward microphones for ANC. However, in FIG. 2, there is now an acoustically non-transparent housing 110a, due to a closed back. This closed back is intended to decrease the noise at certain frequencies. Because of the closed back and the varied amount of noise cancellation, the processor may need to be tuned or adjusted to compensate.
(61) FIG. 22 illustrates an embodiment of the present invention with feedforward and feedback microphones for ANC. In this embodiment, the planar magnetic transducer has been replaced by an electrostatic transducer 94a and 96a, and the top housing has reverted to the acoustically transparent top housing 110. This provides the open-backed feel as described in FIG. 20. The semi-open-back may be accomplished by inserting acoustically absorptive material in the outside cavity.
(62) FIG. 23 illustrates an embodiment of the present invention with feedforward and feedback microphones for ANC. In this embodiment, the planar magnetic transducer has been replaced by an electrostatic transducer 94a and 96a, and the top housing has reverted to the acoustically non-transparent top housing 110a.
(63) FIG. 24 illustrates an embodiment of the present invention with feedforward and feedback microphones for ANC. In this embodiment, the planar magnetic transducer has been replaced by a piezoelectric transducer 94a and 96a, and the top housing has reverted to the acoustically transparent top housing 110. This provides the open-backed feel as described in FIG. 20. The semi-open-back may be accomplished by inserting acoustically absorptive material in the outside cavity.
(64) FIG. 25 illustrates an embodiment of the present invention with feedforward and feedback microphones for ANC. In this embodiment, the planar magnetic transducer has been replaced by a piezoelectric transducer 94a and 96a, and the top housing has reverted to the acoustically non-transparent top housing 110a.
(65) FIG. 26 shows an embodiment of the present invention with feedforward and feedback microphones for ANC using the original planar magnet transducer configuration with control leak openings. When the ear tip makes a good seal, then the planar magnet array configuration works very well, and yields extremely low frequencies. However, when ANC is used, especially feedback ANC, and a leak in the seal between the ear canal and the ear tip 160 occurs, it may cause the system to be unstable. To avoid this sudden destabilization, controlled leaks may be put into the bottom housing. This causes a slight loss of very low frequencies, but it stabilizes the system.
(66) Returning to FIG. 26, control leak openings have been introduced to stabilize the system with ANC. In one embodiment of the present invention, control leaks may be made in the bottom housing 115 from the outside air to inside the sound port. This also relieves some pressure into the ear.
(67) In FIG. 27, control leak openings have been introduced. These control leaks are far up the bottom housing 115 to just below the diaphragm 94. The final position of the holes is chosen to achieve the best sound performance and the most effective noise canceling. This may variy for different types of earphones.
(68) FIG. 28 demonstrates the application of ANC in a planar magnetic headphone with an open back. In this case, the ANC causes effective external noise reduction while still preserving the sensation of an open space, thus avoiding the unnatural occlusion effect of closed-back earphones or headphones.
(69) For larger circumaural or supra-aural designs, the larger size of the planar drivers may comprise multiple feedback and feed-forward microphones. These may be combined with processors or multi-processors whose inputs may be summed in a weighted fashion to achieve highly accurate estimates of error signals, thus improving noise cancellation.
(70) FIG. 28 demonstrates the application of ANC in a planar magnetic headphone, but with a closed back. The result of this is excellent noise cancellation with the benefit of high quality music reproduction provided by planar magnetic technology.
(71) FIG. 28 demonstrates the application of ANC in an electrostatic headphone with an open back. In this case, the ANC causes effective external noise reduction while still preserving the sensation of an open space, thus avoiding the unnatural occlusion effect of closed-back electrostatic earphones or headphones.
(72) FIG. 28 demonstrates the application of ANC in an electrostatic headphone, but with a closed back. The result of this is excellent noise cancellation with the benefit of high quality music reproduction provided by electrostatic technology.
(73) FIG. 28 demonstrates the application of ANC in a piezoelectric headphone with an open back. In this case, the ANC causes effective external noise reduction while still preserving the sensation of an open space, thus avoiding the unnatural occlusion effect of closed-back piezoelectric earphones or headphones.
(74) FIG. 28 demonstrates the application of ANC in a piezoelectric headphone, but with a closed back. The result of this is excellent noise cancellation with the benefit of high quality music reproduction provided by piezoelectric technology.
(75) FIG. 28 shows the similar configuration, but without the planar transducers. Here a dynamic driver with an open back is introduced instead of the previous planar drivers. In this case, the ANC causes effective external noise reduction while still preserving the sensation of an open space, thus avoiding the unnatural occlusion effect of closed-back dynamic driver earphones or headphones.
(76) FIG. 30 is a cross-section illustrative example of the present invention being inserted properly in an ear with ANC. A proper seal is very important for good low frequency performance.
(77) The present invention may further comprise method patents comprising the steps of actively and passively cancelling noise in planar transducer headphone and earphone technologies.
(78) The present invention may also comprise system patents comprising systems of actively and passively cancelling noise in planar transducer headphone and earphone technologies.
(79) The foregoing descriptions of embodiments of the present invention have been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Various additional modifications of the described embodiments of the invention specifically illustrated and described herein will be apparent to those skilled in in the art, particularly in light of the teachings of this invention. It is intended that the invention cover all modifications and embodiments, which fall within the spirit and scope of the invention. Thus, while embodiments of the present invention have been disclosed, it will be understood that these are not limited to the description herein but may be otherwise modified based upon this invention.
(80) Present embodiments satisfy the above described needs and provide further related advantages.
(81) The foregoing descriptions of embodiments of the present invention have been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Various additional modifications of the described embodiments specifically illustrated and described herein will be apparent to those skilled in in the art, particularly in light of the teachings of this invention. It is intended that the invention cover all modifications and embodiments, which fall within the spirit and scope. Thus, while embodiments of the present invention have been disclosed, it will be understood that these are not limited to the description herein but may be otherwise modified based upon this invention.
