JP2014519791A - Audio device with electroactive polymer actuator - Google Patents

Abstract

【Task】
A sensory enhanced audio device comprising an electroactive polymer module is disclosed. The electroactive polymer module may be disposed, for example, in a headphone ear cup. The module comprises an electroactive polymer actuator array having at least one elastomeric dielectric element disposed between the first and second electrodes. The tray may be configured to receive an electroactive polymer actuator array and a mass coupled to the actuator array. A circuit is electrically connected to the electroactive polymer actuator array. The circuit is a circuit for generating a drive signal and operating the electroactive polymer actuator array according to the drive signal. The drive signal is preferably in a frequency range from about 2 Hz to about 200 Hz.
[Selection] Figure 1

Description

Cross-reference to related application This application is a US Provisional Patent Application No. 61 / 497,556 filed on June 16, 2011 under US Patent Act 119 (e), “ELECTRO-MECHANICAL SYSTEM FOR SIMULATING LOW FREQUENCY AUDIO SENSATIONS ”and 61 / 564,437 filed on November 29, 2011“ ACOUSTIC NOISE REDUCTION TECHNIQUES FOR TACTILE HEADPHONE ACTUATORS ”, the entire disclosure of each of these provisional applications is hereby incorporated by reference. Incorporated into.

  In various embodiments, the present disclosure generally relates to an electromechanical system for simulating a low frequency acoustic sensation. More specifically, the present disclosure relates to an audio device that includes an electroactive polymer actuator or transducer. In particular, the present disclosure relates to headphones comprising an electroactive polymer actuator and mechanical and electrical acoustic noise reduction modules.

  Conventional acoustic headphones include a pair of earcups connected by a headband. The ear cup includes a loudspeaker that is mounted within the ear cup housing portion and held near the user's ear. The headphones include an electric wire for connecting a loudspeaker to an audio signal source such as an audio amplifier, a radio, a CD player, a portable media player, a computer, a tablet, a portable device, or a game machine. Some types of conventional headphones also include electronic circuitry for signal conditioning and processing of the acoustic signal received from the audio signal source. A type of audio headphone that is not equipped with a headband and is specifically designed to be put directly into the user's ear is also known as an earbud or spoken earbud.

  Conventional audio signals include acoustic frequency components in the range of about 20 Hz to about 20 kHz. Most sound reproduction systems (home audio, headphones, earbuds, telephones, speakers) cannot effectively cover the entire audible frequency range and typically have poor low frequency (less than about 200 Hz) performance. Therefore, large acoustic radiators are used to accurately reproduce low frequency audio signals. Typically, these devices are physically large and consume a significant amount of power. An example of an acoustic radiator is a subwoofer cabinet used in a home theater system. It is difficult to mount low-frequency audio content on a relatively small sound reproduction device (such as headphones). Some of the methods for this basically require that air be sealed around the user's ears and use directly coupled pneumatic waves. This method is effective, but it also applies uncomfortable pressure even at moderate sound levels. Higher sound levels can be dangerous and can cause short or long term hearing loss.

  Bone conduction is the conduction of sound through the skull bones to the inner ear (http://en.wikipedia.org/wiki/Bone_conduction). What you hear differently when you record and play your own voice is due to bone conduction. Because the skull conducts low frequencies better than the air, its own voice sounds lower and deeper than others hear. Bone conduction also explains why the recording of your own voice sounds higher than your familiar voice. Bone conduction is said to have been discovered by composer Ludwig van Beethoven, who was almost deaf. Beethoven is said to have found a way to listen to music through the jawbone by biting a stick on a piano.

  Some hearing aids employ bone conduction and achieve the same effect as listening directly by ear. The headset is ergonomically placed on the temple and cheek and an electromechanical transducer that converts electrical signals into mechanical vibrations sends sound through the skull to the inner ear. Similarly, a microphone can be used to record speech with bone conduction. The first description of a bone conduction hearing aid was provided in US Pat. No. 1,521,287.

  Bone conduction devices can be classified into three types: hands-free headsets or headphones; hearing aids and hearing aids; and specialized communication devices (eg, for underwater and high noise environments). Bone conduction devices have several advantages over conventional headphones: Such devices are “ear-free”, improving usability and safety; producing clear sound in very noisy environments Can be used in conjunction with hearing protection; can provide stereo sound perception.

  Disadvantages of the device: Some implementations require more power than headphones; some devices cannot provide as clear recording and playback as conventional headphones and microphones due to the reduced frequency bandwidth.

  An example of a bone conduction speaker is a piezoelectric bending disk having a diameter of about 40 mm and a thickness of 6 mm, overmolded with rubber used by a scuba diver. The connecting cable is molded into a disk, resulting in a sturdy and water resistant assembly. In use, the speaker is strapped to one of the domed bone protrusions behind the ear. As expected, the sound produced appears to be heard from within the user's head, but can be surprisingly clear and crisp.

  The bone conduction audio device is not limited to a headset or headphones, and can be used in other parts of the body as long as the device can be coupled to the skeletal system.

  The present disclosure provides an improved audio device (such as headphones) with an electromechanical system (such as an electroactive polymer actuator) for stimulating low frequency acoustic sensations. The improved audio device comprises a mechanical and electrical acoustic noise reduction module.

  Another application that can be addressed by the present invention is in sensory enhanced audio devices where information other than audio signals is communicated to the user. An early example of sensory enhancement headphones that carry encoded signals is described in US Pat. No. 1,531,543.

  In one embodiment, the present disclosure applies to a sensory enhanced audio device. The audio device includes an electroactive polymer actuator array having at least one elastomeric dielectric element disposed between the first and second electrodes. The tray may be configured to receive an electroactive polymer actuator array and a mass coupled to the electroactive polymer actuator array. A circuit is electrically connected to the electroactive polymer actuator array. The circuit is preferably a circuit for generating a drive signal in a frequency range from about 2 Hz to about 200 Hz to move or vibrate the electroactive polymer actuator array in accordance with the drive signal. Electroactive polymer actuators cause the ear cup to oscillate (vibrate) when it is a headphone, and the vibration tracks the incoming low frequency sound, thereby generating high pressure sound waves that can be dangerous to the eardrum. Without giving the feeling of low frequency voice. The electroactive polymer actuators disclosed herein enhance the “listening” experience of conventional audio devices (such as headphones). With appropriate drive signals, the actuator may be used to convey information not related to the audio signal. These and other advantages and benefits of the present invention will become apparent in the Detailed Description below.

  The present invention will now be described with reference to the drawings for purposes of illustration and not limitation.

