Transparent speaker for displays, windows, and lenses

A transducer is described that includes a substrate configured to be deposited on a solid object, and a transparent medium coupled to the substrate and configured to oscillate at a pre-selected frequency upon receipt of an electrical excitation or a mechanical excitation and to provide a first acoustic wave. The transducer also includes an actuator configured to receive an electrical power, and to provide the electrical excitation or the mechanical excitation to the transparent medium, wherein at least a portion of the solid object is viewable through the transparent medium, and the first acoustic wave is at least partially transmitted through an interface of the transparent medium. A system and a non-transitory, computer-readable medium storing instructions to cause the system to perform a method to use the transducer for generating acoustic waves in a transparent medium are also disclosed.

BACKGROUND

Field

Embodiments as disclosed herein are related to the field of transparent acoustic transducers for use in optical components and devices. More specifically, embodiments as disclosed herein are related to transparent acoustic transducers for use in displays, windows, lenses, for aesthetically pleasing results on opaque containers and boxes, and for use in vehicles.

Related Art

Some applications use transparent membranes to activate acoustic modes in flat screen displays to generate audio signals accompanying the image display. However, the amplitude of the oscillations of the flat screen necessary to produce a loud enough audio signal tends to interfere with the quality of the image display, especially for low acoustic frequency having long standing wavelengths on the display. Moreover, the need for actuators capable of operating at high voltages, especially at the higher frequencies of the audible spectrum (let alone ultrasound applications), hinders the applicability of such techniques in compact devices (e.g., smart frames and mixed reality headsets).

SUMMARY

In a first embodiment, a transducer is described that includes a substrate configured to be deposited on a solid object, and a transparent medium coupled to the substrate and configured to oscillate at a pre-selected frequency upon receipt of an electrical excitation or a mechanical excitation and to provide a first acoustic wave. The transducer also includes an actuator configured to receive an electrical power, and to provide the electrical excitation or the mechanical excitation to the transparent medium, wherein at least a portion of the solid object is viewable through the transparent medium, and the first acoustic wave is at least partially transmitted through an interface of the transparent medium.

In a second embodiment, a device is described that includes a frame, a display mounted on the frame, the display comprising a substrate configured to be deposited on a solid object, and a power circuit configured to provide an electrical power. The device also includes an actuator configured to receive the electrical power, and to provide an electrical excitation or a mechanical excitation, and a transducer. The transducer includes a transparent medium coupled to the substrate and configured to oscillate at a pre-selected frequency in response to the electrical excitation or mechanical excitation, to provide a first acoustic wave, wherein at least a portion of the solid object is viewable through the transparent medium, and the first acoustic wave is at least partially transmitted through an interface of the transparent medium.

In yet another embodiment, a non-transitory, computer-readable medium stores instructions which, when executed by a processor, cause a computer to perform a method. The method includes filtering an electrical power to an electrode coupled to a transparent medium in a transducer to select a pre-determined frequency for an electrical excitation or a mechanical excitation of the transparent medium. The method also includes providing the electrical excitation or the mechanical excitation to generate a propagating acoustic wave from an interface in the transparent medium at the pre-determined frequency, directing the propagating acoustic wave in a pre-selected direction, and receiving an incoming propagating acoustic wave from the pre-selected direction in the interface of the transparent medium.

A system is also described. The system includes a means for storing instructions and a means for executing the instructions to cause the system to perform a method. The method includes filtering an electrical power to an electrode coupled to a transparent medium in a transducer to select a pre-determined frequency for an electrical excitation or a mechanical excitation of the transparent medium. The method also includes providing the electrical excitation or the mechanical excitation to generate a propagating acoustic wave from an interface in the transparent medium at the pre-determined frequency, directing the propagating acoustic wave in a pre-selected direction, and receiving an incoming propagating acoustic wave from the pre-selected direction in the interface of the transparent medium.

In the figures, like reference numerals refer to features and elements having like descriptions, except when indicated otherwise.