1 is a perspective view showing a sensory enhancement headphone according to one embodiment of the present invention. FIG. FIG. 2 is a perspective view showing the left ear cup of FIG. 1 according to one embodiment. FIG. 2 is a front view of the left ear cup of FIG. 1 according to one embodiment. FIG. 2 is a perspective view showing the right ear cup of FIG. 1 according to one embodiment. FIG. 3 is a rear view of the right ear cup of FIG. 1 according to one embodiment. FIG. 6 shows a cross-section of the right ear cup along section line 6-6 of FIG. 4 according to one embodiment. FIG. 6 shows a cross-section of the right ear cup along section line 6-6 of FIG. 4 according to one embodiment. FIG. 8 is a front view of the ear cup of FIGS. 6 and 7 according to one embodiment. 1 is a cutaway view illustrating an electroactive polymer system, according to one embodiment. FIG. 1 is a schematic diagram illustrating one embodiment of an electroactive polymer system to illustrate the operating principle. FIG. FIG. 3 illustrates a configuration of a 1 bar electroactive polymer actuator array, according to one embodiment. FIG. 3 illustrates a configuration of a 3-bar electroactive polymer actuator array, according to one embodiment. FIG. 3 illustrates a configuration of a 6 bar electroactive polymer actuator array, according to one embodiment. 1 is an exploded view illustrating one embodiment of an electroactive polymer actuator system for an acoustic headphone system, according to one embodiment. FIG. FIG. 3 illustrates an electroactive polymer actuator and speaker element, according to one embodiment. FIG. 14 illustrates the electroactive polymer actuator of FIG. 13 with the mass of FIG. 13 removed to expose the electroactive polymer actuator array, according to one embodiment. FIG. 15 illustrates the electroactive polymer actuator of FIG. 14 with the tray removed, according to one embodiment. FIG. 15 illustrates the electroactive polymer actuator of FIG. 14 with the mass and cartridge portion of the electroactive polymer actuator array removed to show only the tray and lower rigid frame element, according to one embodiment. 1 is a top view of an electroactive polymer actuator, according to one embodiment. FIG. FIG. 18 illustrates a cross section of the electroactive polymer actuator of FIG. 17 at section line 18-18, according to one embodiment. 1 is a perspective view illustrating an electroactive polymer actuator, according to one embodiment. FIG. FIG. 20 is a rear view of the electroactive polymer actuator of FIG. 19 according to one embodiment. FIG. 20 illustrates a cross section of the electroactive polymer actuator of FIG. 19 at section line 21-21, according to one embodiment. FIG. 20 is a perspective view of the electroactive polymer actuator of FIG. 19 with the top plate removed to show the mass located in the suspension tray of the flex suspension system, according to one embodiment. FIG. 23 is a perspective view of the electroactive polymer actuator of FIG. 22 with the mass removed to show an adhesive layer disposed over the electroactive polymer actuator array, according to one embodiment. FIG. 24 is a perspective view of the electroactive polymer actuator of FIG. 23 with the flex tray removed to better show the base plate and the 3-bar electroactive polymer actuator array according to one embodiment. FIG. 25 is a perspective view of the electroactive polymer actuator of FIG. 24 with the electroactive polymer actuator array removed to show the base plate and adhesive layer, according to one embodiment. FIG. 26 is a perspective view of the electroactive polymer actuator of FIG. 25 with the adhesive layer and flex circuit removed to show the base plate and opening, according to one embodiment. FIG. 20 illustrates a cross section of the electroactive polymer actuator of FIG. 19 at section line 27-27, according to one embodiment. The figure which shows one Embodiment of an electroactive polymer actuator. FIG. 29 is a perspective view of the electroactive polymer actuator of FIG. 28 with the mass removed to show the adhesive layer, according to one embodiment. FIG. 3 illustrates a base portion of a tray with an electroactive polymer actuator array removed, according to one embodiment. FIG. 4 is a perspective view illustrating a portion of an electroactive polymer actuator array of electroactive polymer actuator 800, according to one embodiment. A graph of test data showing the frequency response of an electroactive polymer actuator without a flex suspension system and a sprung mass with frequency (Hz) on the horizontal axis and stroke (mm) on the vertical axis. A graph of test data showing the frequency response of an electroactive polymer actuator with a flex suspension system and a sprung mass with frequency (Hz) on the horizontal axis and stroke (mm) on the vertical axis. The perspective sectional view showing one embodiment of an ear cup. FIG. 35 is a perspective cross-sectional view showing the ear cup of FIG. FIG. 35 is a front sectional view showing the ear cup of FIG. 34. FIG. 37 shows one embodiment of the ear cup of FIGS. 34-36 with the ear covering cushion and housing removed to expose the lower stand-alone tray attached to the acoustic cavity on the back side of the speaker. FIG. 38 shows the ear cup of FIG. 37 with the stand-alone module housing removed to expose the electroactive polymer actuator array, according to one embodiment. FIG. 39 illustrates the ear cup of FIG. 38 with the electroactive polymer actuator array removed to expose the mass according to one embodiment. FIG. 40 shows the ear cup of FIG. 39 with the mass removed, according to one embodiment. FIG. 3 is a bottom view of an acoustic cavity showing a speaker mounted therein according to one embodiment. FIG. 3 shows an embodiment of an electroactive polymer headphone comprising an electroactive polymer actuator housed in a first housing portion of an earcup. 1 is a block diagram illustrating an electronic circuit for generating a low frequency audio signal for driving an electroactive polymer actuator and reducing undesirable acoustic noise, according to one embodiment. FIG. FIG. 44 is a graph illustrating harmonic distortion measurements without using the inverse polynomial circuit (eg, “inverse square root circuit”) shown in FIG. 43, according to one embodiment. FIG. 44 is a graph showing measured values of harmonic distortion when the inverse polynomial circuit (“square root circuit”) shown in FIG. 43 is used according to one embodiment. FIG. 44 illustrates one embodiment of the inverse polynomial circuit (eg, “inverse square root circuit”) shown in FIG. 43, according to one embodiment. FIG. 13 is a partially cutaway view of the electroactive polymer module of FIG. 12 with a flex suspension system, according to one embodiment. FIG. 48 is a schematic diagram illustrating one embodiment of the electroactive polymer module of FIG. 12 with the flex suspension system of FIGS. 12 and 47 with a flex tray, according to one embodiment. FIG. 49 illustrates oscillating motion in the X and Y axes to model the motion in the X and Y directions of the flex suspension system illustrated in FIGS. 12 and 47-48, according to one embodiment. FIG. 49 illustrates oscillating motion in the X and Z axes to model the motion in the X and Z directions of the flex suspension system illustrated in FIGS. 12 and 47-48, according to one embodiment. FIG. 49 is a schematic diagram illustrating a bent tray movement stop of the bent suspension system shown in FIGS. 12 and 47-48 according to one embodiment. FIG. 3 is a schematic diagram illustrating a beam model of a flexural connection according to one embodiment. FIG. 3 shows an embodiment of a flex tray with the mass removed, according to one embodiment. The figure which shows the part of one Embodiment of a bending | flexion tray.

Before describing embodiments of the sensory enhancement audio device and audio noise reduction module of the present invention in detail, the application or use of the disclosed embodiments will be described in detail in the structure and configuration of the portions described in the accompanying drawings and description. Note that it is not limited to: The disclosed embodiments may be implemented or incorporated in other embodiments, variations, and variations, and may be implemented or performed in various ways. Further, unless otherwise specified, the terms and expressions used herein are selected for the purpose of describing the embodiments for purposes of illustration and convenience, and any of the embodiments are disclosed. It is not intended to be limited to any particular embodiment. Furthermore, any one or more of the disclosed embodiments, embodiment expressions, and examples may be used without limitation to other disclosed embodiments, embodiment expressions, and examples. It can be combined with any one or more. Thus, combinations of elements disclosed in one embodiment and elements disclosed in another embodiment are considered to be within the scope of this disclosure and the appended claims.

  The present invention provides a sensory enhanced audio device comprising an actuator system having a mechanical quality factor of less than about 10 and a circuit electrically connected to the actuator system, the circuit generating a drive signal The circuit for operating the actuator system according to the drive signal.

  The present invention further includes at least one ear cup and an electroactive polymer actuator array disposed within the at least one ear cup, wherein the electroactive polymer actuator is disposed between the first and second electrodes. And a sensory enhancement headphone comprising: an electroactive polymer actuator array comprising at least one elastomeric dielectric element; and a circuit electrically connected to the electroactive polymer actuator array, wherein the circuit generates a drive signal. And a circuit for vibrating the electroactive polymer actuator array in accordance with the drive signal.

  The drive signal used to move the actuator system of the sensory enhancement audio device is derived from the audio signal. An actuator system useful in the present invention comprises an electroactive polymer actuator array with at least one elastomeric dielectric element disposed between first and second electrodes.

  In one embodiment, the drive signal is designed to move the actuator system to convey other information rather than following the audio signal. Therefore, the control of the strength of the effect by the operation of the actuator system can be separated from the control of the strength of the audio signal. The user can, for example, increase the bass response of the headphones without experiencing an increase in acoustic response that may be uncomfortable or harmful to the user's hearing.

  In one embodiment, the present disclosure provides high quality low frequency vibration content to reinforce a limited acoustic sensation. This includes, for example, sensory enhanced audio devices such as sensory enhanced headphones with electroactive polymer actuators, as will be described in detail below. While not wishing to be bound by any particular theory, the inventor believes that the audio device of the present invention relies on a combination of bone conduction and sonic effects by including an electroactive polymer actuator.

  The present disclosure provides various embodiments of sensory enhancement headphones that include electroactive polymer actuators. The electroactive polymer actuator includes an electroactive polymer module based on a dielectric elastomer element. Such modules have a bandwidth and energy density suitable for implementing electroactive polymer actuators for use in acoustic headphones and for implementing mechanical acoustic noise reduction techniques. Such a module is made of a thin sheet with a dielectric elastomer thin film sandwiched between two electrode layers. When a sufficiently high voltage is applied to the electrodes, the two electrodes attract and compress the dielectric elastomer thin film. These modules are thin, low power, and may be coupled to an inertial mass to amplify the motion produced by the drive signal derived from the host device's audio signal source.

  In addition to providing various embodiments of electroactive polymer actuators for the implementation of sensory enhanced audio devices, in various aspects, the present disclosure provides a mechanical to reduce acoustic noise from various sources. And provide electronic technology. Each technique focuses on various operating conditions that produce undesired sound and are described separately below.

  Various embodiments of mechanical techniques for reducing acoustic noise are disclosed. In one embodiment, the mechanical noise reduction technique uses a flex suspension system that utilizes an electroactive polymer to substantially limit displacement to a single direction (e.g., a desired direction, such as a motion direction) Minimize and eliminate unwanted vibration modes. Test results support that stable vibrations substantially along the desired direction of motion can be achieved. Acoustic noise reduction is maximized when the desired direction is orthogonal to the axis of the acoustic radiator.

  In addition, embodiments of electronic techniques for reducing acoustic noise are disclosed. In one embodiment, the electronic acoustic noise technique uses a non-linear inverse transform to remove unwanted acoustic artifacts. The basic function of the electroactive polymer element depends on the electrostatic voltage generated by the electric field. In its simplest form, this pressure is proportional to the square of the electric field. Thus, a non-linear inverse transform such as a square root circuit can be used to correct for undesirable distortions in the actuator response. This applies to the isotropic, homogeneity, and linear dielectric properties of the electroactive polymer, as will be described in detail below. Other materials that are non-linear, anisotropic, or non-uniform may require additional electronic and / or mechanical correction, for example. A block diagram illustrating an example of an electronic topology for implementing a non-linear noise reduction technique is described below.

  Before describing various noise reduction techniques, this disclosure refers to FIG. 1, which is a perspective view of a sensory enhanced headphone 100 according to one embodiment. In the embodiment shown in FIG. 1, the headphone 100 includes a right ear cup 102 and a left ear cup 104 that are coupled to each other by a headband 106. Headband 106 may be any suitable conventional headband. The right and left ear cups 102 and 104 include corresponding right and left ear covering cushions 108 and 110, respectively. It should be understood that the ear coverings 108, 110 may have any shape, but traditionally such cushions are circular or oval to cover the ears. Since the ear covering cushions 108, 110 completely cover the ear, these headphones 100 can be designed to be completely sealed against the head, for example, to reduce any annoying external noise. The material of the cushions 108, 110 can be selected to adjust the degree of adhesion between the headphones and the user. Each of the right and left ear cups 102, 104 may preferably include an ear covering cushion 108, 110, a perforated speaker grill 112 (only right shown), and a housing 114 (only left shown). The housing 114 includes a speaker, an electroactive polymer actuator, and a circuit board that includes circuitry for driving the actuator, and in some embodiments, further includes mechanical and / or electronic acoustic noise reduction elements. Prepare. Embodiments of these elements are described below.

  FIG. 2 is a perspective view of the left ear cup 104, and FIG. 3 is a front view of the left ear cup 104. As shown in FIGS. 2 and 3, the left ear cup 104 includes an ear covering cushion 110 and a perforated speaker grill 116.

  FIG. 4 is a perspective view of the right ear cup 102, and FIG. 5 is a rear view of the right ear cup 102. As shown in FIGS. 4 and 5, the right ear cup 102 includes a housing 118.

  6 and 7 are cross-sectional views of the right ear cup 102 taken along section line 6-6 in FIG. FIG. 8 is a front view of the ear cup 102 shown in FIGS. 6 and 7. Since the left ear cup 104 is substantially similar to the right ear cup 102, for the sake of brevity and clarity of disclosure, the remainder of this disclosure will focus on the structure and function of the right ear cup 102, Such an attribute may equally relate to the left ear cup 102.

  Referring now in particular to FIGS. 6-8, in one embodiment, the right ear cup 102 includes a housing 118 that is suitable for mounting the speaker 120 and the electroactive polymer actuator 122 therein. Opening 124 is defined. In the embodiment illustrated in FIGS. 6-8, the actuator 122 may be referred to herein as an electroactive polymer module because it includes several sub-components. For example, in certain embodiments where the actuator 122 comprises three bars, the actuator 122 may be referred to as a three-bar electroactive polymer module without limitation. For example, in certain embodiments where the actuator 122 comprises a bent suspension system, the actuator 122 can be referred to as an inertial electroactive polymer module without limitation. Here, returning to FIGS. 6 to 8, the speaker 120 can be attached immediately behind the perforated speaker grill 112 as shown in the figure. However, in other embodiments, the position of the speaker 120 may be changed and attached to any suitable location within the opening 124 of the housing 118. In one embodiment, for example, the electroactive polymer actuator 122 may be attached to a portion of the inner wall 132 of the housing 118. In one embodiment, the actuator 122 may comprise a tray 126, an electroactive polymer actuator array 128, and a mass 130. In one embodiment, the tray 126 minimizes, reduces, or substantially eliminates acoustic noise that causes undesirable vibration modes, for example, by substantially limiting displacement to a single desired direction of motion. Therefore, it may be replaced with a bent suspension system as will be described in detail later. An electroactive polymer actuator array (such as actuator 128) may be referred to as an “n bar cartridge”, where “n” represents the number of actuator bars in the array. Thus, a three-bar stand-alone cartridge is an electroactive polymer actuator array comprising three actuator bars attached to a tray without a bending element. Conversely, a three bar inertial cartridge is an electroactive polymer actuator array with three bars attached to a flex suspension system. It should be understood that any disclosed headphone embodiment comprising a stand-alone actuator cartridge (such as tray 126) can be replaced with a bent suspension tray without limitation.

  Referring now to FIGS. 1-6, in one embodiment, a sensory enhancement headphone 100 comprising an electroactive polymer actuator 122 according to the present disclosure is in the audible frequency band (eg, about 20 Hz to about 20 kHz). It can create mechanical vibrations and provide a high quality acoustic sensation without generating high sound pressure in the ear. In one embodiment, each of the ear cups 102, 104 includes an electroactive polymer actuator 122. Each of the actuators 122 comprises a small mass 130 (preferably 1 to 50 g, more preferably 25 g) that is attached to the electroactive polymer actuator array 128 to form a simple mass / spring / damper resonant system. The low frequency part of the input sound is sent to the audio amplifier connected to the actuator 122. The electroactive polymer actuator 122 rocks (vibrates) the ear cups 102, 104, and the vibration does not generate high pressure sound waves that can be dangerous to the eardrum by tracking the input low frequency sound. Gives a sense of low frequency speech. The electroactive polymer actuator 122 disclosed herein enhances the “listening” experience of conventional audio headphones. Generation of low frequency (20 Hz to 200 Hz) vibrations expands the perceived frequency range of the audio headphones 100 to a lower frequency than the normal optimal range.

  However, the vibration generated by the electroactive polymer actuator 122 has a non-linear nature. In addition, the electroactive polymer actuator 122 may also generate acoustic vibrations, which may or may not be desirable. In the case of undesirable acoustic vibrations, the present disclosure further provides mechanical and electrical techniques to reduce undesirable acoustic effects to an acceptable level. Sometimes vibration can occur out of the plane of the speaker 120. If desired, increased vibration may be applied to the sensory enhanced headphones 100 by using a voice coil to drive the sprung mass. However, these implementations may introduce undesirable acoustic artifacts by providing a high Q system with low attenuation that vibrates long on the same axis as the acoustic radiator. However, in various embodiments, the electroactive polymer actuator 122 disclosed herein may be arranged such that the vibration plane is perpendicular to the axis of the acoustic radiator, thereby causing undesirable acoustic artifacts. Can be greatly reduced.

  The mechanical quality factor characterizes the mechanical damping of the system. The coefficient is the ratio of reactive energy to mechanical energy loss. As mentioned above, high Q systems vibrate longer, producing more acoustic artifacts and fewer distinct effects. A low Q value suggests that the system has a high mechanical loss, so that the vibration is easily damped and the movement of the actuator system becomes clear.

  For optimal performance, the Q value of the actuator system is preferably less than 10, more preferably less than 5, and most preferably between 1.5 and 3.

  As will be appreciated by those skilled in the art, QMS is a unitless quantity and characterizes the driver's mechanical damping or loss in suspension (surround suspension and spider suspension). The QMS varies between approximately 0.5 and 10 with a typical value of about 3. High QMS suggests lower mechanical loss and low QMS suggests higher loss. The main effect of QMS is on driver impedance, and high QMS drivers exhibit higher impedance peaks. The predictor of low QMS is the metal voice coil winding type. They need to be designed to have an electrical disconnect in the cylinder to act as an overcurrent brake to increase damping and reduce QMS. Some speaker manufacturers have placed shorted windings on the top and bottom of the voice coil to prevent gaps in the coil, but the sharp noise caused by this device when the driver is overdriven It was amazing and the owner felt the problem. Low QMS drivers are often made of non-conductive formers or manufactured from paper or various plastics.

  The resonant frequency of the actuator system is preferably tailored to the type of effect desired. For example, a resonance frequency in the range of 80 to 90 Hz is desirable to maximize the effect of percussion (such as a kick drum) or “punch”. The operation of the actuator system is preferably orthogonal to the direction of the sound wave when a separate speaker is used. Although other types of actuators can be used, such as piezoelectric transducers, voice coils, linear resonant motors, and eccentric motors, electroactive polymer actuators are particularly suitable for meeting the above criteria for this application. Yes. The electroactive polymer actuators have a low Q factor in the appropriate resonant frequency range of about 50-100 Hz, but in a small, lightweight and energy efficient form factor that is easily incorporated by sensory enhanced audio devices. Can be designed to hold fast response time and high output. The electroactive polymer actuator can be driven directly by the drive circuit so as to track and enhance the audio signal or to produce a particularly tuned effect independent of the audio signal. If the dielectric thin film of the electroactive polymer actuator has a low modulus of elasticity (preferably less than 100 MPa), the actuator operates using a smaller inertial mass than is required for high modulus materials (such as piezoelectric polymers or piezoelectric crystals). Can be amplified. This reduces the total volume and mass of the actuator system, which can be an important factor in the design of portable audio devices (such as headphones).

  For example, before beginning further description of various embodiments of the electroactive polymer actuator 122 shown in connection with FIGS. 6-8, it is provided with an electroactive polymer-based module suitable for use in audio devices such as headphones. In order to describe various integration devices, FIGS. 9 to 11 will be briefly described. FIG. 9 is a partial cutaway view showing an electroactive polymer system that can be integrated into the actuator 122 to provide vibration to the headphones 100. Accordingly, in one embodiment, the system comprises an electroactive polymer module 200. The electroactive polymer actuator 222 is configured to slide the output plate 202 (eg, sliding surface) relative to the fixed plate 204 (eg, fixed surface) when a voltage “V” is applied. Plates 202, 204 are separated by steel balls and have features that limit movement in a desired direction, limit operating distance, and withstand drop tests. For integration into a headphone device, the top plate 202 may be attached to an inertial mass such as the mass 130 shown in FIGS. In FIG. 9, the top plate 202 of the electroactive polymer module 200 is configured to be attached to the inertial mass or back side of the surface and includes a sliding surface that can move bi-directionally as indicated by arrow 206. Between output plate 202 and stationary plate 204, electroactive polymer module 200 is coupled to at least one electrode 208, optionally at least one partition 210, and a sliding surface (eg, top plate 202). And at least one output bar 212. A frame and partition 214 is coupled to a fixed surface (eg, lower plate 204). Module 200 may include any number of bars 212 configured in an array to amplify sliding surface motion. The electroactive polymer module 200 may be connected to the drive electronics of the actuator control circuit via a flexible cable 216. A potential difference “V” of preferably about 1 kV (preferably up to 5 kV, more preferably from 100 V to 5 kV, even more preferably from 300 V to 5 kV) is applied to the first and second conductive elements 218A, 218B of the flexible cable. May be.