DETAILED DESCRIPTION

More than 1 billion speakers in consumer devices, other electronics, public broadcast systems, and other products are sold every year. A transparent speaker would offer many implementation possibilities, in particular in the field of augmented reality (AR) and virtual reality (VR) headsets and smart frame devices, as sufficiently loud speakers may be realized at a light weight with small mass and volume. More generally, embodiments as disclosed herein are directed to transparent acoustic transducers including audio speakers and microphones, ultrasound emitters and sensors, and the like, implemented an optical substrate for use with imaging and vision devices.

In addition, embodiments as disclosed herein include transparent acoustic transducers implemented on optical substrates for use in home windows, car windows, and other indoor or outdoor architectural applications. Architectural and other window applications offer the convenience of having essentially a free form-factor to design an acoustic transducer having the intensity and the accuracy desired for any given application. Moreover, embodiments as disclosed herein include software applications to control transparent transducers as above and provide sensing, detection, ranging, and beaming features to one or more propagating acoustic waves for a desired purpose.

A transparent medium used for an acoustic transducer as disclosed herein may include a membrane or a transparent piezo-electric material. In some embodiments, the membrane includes a transparent organic material, a transparent inorganic material, or any combination of the above. In some embodiments, the transparent organic materials may include a polymer such as Polyvinylidene difluoride (PVDF), ultra-high molecular weight Polyethylene, and the like. Transparent piezo materials are used e.g., in liquid lenses to create variable optical focal powers for AR/VR devices. In some embodiments, the transparent piezo materials may include ceramics such as PMN-PT (tetragonal, electrostrictive, AC poled), Lanthanum nickelate (LNO), Lithium titanate (LTO), in combination with transparent conductive layers such as indium tin oxide, and the like. Other forms of variable lenses are based on transparent membranes driven by edge positioned piezo or electrostatic. In embodiments as disclosed herein, membranes made of transparent piezo material (or other transparent materials) are driven by edge positioned actuators with a frequency range within the human audible spectrum with a variable frequency and amplitude, e.g., between 10 to 140 dB sound pressure level (SPL) to produce sound waves containing information like music, voices, alarms, alerts, and the like. Due to the transparency of membranes and piezoelectric layers as disclosed herein, acoustic transducers as disclosed herein can be implemented in windows, screens of monitors, TVs, cell phones, AR/VR devices, eyeglasses, or other products. It is power efficient due to the piezo or electrostatic movement and can be anti-reflective coated for transparency improvement. In some embodiments, a power circuit provides a voltage amplitude (>50V) to generate acoustic waves of sufficient amplitude to be heard by humans at selected distances.

In embodiments as disclosed herein, a transparent medium includes materials having at least some transmissivity (greater than 0% and up to 100%) for light in the visible spectrum (e.g., from about 400 to about 750 nm), in the infrared spectrum (mostly between 900 nm and 25 um) or any portion of the visible and infrared spectra, or combination thereof.

The transparent medium includes an interface with the environment that oscillates to generate acoustic waves that propagate through the environment (e.g., the atmosphere, air, other gases, liquids, plasmas, or even a solid material). Embodiments as disclosed herein provide the advantage of ubiquitous applications as the transparent medium may be embedded in a window (architectural, indoors/outdoors, vehicle), a screen of a display, or a traffic sign and the like.

In some embodiments, the optical substrate may have a dedicated shape or profile (e.g. the curved surface of a lens, a prism, a reflector, a diffraction grating, and the like) configured to provide an image to the user of the headset, smart frame, or any other optical device. Embodiments as disclosed herein exploit the advantage of implementing rapid acoustic oscillations in the transparent medium (typically much higher than 60 Hz), such that any effect in the deformation of the optical substrate by the oscillations of the transparent medium may be averaged out and undetectable for the user.