  Dividing the electroactive polymer actuator 222 into (n) parts within a given footprint is a convenient way to set the passive stiffness and maximum generated force of the electroactive polymer system. The tensioned dielectric is held in place by a rigid material that defines an outer frame (such as a fixed plate 204) and one or more windows in the frame. Within each window is an output bar 212 of the same rigid frame material and an electrode 208 on one or both sides of the output bar 212. Alternatively, the rigid frame material may be replaced with an adhesive as disclosed below: International PCT Patent Application No. PCT / US2012 / 021511 “FRAMELESS ACTUATOR APPARATUS” filed on Jan. 17, 2112. , SYSTEM AND METHOD ". No. 61 / 433,640 “FRAMELESS DESIGN CONCEPT AND PROCESS FLOW” (filed Jan. 18, 2011), 61/442 No. 913 “FRAME-LESS DESIGN” (filed on Feb. 15, 2011), No. 61 / 447,827 “FRAMELESS ACTUATOR, LAMINATION AND CASING” (filed on Mar. 1, 2011), No. 61 / 477,712 Claims priority of "FRAMELESS APPLICATION" (filed April 21, 2011) and 61 / 545,292 "AN ALTERNATIVE TO Z-MODE ACTUATORS" (filed October 10, 2011). The entire disclosures of which are incorporated herein by reference. When a potential difference (V) is applied to the dielectric on one side of the output bar 212, a static voltage is generated in the elastomer, thereby expanding the area of the electrode and applying a force to the output bar 212. Since this force is proportional to the effective cross-sectional area of the electroactive polymer actuator 222, it increases linearly with the number of segments each increasing the effective width of the actuator. Each added segment effectively doubles the device by first shortening the segment in the extension direction (X) and secondly increasing the width (Y) resisting displacement, The passive spring constant is proportional to n2. The spring constant and the maximum generated force are linearly proportional to the number of dielectric layers (m).

Advantages of electroactive polymer module 200 include the ability to generate low frequency vibrations in the ear cup that can be felt substantially immediately by the user. Furthermore, the electroactive polymer module 200 has low power consumption and is suitable for customizable design and performance options. The electroactive polymer module 200 represents an electroactive polymer module developed by Artificial Muscle, Inc. of Sunnyvale, California.

  Still referring to FIG. 9, many of the design variables (eg, thickness, footprint) of the electroactive polymer module 200 may be fixed depending on the needs of the module integrator and other variables (eg, dielectric layers). , The operating voltage) may be limited by cost. The structure of the actuator (assignment of rigid support structure and footprint to active dielectric) does not significantly affect the cost, so that the application example in which the module 200 is integrated with the headphone device as shown in FIGS. It can be a reasonable way to match the performance of the electroactive polymer module 200.

  Computer modeling techniques can be used to evaluate the following advantages of different actuator structures: (1) handset / user system mechanism; (2) actuator performance; and (3) user sensation. These three elements provide a computerized process that evaluates the capabilities of the candidate design and uses the evaluated capability data to select an electroactive polymer design suitable for mass production. The model predicts the ability of two types of effects: long effects (game and music) and short effects (key clicks). “Ability” is defined herein as the maximum sensation that a module can produce during operation. For such a computerized process for evaluating candidate design capabilities, see the same applicant's International PCT Patent Application No. PCT / US2011 / 000289 “ELECTROACTIVE POLYMER APPARATUS AND TECHNIQUES FOR QUANTIFYING CAPABILITY THEREOF” (filed February 15, 2011). The entire disclosure of this application is incorporated herein by reference.

  FIG. 10 is a schematic diagram illustrating an electroactive polymer system 300 designed to explain the operating principle of an electroactive polymer module. The electroactive polymer system 300 includes a power supply 302, which is illustrated as a low voltage direct current (DC) battery for purposes of illustration and is electrically connected to the electroactive polymer module 304. According to the present disclosure, a power supply (VBatt) represents the output of an audio signal source configured to generate a low frequency audio signal, for example, less than about 200 Hz, and in one embodiment between about 2 Hz and about 200 Hz. Here, the term “about” represents ± 10%. The electroactive polymer module 304 includes a thin elastomeric dielectric element 306 disposed (eg, sandwiched) between two conductive electrodes 308A, 308B. The conductive electrodes 308A, 308B are stretchable (eg, conformable) and may be printed on the top and bottom of the elastomeric dielectric element 306 using any suitable technique (eg, screen printing). The electroactive polymer module 304 is activated by closing the switch 312 and connecting the battery 302 (eg, signal source) to the actuator circuit 310. Actuator circuit 310 converts the low DC voltage VBatt signal into a higher DC voltage Vin signal suitable for driving electroactive polymer module 304. In accordance with the present disclosure, additional circuitry may be disposed within the opening 124 defined by the housing 118, which circuit transmits a low voltage, low frequency audio signal from an audio signal source to the electroactive polymer actuator 122 ( 6 to 8) are configured to convert to a higher voltage signal suitable for driving. Returning to FIG. 10, when the voltage Vin is applied to the conductive electrodes 308A and 308B, the elastomeric dielectric element 306 contracts in the vertical direction (V) and expands in the horizontal direction (H) under a static voltage. To do. The contraction and expansion of the elastomeric dielectric element 306 can be utilized as an operation. The amount of movement or displacement is proportional to the input voltage Vin. The motion or displacement can be amplified by a suitably configured electroactive polymer actuator, as described below with reference to FIGS. 11A, 11B, and 11C.

  11A, 11B, and 11C are diagrams illustrating three possible configurations of electroactive polymer actuator arrays 400, 420, and 440, in accordance with various embodiments. Various embodiments of the electroactive polymer actuator array may comprise any suitable number of bars, depending on the application and the physical space constraints of the application. Additional bars can be used to enhance realistic sound reproduction vibrations that the user can immediately sense to provide additional displacement. The electroactive polymer actuator arrays 400, 420, 440 may be connected to the drive electronics of the actuator control circuit via flexible cables 402, 422, 442.

  FIG. 11A shows an example of a 1 bar electroactive polymer actuator array 400. The 1 bar electroactive polymer actuator array 400 includes a fixed plate 404, an output bar 406, and an elastomeric dielectric element 408 coupled to the fixed plate 404.

  FIG. 11B shows an example of a three bar electroactive polymer actuator array 420 comprising three bars 424, 426, 428 coupled to a fixed frame 430. Each pair of bars is separated by a divider 432. Each of the three bars 424 426 428 includes an output bar 434 and an elastomeric dielectric element 436. The 3-bar electroactive polymer actuator array 420 amplifies the sliding motion compared to the 1-bar electroactive polymer actuator array 400 of FIG. 11A.

  FIG. 11C shows an example of a 6 bar electroactive polymer actuator array 440 comprising 6 bars 444, 446, 448, 450, 452, 454 coupled to a fixed frame 456, where each pair of bars is a partition 458. Separated by Each of the six bars 444, 446, 448, 450, 452, 454 includes an output bar 460 and an elastomeric dielectric element 462. The 6 bar electroactive polymer actuator array 440 amplifies the force on the sliding surface compared to the 1 bar electroactive polymer actuator array 400 of FIG. 11A and the 3 bar electroactive polymer actuator array 420 of FIG. 11B.

  The electroactive polymer actuator arrays 400, 420, 440 shown in FIGS. 11A-11C may be integrated into various electroactive polymer actuators to achieve a desired effect in a headphone application. For example, in one embodiment, the electroactive polymer actuator array may be configured to be attached to the inner surface of the housing 118 shown in FIGS. In the embodiment illustrated in FIGS. 6-8, the electroactive polymer actuator array 128 is integrated with the electroactive polymer actuator 122 to implement sensory enhancement headphones.

  FIG. 12 is an exploded view illustrating one embodiment of an electroactive polymer module 500 with a flex suspension system 502 that can be used with sensory enhancement headphones. An example of a flex suspension system that can be used in the disclosed embodiment is the same applicant's International PCT Patent Application No. PCT / US2012 / 021506 “ELECTROACTIVE POLYMER FLEXURE APPARATUS, SYSTEM, AND METHOD” (filed Jan. 17, 2012). No. 61 / 433,655 “SLIDING MECHANISM AND AMI ACTUATOR INTEGRATION” (filed on Apr. 21, 2011) under 35 USC 119 (e). 61 / 477,680 “Z-MODE BUMPERS” (filed on April 21, 2011), 61 / 493,123 “FLEXURE SYSTEM DESIGN” (filed on June 3, 2011), 61/493 588, “ELECTRICAL BATTERY CONNECTION” (filed on June 6, 2011) and 61 / 494,096 “BATTERY VIBRATOR FLEXURE WITH METAL BATTERY CONNECTOR FLEXURE” (20 Claiming the priority of June 7, 1 filed). The entire disclosures of which are incorporated herein by reference. In one embodiment, the flex tray 504 defines an opening 510 for receiving an electroactive polymer actuator 506 (shown in exploded view) therein. One side of the electroactive polymer actuator 506 may be attached to the bottom of the flex tray 504 and the opposite side of the actuator 506 may be coupled to the mass 508. The electroactive polymer actuator 506 and the mass 508 have dimensions that just fit within the opening 510 defined by the tray 504. As shown in FIG. 12, the actuator 506 comprises two sets of electroactive polymer actuator arrays 512, 512 '. In another embodiment, one electroactive polymer actuator array 512 may be used, and in another embodiment, more than two sets of electroactive polymer actuator arrays 512, 512 ' 506 may be used. As shown, the first and second sets of electroactive polymer actuator arrays 512, 512 ′ respectively couple the first set of electroactive polymer actuator arrays 514B, 514B ′ to the bottom of mass 508. For this purpose, output bar adhesive layers 514A and 514A ′ are provided. Interframe adhesive layers 514C, 514C 'are used to couple the first set of electroactive polymer actuator arrays 514B, 514B' to the second set of electroactive polymer actuator arrays 514D, 514D '. Base frame adhesive layers 514E, 514E 'couple the second set of electroactive polymer actuator arrays 514D, 514D' to the mounting surface 516 in tray 504. As shown in FIG. 12, electroactive polymer actuator 506 comprises two 3-bar electroactive polymer actuator arrays. In other embodiments, any suitable number of electroactive polymer actuator arrays with any suitable number of bars may be used, as will be described later. Although not shown in FIG. 12, either the mass 508 or the tray 508 may be physically and / or electrically coupled to the printed circuit board, for example, with a flexible cable connector. The flex suspension system 502 can be utilized to implement an acoustic headphone system, as described in detail below. Further details of the flex suspension system 502 will be described later with reference to FIGS.

  So far, various integrated devices with electroactive polymer feedback modules that can be used in various embodiments of the electroactive polymer actuators shown in FIGS. 6-8 have been generally described. Below, FIGS. 13-16 which show one Embodiment of the electroactive polymer actuator 122 are demonstrated. In FIG. 13, portions of the housing 118 and the ear covering cushion 108 of the ear cup 102 are not shown to more clearly show the elements of the electroactive polymer actuator 122 and the speaker 120, according to one embodiment. In the illustrated embodiment, the electroactive polymer actuator 122 includes a stand-alone tray 126 (eg, in another embodiment, the tray 126 may be replaced with a flex suspension system), An opening 136 is defined for holding the mass 130 and the electroactive polymer actuator array 128 (shown in FIGS. 14-15) below the mass 130. The tray 126 includes a peripheral surface 134 for attaching the electroactive polymer actuator 122 to the inner wall 132 (FIGS. 7-8) of the housing 118. The tray 126 includes a slot 138 that receives a flexible cable for connecting the electroactive polymer actuator array 128 to the actuator circuit.

  14 removes the mass 130 (FIG. 13) in addition to portions of the housing 118 and ear cover cushion 108 of the ear cup 102 to illustrate the underlying electroactive polymer actuator array 128, according to one embodiment. FIG. 3 is a diagram of an electroactive polymer actuator 122. As shown in FIG. 14, the electroactive polymer actuator array 128 is disposed in the tray 126. FIG. 15 illustrates the electroactive polymer actuator of FIG. 14 with the tray removed, according to one embodiment. 14-15, the electroactive polymer actuator array 128 includes a rigid frame and partition 142 that separates the electrode 148 and the elastomeric dielectric element 146. An adhesive layer 144 is provided on the upper surface of the electrode 148 to adhere and attach the upper surface of the electroactive polymer actuator array 128 to the lower surface of the mass 130. The electroactive polymer actuator array 128 includes three sets of electrodes 148 and an elastomeric dielectric element 146 and may be referred to as a three bar cartridge.

  16 illustrates the electroactive polymer actuator 122 of FIG. 15 with the mass 130 and the cartridge portion of the electroactive polymer actuator array 128 removed to show only the tray 126 and the lower rigid frame element 142, according to one embodiment. It is.

  17 and 18 are a top view and a cross-sectional view at section line 18-18 illustrating an electroactive polymer actuator 600, according to one embodiment. The electroactive polymer actuator 600 includes a bent suspension system 622 and can be used in the headphones 100 instead of the electroactive polymer actuator 122 shown in FIGS. 1, 6 to 8, and FIGS. 13 to 16. The bent suspension system 622 includes a suspension tray 608, a mass 602, and an electroactive polymer actuator array 624 (shown in FIG. 18). As shown in FIG. 18, the electroactive polymer actuator 600 has a top plate 610 disposed on a flex suspension system 622 and a frame and partition 614 that separates the three sets of output bars 616 and elastomeric dielectric elements 618. A base plate 612. Accordingly, electroactive polymer actuator 600 is a three bar inertial electroactive polymer module. The electroactive polymer actuator 600 comprises an electroactive polymer actuator disposed within the suspension tray 608 of the flex suspension system 622. The suspension tray 608 includes suspensions or bending arms 604 and 606. The electroactive polymer actuator 600 defines a vibration plane XY. The bent suspension system 622 restricts movement mainly in one direction (for example, the direction along the Y-axis indicated by the arrow 620). Limiting movement in the Z direction helps to maintain the gap necessary for free movement in the Y direction. When a voltage from a low frequency audio signal is applied to the electroactive polymer actuator 600, the suspension tray 608 operates substantially along the Y axis, as indicated by arrow 620, along the X and Z axes. Operation is substantially minimized. Thus, the electroactive polymer actuator 600 with the flex suspension system 622 substantially reduces or eliminates undesirable acoustic effects. The flex suspension system 622 may be utilized to create acoustic effects and intentionally add artifacts to the soundtrack.

  In one embodiment, the bent suspension system 622 includes at least one bend coupled to the electroactive polymer actuator array 624, the bend being on the first and second electrodes in the elastomeric dielectric element 618. When a voltage is applied, the flex suspension system 622 allows it to move in a predetermined direction. In one embodiment, the flex suspension system 622 includes at least one movement stop to limit movement of the suspension tray 608 in a predetermined direction. In one embodiment, the suspension tray 608 includes at least one bent arm 604, 606. In one embodiment, the flex tray 608 includes at least one movement stop to limit movement of the flex suspension system 622 in a predetermined direction. In one embodiment, at least one of the bending arms is integrally formed with the suspension tray 608.

  19-27 illustrate one embodiment of an electroactive polymer actuator 700 that includes a flex suspension system 722 similar to the flex suspension system 622 shown in FIGS. FIG. 19 is a perspective view illustrating an electroactive polymer actuator 700 and FIG. 20 is a rear view illustrating the actuator, according to one embodiment. FIG. 21 is a cross-sectional view of electroactive polymer actuator 700 at section line 21-21, and FIG. 27 is a cross-section of electroactive polymer actuator 700 at section line 27-27 shown in FIG. FIG. Here, according to FIGS. 19-21 and 27, in addition to the flex suspension system 722, in one embodiment, the electroactive polymer actuator 700 includes an upper plate 710, a base plate 712, and first and second conductive materials. A slot 726 for receiving a flexible cable 728 for electrically connecting the electroactive polymer actuator array 724 to the electronic drive circuit 740 via elements 736A, 736B. Base plate 712 includes an opening 730 that exposes a portion of output bar 716 of electroactive polymer actuator array 724.

  FIG. 21 illustrates a mass 702 and a first adhesive layer 732 disposed between the electroactive polymer actuator array 724 and the base plate 712 to attach the electroactive polymer actuator 700 to the base plate 712 in accordance with one embodiment. FIG. A second adhesive layer 734 is disposed between the mass 702 and the electroactive polymer actuator array 724 and attaches the electroactive polymer actuator array 724 to the mass 702 by attachment.

  FIG. 22 is a perspective view of the electroactive polymer actuator 700 with the top plate 710 removed to show the mass 702 located in the suspension tray 708 of the flex suspension system 722, according to one embodiment. The suspension tray 708 includes first and second suspension arms 704 and 706. As described in connection with FIGS. 17 and 18, suspension arms 704, 706 formed in the suspension tray 708 allow the flex suspension system 722 to move in a predetermined manner. For example, the suspension arms 704 and 706 of the bent suspension system 722 restrict the movement of the mass body 702 in the XY plane mainly in the direction along the Y axis, as indicated by an arrow 720. Limiting movement in the Z direction helps to maintain the gap necessary for free movement in the Y direction. Thus, when a higher voltage is applied to the electroactive polymer actuator 700 from the low frequency audio signal, the suspension tray 708 moves substantially in the direction of motion indicated by the arrow 720 along the Y axis.

  23 is a perspective view of the electroactive polymer actuator 700 of FIG. 22 with the mass 702 removed to show the adhesive layer 734 disposed over the electroactive polymer actuator array 724, according to one embodiment. The adhesive layer 734 adheres and bonds the electroactive polymer actuator array 724 to the lower surface of the mass 702. The electroactive polymer actuator array 724 further includes a frame and divider 714 that separates three sets of separate output bars 716 and elastomeric dielectric elements 718. Since the electroactive polymer actuator array 724 comprises three bars, it may be referred to as a three bar inertial electroactive polymer module without limitation.

  FIG. 24 is a perspective view of the electroactive polymer actuator 700 of FIG. 23 with the flex tray 708 removed to better illustrate the base plate 712 and the 3-bar electroactive polymer actuator array 724 in accordance with one embodiment. As shown in FIG. 24, the electroactive polymer actuator array 724 includes a frame and partition 714, an output bar 716, an elastomer dielectric element 718, and an adhesive layer 734 disposed on the output bar 716.

  FIG. 25 is a perspective view of the electroactive polymer actuator 700 of FIG. 24 with the electroactive polymer actuator array 724 removed to show the base plate 712 and the adhesive layer 732, according to one embodiment. Base plate 712 includes an opening 730 and an adhesive layer 732 is disposed between base plate 712 and electroactive polymer actuator array 724. The first and second conductors 736A and 736B of the flexible circuit 728 are electrically connected to the corresponding first and second terminals 738A and 738B.

  26 is a perspective view of the electroactive polymer actuator 700 of FIG. 25 with the adhesive layer 732 and the flex circuit 728 removed to show the base plate 712 and the opening 730, according to one embodiment.

  FIGS. 28-31 illustrate one embodiment of an electroactive polymer actuator 800. In one embodiment, the electroactive polymer actuator 800 includes a tray 822, a mass 802, and a slot 826 formed in the tray 822. Slot 826 is sized to receive a flexible cable (not shown) for electrically connecting electroactive polymer actuator array 824 to an electronic drive circuit. FIG. 30 is a diagram illustrating a base portion of a tray 822 with the electroactive polymer actuator array 824 removed, according to one embodiment. The base portion of the tray 822 includes an opening 830 that exposes the output bar 816 of the electroactive polymer actuator array 824. Mass 802 is adhered to electroactive polymer actuator array 824 by an adhesive layer 834 disposed therebetween. The electroactive polymer actuator 800 defines a vibration plane indicated by an XY plane. The tray 822 restricts movement in one direction mainly along the Y axis, as indicated by an arrow 820. Limiting movement in the Z direction helps to maintain the gap necessary for free movement in the Y direction. Thus, when a higher voltage is applied to the actuator 800 from the low frequency audio signal, the tray 822 moves substantially in the direction of motion indicated by the arrow 820 along the Y axis.