FIG.1illustrates a mixed reality device10A including eyeglasses50-1and50-2(hereinafter, collectively referred to as “eyeglasses50”), and transparent speakers100-1and100-2(hereinafter, collectively referred to as “transparent speakers100”), according to some embodiments. A frame1supports eyeglasses50. Mixed reality device10A may include an augmented reality (A/R) device, or a virtual reality (V/R) device having a display115mounted on frame1. Display115may include an optical substrate11configured to provide an image (e.g., through display115or eyeglasses50). In some embodiments, images for display115may be provided by processor circuit20, executing instructions stored in memory circuit12. A power circuit15provides electrical power to an actuator101. In some embodiments, power circuit15is controlled by processor circuit20executing instructions stored in memory circuit12. In some embodiments, power circuit15may include a high voltage optical transformer (HVOT) that is compact and cost efficient to enable more application in the VR/AR space. Actuator101receives the electrical power and provides an electrical excitation or a mechanical excitation to transparent speakers100.

Transducer100includes a transparent medium110coupled to optical substrate11and configured to oscillate based on the frequency and amplitude of the signal received from the processor and the digital signal processing (DSP) unit in response to the electrical excitation or mechanical excitation. In some embodiments, transparent medium110includes a transparent membrane, or a layer of transparent piezoelectric material. In some embodiments, transparent medium110may include an anti-reflective coating for optical transparency improvement at least in a selected portion of the visible spectrum. Acoustic waves produced by the oscillation of transparent medium110may operate in an audible spectral range, e.g., from about 20 Hz to about 20 kHz or in the ultrasonic range (>20 kHz, up to hundreds of kHz, or even one Megahertz, 1 MHz=106Hz). More specifically, in some embodiments, the frequency of acoustic waves generated may be in the range of 1 Hz to 100 kHz. In some embodiments, the amplitude of the acoustic waves is in the range of 10 to 140 dB SPL.

Transparent medium110is moved by actuator101for a displacement, dZ, to create acoustic waves at least partially transmitted through an interface of transparent medium110. In some embodiments, at least a portion of the image is transmitted through transparent medium110. In some embodiments, the displacement dZ is a linear displacement along a direction substantially perpendicular to the interface of transparent medium110(e.g., along the plane of eyeglasses50).

FIG.2illustrates a smart frame10B including two transparent ultrasound emitters200-1and200-2(hereinafter, collectively referred to as “ultrasound emitters200”), according to some embodiments. Memory circuit12, power circuit15, and processor circuit20are as described above in reference to mixed reality device10A. Frame1and eyeglasses50-1and50-2are also as described above, except in this case eyeglasses50may only include an optical substrate11without a display. Accordingly, smart frame device10B may work optically as a regular eyeglass piece for a user40. In some embodiments, processor circuit20may execute instructions to direct power circuit15to provide an electronic excitation or a mechanical excitation via an actuator201, to ultrasound emitters200. Because ultrasound emitters200include a transparent medium (e.g., a membrane or transparent piezoelectric layers), embodiments as disclosed herein can make use of any number of them across the interface of one of the two eyeglasses50, without interfering with the optical performance of smart frame10B.

Ultrasound emitters200generate acoustic waves210-1and210-2(hereinafter, collectively referred to as “acoustic waves210”) which, when they have a pre-determined relative phase, create an ultrasonic beam211that may be scanned over the face of user40. Ultrasonic beam211may be used to perform a depth measurement and obtain a three-dimensional (3D) representation of the face of user40. The choice of the number, position, area, and shape of ultrasound emitters200may be selected to accommodate a desired direction, intensity, and frequency of ultrasonic beam211via instructions in memory circuit12, processor circuit20, and actuator201. In some embodiments, ultrasonic beam211may be used to scan the eye of user40and determine, by retrieving the precise shape of the surface of the eye, a position or direction of the eye pupil.

In some embodiments, ultrasonic beam211may be use more generally in biometrics identification of individuals. Accordingly, every individual have unique 3D geometries of face, eyes, nose (very much like fingerprint), and the relative proportions thereof. Thus, in some embodiments ultrasonic beam211may collect information facial biometric information that can be used to infer if the person who is wearing the device is indeed the owner of the device. Accordingly, if the user is properly identified, the device may be unlocked.

FIGS.3A-3Billustrate television displays30A and30B (hereinafter, collectively referred to as “TV displays30”) including transparent speakers300A,300B-1, and300B-2(hereinafter, collectively referred to as “transparent speakers300”), according to some embodiments. Memory circuit12, power circuit15, and processor circuit20are as described above in reference to mixed reality device10A and smart frame10B. Transparent speakers300include a transparent medium310that induced to oscillate by receiving an electrical excitation or a mechanical excitation from an actuator301, which may be mounted (together with a display315), on a frame1, and powered by a power circuit15. Consistent with the present disclosure, transparent medium300may include a transparent membrane (e.g., including an organic or inorganic material) or a transparent layer of a piezoelectric material.

The induced oscillations of transparent medium300produce propagating acoustic waves through a surface of display315in contact with air. In some embodiments, transparent speakers300B-1and300B-2may be directed to produce propagating acoustic waves having a relative phase adjusted to produce two acoustic beams310-1and310-2(hereinafter, collectively referred to as “acoustic beams310”) directed to each ear of a user45. Accordingly, display30B may provide a stereophonic experience for user45. Consistent with the present disclosure, the relative phase between the acoustic waves produced by transparent speakers300B may be adjusted by processor circuit20upon executing instructions stored in memory circuit12. While display30B includes two transparent speakers300B, this is not limiting of the number, disposition and size of transparent speakers that may be used in TV displays30.

The digital control over acoustic beams310through processors circuit20enables the use of time-sequenced alternating patterns wherein, in a train of pulses provided to transparent speakers300B, some pulses may be directed through beam310-1and other pulses may be directed through beam310-2. The timing pattern may be adjusted at a frequency such that user45perceives acoustic beams310simultaneously, in a “synchronous” experience.

FIGS.4A-4Billustrate eyeglasses450A and450B (hereinafter, collectively referred to as “eyeglasses450”) including actuators401A and401B (hereinafter, collectively referred to as “actuators401”) for providing an electrical excitation or a mechanical excitation to transparent substrates400A and400B (hereinafter, collectively referred to as “transparent substrates400”) in eyeglasses450, according to some embodiments. Substrate400A may include a transparent membrane and substrate400B may include a transparent piezoelectric layer.

Substrates400are moved through actuators401. In some embodiments, actuators401are edge-positioned actuators that produce a displacement, dZ, substantially perpendicular to an interface of substrate400A with the medium in which eyeglasses450are embedded. The oscillatory displacement of substrates400creates an acoustic wave that propagates through the medium. The medium through which the acoustic wave propagates may be air, any other gas, a liquid, or any other fluid.

FIG.5illustrates different oscillation modes531A,531B, and531C (hereinafter, collectively referred to as “oscillation modes531”) of a transparent substrate500in an eyeglass550, according to some embodiments. A Cartesian reference frame XYZ is illustrated to facilitate the understanding of the disclosure, but is not intended to be limiting in any aspect as to the orientation, arrangement, and configuration of the disclosed features. Accordingly, without limitation and for illustrative purposes only, transparent substrate500may be assumed to lay in the XY-plane of the Cartesian reference frame.

Oscillation modes531may be selected by configuring the excitation provided to transparent substrate500by an actuator501. Each of oscillation modes531can have a different frequency response and a different loudness curve that may be exploited to the advantage of the user by electronically adjusting the electrical power provided to actuator501. For example, in some embodiments, the frequency, phase, and direction of one or more electrical signals to actuator501may be controlled via software instructions stored in a memory circuit and executed by a processor circuit as disclosed herein.

In some embodiments, modes531A and531B may result from displacements induced in transparent substrate500(e.g., a piezoelectric layer) perpendicularly (along the X-axis or Y-axis, respectively) to an electric field, E, applied by actuator501(e.g., E along the Z-axis). In mode531C, the direction of the oscillation of the piezoelectric layer may be parallel to the electric field (e.g., along the Z-axis).

FIG.6illustrates transparent speakers600A-1and600A-2(hereinafter, collectively referred to as “transparent speakers600A”) in a store window615inside a mall65, according to some embodiments. In some embodiments, store window615may also include transparent ultrasonic transducers600B-1and600B-2(hereinafter, collectively referred to as “ultrasonic transducers600B”). Memory circuit12stores instructions to be executed by processor circuit20to cause transparent speakers600A to operate as disclosed herein. In addition, power circuit15provides the electrical power to memory circuit12, processor circuit20, and transparent speakers600A.