  FIG. 29 is a perspective view of the electroactive polymer actuator 800 of FIG. 28 with the mass 802 removed to show the adhesive layer 834, according to one embodiment. As shown, the adhesive layer 834 is disposed on the electroactive polymer actuator array 824, and the mass body 802 is disposed thereon. The electroactive polymer actuator array 824 is bonded to the lower surface of the mass 802 with an adhesive layer 834. Electroactive polymer actuator array 824 further includes a frame and divider 814 that separates three sets of separate output bars 816 and elastomeric dielectric elements 818 of electroactive polymer actuator array 824. Since the electroactive polymer actuator array 824 comprises three bars, it may be referred to as a three bar electroactive polymer module without limitation. FIG. 31 is a perspective view illustrating a portion of an electroactive polymer actuator array 824 of an electroactive polymer actuator 800, according to one embodiment.

  32 and 33 are graphs 900, 950 of test data showing the frequency response of each of the two types of electroactive polymer actuators with frequency (Hz) on the horizontal axis and stroke (mm) on the vertical axis. It is. Graph 900 shown in FIG. 32 shows electroactive polymer actuator 122 (FIGS. 6-8 and 13), and electroactive polymer actuator 800 that moves the sprung mass, primarily utilizing the operation of the electroactive polymer actuator array. FIG. 28 shows a frequency response curve of an electroactive polymer actuator without a bent suspension system and a sprung mass, such as (FIG. 28). At some frequencies (especially 20 Hz to 50 Hz), the sprung mass moves freely in all directions and swings because there is no restriction or support in undesired directions. This phenomenon appears as a displacement in the desired direction and thus distortion 902, 904 in the desired sensation. A graph 950 shown in FIG. 33 shows a frequency response curve of an electroactive polymer actuator that uses a flex suspension system, such as the flex suspension systems 622, 722 of the actuators 600, 700 shown in FIGS. Regions 952 and 954 clearly show that undesired strains have been successfully eliminated by the flex suspension system 622,722.

  34 to 40 show an embodiment of an ear cup 1000 that can be used with the sensory enhancement headphones 100 shown in FIG. 34 and 35 show a perspective cross-sectional view of the ear cup 1000 and FIG. 36 shows a front cross-sectional view of the ear cup, according to one embodiment. Referring now specifically to FIGS. 34-36, in one embodiment, the right ear cup 1000 includes an ear covering cushion 1008 and a housing 1018, which includes a speaker 1020 and an electroactive polymer actuator 1022. Defines an opening 1024 suitable for mounting therein. In the embodiment shown in FIGS. 34-36, the electroactive polymer actuator 1022 may be referred to as an electroactive polymer module. In particular, in the embodiment shown in FIGS. 34-36, the electroactive polymer actuator 1022 may be referred to as a 3-bar inertial electroactive polymer module without limitation. As shown in the figure, the speaker 1020 can be attached immediately behind the perforated speaker grill 1012. However, in other embodiments, the position of the speaker 1020 may be different. In one embodiment, the actuator 1022 comprises a stand-alone tray 1026 configured to receive an electroactive polymer actuator array 1028 and a mass 1033 therein. The electroactive polymer actuator 1022 is attached to the acoustic cavity 1050, which is provided immediately behind the speaker 1020. In another embodiment, the actuator 1022 includes a flex suspension system, such as the flex suspension system 622, 722 of each of the actuators 600, 700 shown in FIGS. 17-19, for example, at a lower frequency (eg, less than 200 Hz). ) May be mechanically corrected. The actuator 1022 may further comprise an electroactive polymer actuator array 1028 and a mass body 1030.

  FIGS. 37-41 show various elements of the ear cup 1000 with other elements removed to show the underlying structure, according to one embodiment. Accordingly, FIG. 37 illustrates one embodiment of an ear cup 1000 with the ear covering cushion 1008 and housing 1018 removed to expose the lower stand-alone tray 1026 attached to the acoustic cavity 1050 on the back side of the speaker 1020. It is.

  38 illustrates the ear cup 1000 of FIG. 37 with the stand-alone module housing 1026 removed to expose the electroactive polymer actuator array 1028, according to one embodiment. The electroactive polymer actuator array 1028 includes a rigid frame and divider 1042 that separates the output bar 1048 and the elastomeric dielectric element 1046. An adhesive layer 1044 is provided on the output bar 1048 to adhere the electroactive polymer actuator array 1028 to the stand-alone tray 1026. The mass body 1030 is suspended from a bent portion (not shown) attached to the stand-alone tray 1026. A second adhesive layer (not shown) may be provided to adhere the stand-alone tray 1026 to the acoustic cavity 1050.

  FIG. 39 shows the ear cup 1000 of FIG. 38 with the electroactive polymer actuator array 1028 removed to expose the mass 1030, according to one embodiment. FIG. 40 shows the ear cup 1000 of FIG. 39 with the mass body 1030 removed, and FIG. 41 is a bottom view of the acoustic cavity 1050 showing the speaker 1020 mounted therein, according to one embodiment.

  So far, various electroactive polymer headphone embodiments have been described that include mechanical techniques for reducing acoustic noise. The following describes an electronic method for acoustic noise reduction that can be incorporated into any of the electroactive polymer actuator embodiments described herein. In the following, embodiments of electronic acoustic noise reduction techniques that use non-linear inverse transformation to remove undesirable acoustic artifacts will be described. First, FIG. 42 will be briefly described. FIG. 42 illustrates one embodiment of sensory enhancement headphones 1100 comprising an electroactive polymer actuator 1102 housed in a first housing portion 1104 of an ear cup 1110. Also shown is a circuit board 1106 comprising an electronic circuit for driving the electroactive polymer actuator 1102 at a low audio frequency and an electronic circuit for reducing undesirable acoustic noise. The circuit board 1106 may be attached to the back side of the electroactive polymer actuator 1102. The entire assembly of electroactive polymer actuator 1102 and circuit board 1106 may be disposed between first housing portion 1104 and second housing portion 1108.

  FIG. 43 is a block diagram 1200 illustrating an electronic circuit for generating a low frequency audio signal for driving an electroactive polymer actuator and reducing undesirable acoustic noise, according to one embodiment. Various signal conditioning, amplification, compensation, and drive circuits are also implemented. In particular, an analog audio signal module 1202 receives an analog audio signal from a source of a differential amplifier. In one embodiment, the differential amplifier is any suitable integrated, such as, for example, an AD822 single power rail-to-rail low power field effect transistor input operational amplifier or any suitable equivalent available from Analog Devices, Inc., Norwood, Massachusetts. It may be implemented with a circuit amplifier.

  An automatic gain control module 1204 receives the output signal from the analog audio signal module 1202 and provides automatic gain control, eg, 0 dB to 20 dB (or any suitable gain). In one embodiment, the automatic gain control module 1204 may include, for example, MAX9814 (a microphone amplifier with automatic gain control and a low noise microphone) available from Maxim Integrated Products, Inc., Sunnyvale, California, or any suitable equivalent, such as: It may be implemented with any suitable integrated circuit amplifier. In one embodiment, the automatic gain control module 1204 is configured to control the amount of vibration to drive the electroactive polymer actuator in each of the earcups in a manner different from the actual audio acoustic signal volume. ing. The vibration level for driving the electroactive polymer actuator in each ear cup is different from the actual audio sound signal volume, but the vibration level gain is correlated or based on the audio sound level gain. In various embodiments, the relationship between vibration level gain and audio sound level gain may be linear or non-linear, depending on the implementation of the specific design. In one embodiment, the relationship between gains is non-linear to approximate a non-linear function (sine function, square root function, logarithmic function, exponential function, etc.). In the illustrated embodiment, the relationship between vibration level gain and audio sound level gain is a non-linear function approximating a square root function. In other words, the vibration level gain is approximately correlated with the square root of the audio sound level gain. Thus, the vibration of the electroactive polymer actuator tracks the input low frequency sound and gives a low frequency sound sensation without producing high pressure sound waves that can be dangerous to the eardrum.

  In one embodiment, the vibration level gain approximates the square root of the audio sound level gain as shown in Table 1.

  A signal is sent from the automatic gain control module 1204 to the low frequency digital filter module 1206. The low frequency digital filter module 206 may be implemented using any suitable circuit technology and may comprise a microcontroller and programmable gate array circuit, among other digital or analog processing circuit elements. In one embodiment, the low frequency digital filter module 1206 is any suitable programmable system, such as, for example, a CY8C29466 programmable system-on-chip controller or any suitable equivalent available from Cypress Semiconductor, Inc., San Jose, California. May be implemented.

  A low frequency amplifier module 1208 amplifies the output of the low frequency digital filter module 1206 and the output is sent to a programmable gate array circuit. In one embodiment, the low frequency amplifier module 1208 may be any suitable, such as MAX9618 (low power zero drift op amp) or any suitable equivalent available from Maxim Integrated Products, Inc., Sunnyvale, California. It may be implemented using an integrated circuit amplifier.

  The output of the low frequency digital filter 1206 is fed into a non-linear inverse transform circuit (square root circuit), such as an inverse polynomial circuit 1210, which reverses unwanted distortion of the audio signal used to vibrate the electroactive polymer actuator. Provide electronic audio signal correction for removal. In other words, the inverse polynomial circuit 1210 linearizes the electroactive polymer actuator by approximating an inverse function, for example. In various embodiments, the inverse polynomial circuit 1210 may be implemented using integrated circuits, programmable circuits, piecewise linear circuits, and / or any combination thereof. In one embodiment, a piecewise linear circuit can be used to approximate a non-linear function (sine function, square root function, logarithmic function, exponential function, etc.). The quality of the approximation depends on the number of sections used by the piecewise linear circuit and the method used to determine the sections. In general, there are two ways to build piecewise linear circuits: (1) switch sections using a non-linear voltage divider with a diode (or transistor), and (2) output a series of saturated amplifiers. Sum up. Both of these methods are available and technically equivalent, but each has advantages and disadvantages.

  The diode-based method has the advantage of simplicity, but has the disadvantages of temperature dependence on the switching threshold and relatively slow response. The saturated amplifier method has the disadvantage of being complex, but has the advantage of being fast and with minimal temperature dependence on the threshold. In various embodiments, the inverse polynomial circuit 1210 may be implemented as a compression circuit or decompression circuit, with each circuit having a different circuit topology. The compression circuit compresses the dynamic range of the input signal, and the expansion circuit expands the dynamic range. Examples of compression circuits include square root circuits, logarithmic circuits, and sine circuits, generally using non-linear voltage divider techniques. An example of the extension circuit is an exponential function. In another embodiment, a compression circuit and an expansion circuit may be used together, for example, to implement an inverse polynomial circuit 1210 for linearizing an electroactive polymer actuator. One embodiment of a piecewise linear circuit that approximates the inverse square root function using diode switching is described in detail below with reference to FIG.

  The output of the inverse polynomial circuit 1210 is supplied to a high voltage amplifier 1212 for amplification to a level sufficient to drive the electroactive polymer actuator module. In general, the voltage required to drive an electroactive polymer actuator module can range from several hundred volts (V) to several thousand volts (kV). The nominal drive voltage is about 1 kV. The left channel output 1214L of the high voltage amplifier 1212 is fed to the left reflective actuator and mass 1216L, eg, an electroactive polymer actuator located in the left ear cup of the headphones. The right channel output 1214R of the high voltage amplifier 1212 is fed to the right reflective actuator and mass 1216R, eg, an electroactive polymer actuator located in the right ear cup of the headphones. In one embodiment, a single layer actuator can be enhanced using a square root circuit with sensory enhancement headphones with an electroactive polymer actuator. For example, a non-linear control technique may be used with a multiphase actuator.

  In one embodiment, the electronic circuit comprises a visual feedback display module 1218. In this embodiment, a blue display (eg, a light emitting diode or LED) indicates the audio signal. A green display indicates a processed signal. Orange / red display indicates mixed and high voltage signals. As will be appreciated by those skilled in the art, any combination of desired colors can be used to provide visual feedback.

  FIG. 44 is a graph illustrating harmonic distortion measurements 1300 without using the inverse polynomial circuit 1210 (eg, “inverse square root circuit”) shown in FIG. 43, according to one embodiment. The lower curve 1302 is an acceleration waveform measured at 100 Hz without the square root circuit 1210, and the upper curve 1304 is a Fourier transform showing the second harmonic 1306.

  FIG. 45 is a graph illustrating measured harmonic distortion values 1350 when using the inverse polynomial circuit 1210 (“square root circuit”) shown in FIG. 43, according to one embodiment. A lower curve 1352 is an acceleration waveform measured at 100 Hz when the square root circuit 1210 is used, and an upper curve 1354 is a Fourier transform showing a significantly reduced second harmonic 1356.

  FIG. 46 illustrates one embodiment of the inverse polynomial circuit 1210 of FIG. 43 utilizing a piecewise linear circuit that approximates the inverse square root function using diode switching. As described in connection with FIG. 43, another non-linear circuit topology may be used to implement a linearization function that linearizes the electroactive polymer actuator, and the topology described with respect to FIG. 46 is only an example. . Thus, the inverse polynomial circuit embodiments should not be limited in this regard. In the embodiment shown in FIG. 46, the inverse polynomial circuit 1210 includes a voltage-to-current converter circuit 1220, a piecewise linear circuit 1230 using a diode switching topology, and a final gain amplifier 1240. For example, as shown in FIG. 43, the output voltage Vo is supplied to the high voltage amplifier 1212.

  The voltage-to-current converter circuit 1220 uses the first amplifier A1 and the resistors R1 to R4 to generate a current i that is proportional to the input voltage Vin from the low-frequency digital filter module 1206 of FIG. The current i is supplied to a piecewise linear circuit 1230, which is configured to approximate an inverse square root function (current to voltage) using R5 to R15 and diodes D1 to D5. The final gain amplifier 1240 includes resistors R16-R17 and a second amplifier A2, which sets the final scaling (at R16 and R17), which can be any value between 1 and 100. Usually, it will be between 1 and 2.

  In the illustrated embodiment, the piecewise linear circuit 1230 comprises five sections that are switched depending on the current and the resulting node voltage vn. Each segment has a breakpoint voltage that approximates a different slope based on the vn input voltage range. For example, the first segment is equal to VA plus the diode voltage drop at D1. A first breakpoint voltage V1 is provided. Similarly, the second segment has a second breakpoint voltage V2 equal to VB plus the diode voltage drop at D2, and so on up to and including the fifth segment. Has a fifth breakpoint voltage V5 equal to VE plus the diode voltage drop at D5. Each section has a different slope based on the parallel combination of resistors R5-R15. When switched to each segment, the slope changes so that the node voltage vn approximates the inverse square root function depending on the value selected for the resistor. Piecewise linear circuit 1230 may implement a square root function or other non-linear function depending on the selected resistance value. Amplifiers A1 and A2 may be any suitable integrated circuit amplifier such as, for example, an AD823 rail-to-rail FET input operational amplifier available from Analog Devices, Norwood, Mass., Or any suitable equivalent. In one embodiment, the voltage V + may be + 5V, for example.

  In one embodiment, resistors R1-R4 for implementing voltage-to-current converter circuit 1220, resistors R5-R15 for implementing piecewise linear circuit 1230, and a resistor for implementing final gain amplifier 1240. R16 to R17 are shown in Table 2. Resistor values may have different tolerances depending on the accuracy to be achieved and may be ± 10%, ± 5, ± 1, or may be adjusted to any suitable value Please understand that.

  47-54 are diagrams illustrating further details of the flex suspension system in accordance with the disclosed embodiments. 47 is a partial cutaway view of the electroactive polymer module 500 of FIG. 12 with a flex suspension system, according to one embodiment.

  48 is a schematic diagram illustrating one embodiment of the electroactive polymer module 500 of FIG. 12 with the flex suspension system 506 of FIGS. 12 and 47 with the flex tray 504 according to one embodiment. 47 and 48, the bending tray 504 includes a bending portion 570, movement stop portions 572 and 574, and a mass body 508 disposed in an opening defined by the bending tray 504. The bent portion 570 and the movement stop portions 572 and 574 may be formed on the bent tray 504 or may be provided as separate components. As described above, the flex tray 504 is coupled to the mounting surface 568, which serves as a mechanical foundation for the flex suspension system 502. The bends 570 located at one or more positions allow the bend tray 504 to vibrate in one or more operating directions. In the illustrated embodiment, the flex tray 504 includes four separate bends 570 that allow the flex tray 504 to operate in the X and Y directions. The bending tray 504 further includes an X-movement stop unit 572 and a Y-movement stop unit 574 in order to restrict movement or operation in a predetermined direction and prevent damage due to impact-type operation. X- and Y-movement stops 572, 574 are provided to limit the movement of the flex tray 504 in the X and Y directions, as described in detail below with reference to FIGS. The flex suspension system 502 can limit undesirable vibrations in undesired directions of motion.

  49 is a diagram 580 of oscillating motion in the X and Y axes to model the motion in the X and Y directions of the flex suspension system 502 shown in FIGS. 12 and 47-48, according to one embodiment. . 50 is a diagram 582 of an oscillating motion in the X and Z axes to model the motion in the X and Z directions of the flex suspension system 502 shown in FIGS. 12 and 47-48, according to one embodiment. . 12 and FIGS. 47 to 50, kfx = the combined stiffness in the X-axis direction of the bent portion 570 and electrical connection, kax = the active stiffness in the X-axis direction of the electroactive polymer actuator 506, kfz = the bent portion 570. And the composite stiffness in the Z-axis direction of the electrical connection, kaz = the stiffness in the Z-axis direction of the electroactive polymer actuator 506, mtray + mbatt = the total sprung mass consisting of the operating mass 508 and any other support structure.

X-axis compliance X-axis compliance is one factor to consider when evaluating the performance of the flex suspension system 502. The composite non-actuator stiffness (kfx) is preferably reduced as much as possible, for example, maintained below about 10% of the actuator stiffness (kax). Additional stiffness from the electrical interconnect is preferably taken into account for non-actuator stiffness calculations. The rigidity of the bent portion 570 in the X-axis direction provides appropriate operation control using the movement stop portions 572 and 574 appropriately.

Z-axis compliance Z-axis compliance is particularly suitable for touch surface (eg touch screen or touchpad) suspension applications and flex suspension systems 502 where unlimited X-axis motion of the assembly is preferably ensured during user input. Are preferably reduced as much as possible in order to reduce the displacement of dynamic mass due to gravity or user input. Ideally, the total stiffness in the Z-axis direction can exceed 300 times the total stiffness in the X-axis direction. If the negative Z direction (−Z direction) movement stop is not utilized, the bend 570 is preferably configured to withstand forces or impacts that may be experienced during removal of the mass 508.

If the Y-axis compliance bent portion 570 is appropriately designed, the compliance in the Y-axis direction becomes relatively small when the beam of the bent portion 570 is subjected to compression or tension. Any compliance in the Y axis direction is the result of buckling or stretching of the bend 570 which is undesirable in all situations. The amount of deviation in the Y-axis direction is preferably suppressed to a minimum in order to prevent damage to the bent portion 570 during operation, for example.

  Table 3 below provides the total stiffness of the bend based on the stiffness being 10% of the total stiffness of the electroactive polymer actuator 506, according to one embodiment, and the provided value is an approximate value It is an example.