Two shoppers60A and60B (hereinafter, collectively referred to as “shoppers60”), move outside of the store, in different directions relative to store window615. The displacement (e.g., direction, distance, and speed) of shoppers60may be detected by transparent ultrasonic transducers600B. Based on the displacement of shoppers60, transparent speakers600A may be configured by software instructions executed by processor circuit20to direct an acoustic beam610-1to shopper60A and an acoustic beam610-2to shopper60B. In some embodiments, and given the different compulsion of shoppers60, acoustic beams610may be directed in different directions, and also include a different sound message to shoppers60A and60B. For example, on noticing that shopper60B is headed for the mall exit, acoustic beam610-2may include a farewell and thank you message. And noticing that shopper60A is headed towards shopping window615, acoustic beam610-1may include an enticing message.

FIGS.7A-7Billustrate transparent speakers700A-1and700A-2, (hereinafter, collectively referred to as “transparent speakers700A”), and transparent ultrasonic transducers700B-1,700B-2,700B-3,700B-4,700B-5,700B-6,700B-7,700B-8,700B-9,700B-10,700B-11, and700B-12(hereinafter, collectively referred to as “transparent ultrasonic transducers700B”) in car windows, according to some embodiments. Memory circuit12stores instructions to be executed by processor circuit20to cause transparent speakers700A and transparent ultrasonic transducers700B to operate as disclosed herein. In addition, power circuit15provides the electrical power to memory circuit12, processor circuit20, transparent speakers700A, and transparent ultrasonic transducers700B.

The ability of adding a transparent substrate as disclosed herein within the large area of car windows provides an opportunity to use the technology disclosed herein for handling audio signals to the occupants of a car75A at a desired volume and with added stereophonic features. Also, the use of transparent substrates as disclosed herein in car windows may further expand the use of ultrasound sensors for accurately determining the relative positions of cars75B-1,75B-2, and75B-3, in traffic or stationary.

FIG.7Aillustrates a driver70of a car75A wherein a windshield715includes transparent speakers700A. In some embodiments, two transparent speakers700A are combined to generate acoustic beams710-1and710-2(hereinafter, collectively referred to as “acoustic beams710”), directed to each ear of driver70. Accordingly, transparent speakers700A may provide a stereophonic audio signal to driver70. In addition, transparent ultrasonic transducers700B-1and700B-2may be configured to scan the face and the eyes of driver70, and determine an acuity and attention of the driver on the road ahead. For example, in some embodiments, upon determining that driver70is getting drowsy, falling asleep, or simply not paying attention to the road ahead, processor circuit20may direct transparent speakers700A to provide a loud alert to driver70.

FIG.7Billustrates cars75B-1,75B-2, and75B-3(hereinafter, collectively referred to as “cars75B”) equipped with transparent ultrasonic transducers700B in one or more windows, as disclosed herein. Using transparent ultrasonic transducers700B, cars75B may accurately and quickly determine the relative positions720A,720B, and720C (hereinafter, collectively referred to as “relative positions720”) between the cars. The use of transparent substrates as disclosed herein enables the implementation of multiple, large area ultrasonic sensors that may have a longer reach and more accuracy to pinpoint relative positions720. In some embodiments, cars75B may also include transparent speakers inside the car (e.g., transparent speakers700A), which may be instructed by processor circuit20to alert the driver of any dangerous proximity of another car, a pedestrian, or any other obstacle in the road.