  51 is a schematic diagram 584 illustrating movement stops 572, 574 of the flex tray 504 of the flex suspension system 502 shown in FIGS. 12 and 47-48, according to one embodiment. In the flex suspension system 502 shown in FIG. Are distributed. Bend 570 is shown symbolically for convenience and clarity. In one embodiment, stops 572, 574 are provided where possible, but allow free movement of dynamic mass under rated loads. Movement stops 572, 574 prevent excessive extension and damage of bend 570 and electroactive polymer actuator 506. The embodiment of the bend 570 presented herein is suitable for a movement stop built into all axes except the -Z direction where pulling out the mass 508 from the bend tray 504 can cause damage. A stop in the positive Z direction (+ Z direction) may be implemented using the actuator frame itself, which may be suitable to withstand industry standard drop tests, for example up to 1.5 m.

  Table 4 below shows the gaps between the flex tray stops 572, 574, according to one embodiment. The gaps A to F in Table 4 are examples of approximate values, and correspond to the gaps denoted by the same reference numerals in FIG.

  FIG. 52 is a schematic diagram 592 illustrating a beam model of a flex connection 594, according to one embodiment. The bent connecting portion 594 can be made of many materials. In one embodiment, the flex connection 594 may be made of plastic using, for example, a set of injection molded connections incorporated into the back case of the handset or the battery mounting frame of the tablet. In such an embodiment, the material of the flex connection may be a moldable plastic, such as, but not limited to, acrylonitrile-butadiene-styrene. For applications with higher Z-direction loading and / or limited space, the flex connection 594 may be made of a metal sheet and molded into a plastic frame. Alternatively, the entire stamped metal sheet subassembly may be manufactured and used in applications that require greater Z-direction loading. The rigidity of each connecting portion 594 can be calculated using, for example, the beam model shown in FIG. 52, and the deflection of the bending connecting portion 594 in the X and Z directions under the corresponding forces (Fx and Fz). (Dx and dz) are modeled.

  FIG. 53 is a diagram showing an embodiment of the bending tray 504 with the mass body 508 removed. The flex tray 504 includes a rigid outer frame 596 fixed to the mounting surface. In the illustrated embodiment, the rigid outer frame 596 may be secured to the mounting surface by fasteners inserted into one or more openings 598. Typical fasteners include screws, bolts, rivets and the like. As shown in FIG. 53, the flex tray 504 includes a flexure 570 that allows the flex tray 504 to move in the X and Y directions to provide the user's oscillating electroactive polymer stimulation. Also shown are an X movement stop 572 and a Y movement stop 574 to prevent excessive bending and damage of the bend 570 and the electroactive polymer actuator.

  FIG. 54 illustrates a portion 599 of one embodiment of the flex tray 504. A portion 599 shows the diameters φ1 and φ2 of the bent portion 570, the overlap distance d1 between the two bent portions, and the distance d2 between the curved portions of the bent portion 570. Table 5 provides reference design bend parameters according to one embodiment, and the values provided herein are examples of approximate values.

  The embodiments described herein are illustrative of the embodiments and functional elements, logic blocks, program modules, and circuits may be described in various other ways consistent with the described embodiments. It should be understood that it can be implemented. Further, the operations performed by such functional elements, logic blocks, program modules, and circuits may be combined and / or separated for a given implementation, with a greater or lesser number of components or programs It may be executed by a module. After reading this disclosure, it will be apparent to those skilled in the art that each embodiment described and illustrated herein can be derived from the features of any of several other embodiments without departing from the scope of this disclosure. It has individual components and features that can be easily separated or easily combined with such features. Any of the described methods may be performed in the order of the described steps, or in any other order that is logically possible.

  Several modules and / or blocks may be described by way of example, but it will be appreciated that a greater or lesser number of modules and / or blocks may be used and are within the scope of the embodiments. Moreover, various embodiments may be described in terms of modules and / or blocks for ease of description, and such modules and / or blocks may include one or more hardware components (eg, a processor, a digital signal processor, Programmable logic devices, application specific integrated circuits, circuits, registers), software components (eg, programs, subroutines, logic), and / or combinations thereof may be implemented.

  Numerous specific details are set forth in order to provide a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that the embodiments may be practiced without these specific details. In addition, in order to avoid obscuring the embodiments, detailed descriptions of well-known operations, components, and circuits are omitted. It should be understood that the specific structural and functional details disclosed herein are representative and do not limit the scope of the embodiments.

  Any reference to “one embodiment” or “an embodiment” means that the particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Please note that. The appearances of the phrase “in one embodiment” or “in an aspect” in the specification are not all referring to the same embodiment.

  Note that some embodiments are described using the expressions “coupled” and “connected” and their derivatives. These terms are not intended as synonyms for each other. For example, some embodiments may be described using the terms “connected” and / or “coupled” to indicate that two or more elements are in direct physical or electrical contact with each other. However, the term “coupled” can also mean that two or more elements are not in direct contact with each other but cooperate or interact with each other.

  It should be understood that those of ordinary skill in the art may embody the principles of the present disclosure and devise various configurations that fall within the scope thereof, even though not explicitly described or illustrated herein. In addition, all examples and conditionals described herein are intended primarily to assist the reader in understanding the principles described in this disclosure and the concepts that contribute to the promotion of technology, It should not be construed as limited to such specifically described examples and conditions. Moreover, all statements describing principles, embodiments, and embodiments and specific examples thereof are intended to include both structural and functional equivalents. In addition, such equivalents include both presently known equivalents and equivalents developed in the future, ie, any element developed that performs the same function, regardless of structure. Accordingly, the scope of the present disclosure is not intended to be limited to the exemplary embodiments and the embodiments shown and described herein. Rather, the scope of the present disclosure is embodied by the appended claims.

  The terms “a”, “an”, “the” (and above), and similar directives used in the context of this disclosure (particularly in the context of the following claims), and It should be interpreted as covering both the singular and the plural unless there is a clear contradiction to the context. The recitation of value ranges herein is intended only to serve as a convenient way of referring to each value within the range individually. Unless otherwise specified, each value is incorporated into the specification as if it were individually listed. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any examples or example words (eg, “such as”, “in that case”, “for example”) herein is merely intended to make the present invention easier to understand and is claimed. It is not intended to limit the scope of the invention. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention. Furthermore, it is noted that the claims may be written to exclude optional elements. This description is therefore intended to make use of exclusive terms, such as “only”, “only”, etc., in conjunction with the description of a claim element, or to make use of passive limitations. Is intended to serve as a preceding basis for

  Groupings of alternative elements or embodiments disclosed herein are not to be construed as limitations. The members of each group may be referenced and claimed individually or in any combination with other members of the group or other elements described herein. It is anticipated that one or more members within a group may be included in or excluded from the group for convenience and / or patentability reasons.

  While several features of the embodiments have been described above, many variations, substitutions, modifications, and equivalents will occur to those skilled in the art. Accordingly, the appended claims are intended to cover all modifications and variations that fall within the scope of the disclosed embodiments and appended claims.

Claims (17)

A sensory enhancement audio device,
An actuator system having a mechanical quality factor of less than about 10;
A circuit electrically connected to the actuator system,
The sensor-enhanced audio device, wherein the circuit generates a drive signal and operates the actuator system according to the drive signal.   The sensory enhancement audio device of claim 1, wherein the actuator system has a mechanical quality factor of about 1.5 to about 3.   3. The sensory enhancement audio device of claim 1 or claim 2, wherein the actuator system has a resonant frequency of about 50 to about 100 Hz.   4. The sensory enhancement audio device according to claim 1, wherein the actuator system includes at least one elastomeric dielectric element disposed between the first and second electrodes. 5. Sensory enhanced audio device with an electroactive polymer actuator array.   5. The sensory enhancement audio apparatus according to claim 1, wherein the drive signal is derived from an audio signal. 6.   The sensory enhancement audio device according to any one of claims 1 to 5, further comprising an acoustic radiator and an operation of the actuator system substantially in a direction perpendicular to the axis of the acoustic radiator. A sensory enhanced audio device comprising means for limiting.   7. The sensory enhanced audio device according to any one of claims 1 to 6, wherein the drive signal generated by the circuit is in a frequency range from about 2 Hz to about 200 Hz.   The sensory enhancement audio device according to any one of claims 1 to 7, further comprising a tray configured to accommodate the actuator system.   The sensory enhancement audio apparatus according to claim 1, further comprising a mass body coupled to the actuator system.   9. The sensory enhancement audio device according to claim 8, wherein the tray includes at least one opening.   9. The sensory enhanced audio device of claim 8, further comprising an acoustic cavity attached to the tray.   9. The sensory enhanced audio device of claim 8, wherein the tray comprises a suspension system for minimizing undesirable vibration modes by substantially limiting displacement in a single direction. . The sensory enhancement audio device according to claim 12, wherein the suspension system includes:
A suspension tray defining an opening for accommodating the mass body and the actuator system therein;
And at least one bending arm formed in the suspension tray,
The actuator system defines an oscillating surface defined by first and second axes, and is a sensory-enhanced audio device that allows movement in one direction mainly along the first axis.   14. A sensory enhancement audio device according to any one of claims 1 to 13, further comprising an inverse polynomial circuit for calculating a non-linear inverse transform to remove undesirable acoustic artifacts from the drive signal. Enhanced audio device.   15. The sensory enhancement audio device according to claim 1, wherein the audio device is a headphone.   16. Headphones according to claim 15, comprising at least one ear cup with the actuator system.   16. A sensory enhanced audio device according to any one of the preceding claims, wherein the intensity of the effect produced by the operation of the actuator system is controlled independently of the intensity of the audio signal. Sensory enhancement audio device.

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