FIG.8is a flowchart illustrating steps in a method800for generating a propagating acoustic wave using a transparent substrate in a display, window, or lens, according to some embodiments. Method800may be performed, at least partially, by a processor circuit executing instructions stored in a memory circuit in a mixed reality device, a smart frame, a display, a window, or a lens, as disclosed herein (cf. memory circuit12and processor circuit20, mixed reality device10A, smart frame device10B, TV display30A, eyeglasses450, store window615, and windshields715). The devices may include an optical substrate and a transparent medium forming a transparent transducer, configured to provide or receive a propagating acoustic wave or an acoustic beam at a pre-determined frequency and in a pre-selected direction (e.g., transparent speakers100,300,400,600,700A, and transparent ultrasonic transducers200,700B). Embodiments consistent with the present disclosure may include methods having at least one or more of the steps in method800performed in a different order, simultaneously, quasi-simultaneously, or overlapping in time.

Step802includes filtering an electrical power to an electrode coupled to a transparent medium in a speaker to select the pre-determined frequency for an electrical excitation or a mechanical excitation of the transparent medium.

Step804includes providing the electrical excitation or the mechanical excitation to generate a propagating acoustic wave from an interface in the transparent medium at the pre-determined frequency.

Step806includes directing the propagating acoustic wave in the pre-selected direction. In some embodiments, step806includes scanning a surface of a nearby object to identify a distance, a shape, or a consistency of the nearby object. In some embodiments, step806includes combining a first acoustic wave from the transparent medium and a second acoustic wave from the transparent medium, the first acoustic wave and the second acoustic wave having the pre-determined frequency and separated by a phase selected based on a source point of the first acoustic wave, a source point of the second acoustic wave, and the pre-selected direction.

Step808includes receiving an incoming propagating acoustic wave from the pre-selected direction in the interface of the transparent medium. In some embodiments, step808includes generating a warning when the incoming propagating acoustic wave is indicative of a nearby object that has moved into an unsafe position.

Hardware Overview

FIG.9is a block diagram illustrating an exemplary computer system900with which the devices ofFIGS.1-6(e.g., mixed reality devices, smart frames10A,10B, TV displays30, store window600and car windows), and the method ofFIG.8can be implemented. In certain aspects, the computer system900may be implemented using hardware or a combination of software and hardware, either in a dedicated server, or integrated into another entity, or distributed across multiple entities.

Computer system900includes a bus908or other communication mechanism for communicating information, and a processor902(e.g., processor circuit20) coupled with bus908for processing information. By way of example, the computer system900may be implemented with one or more processors902. Processor902may be a general-purpose microprocessor, a microcontroller, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Programmable Logic Device (PLD), a controller, a state machine, gated logic, discrete hardware components, or any other suitable entity that can perform calculations or other manipulations of information.

Computer system900can include, in addition to hardware, a code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them stored in an included memory904(e.g., memory circuit12), such as a Random Access Memory (RAM), a flash memory, a Read-Only Memory (ROM), a Programmable Read-Only Memory (PROM), an Erasable PROM (EPROM), registers, a hard disk, a removable disk, a CD-ROM, a DVD, or any other suitable storage device, coupled to bus908for storing information and instructions to be executed by processor902. The processor902and the memory904can be supplemented by, or incorporated in, a special purpose logic circuitry.

Computer system900further includes a data storage device906such as a magnetic disk or optical disk, coupled to bus908for storing information and instructions. Computer system900may be coupled via input/output module910to various devices. Input/output module910can be any input/output module. Exemplary input/output modules910include data ports such as USB ports. The input/output module910is configured to connect to a communications module912. Exemplary communication modules912include networking interface cards, such as Ethernet cards and modems. In certain aspects, input/output module910is configured to connect to a plurality of devices, such as an input device914and/or an output device916. Exemplary input devices914include a keyboard and a pointing device, e.g., a mouse or a trackball, by which a user can provide input to the computer system900. Other kinds of input devices914can be used to provide for interaction with a user as well, such as a tactile input device, visual input device, audio input device, or brain-computer interface device. For example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback, and input from the user can be received in any form, including acoustic, speech, tactile, or brain wave input. Exemplary output devices916include display devices, such as an LCD (liquid crystal display) monitor, for displaying information to the user.

According to one aspect of the present disclosure, mixed reality device10A can be implemented using a computer system900in response to processor902executing one or more sequences of one or more instructions contained in memory904. Such instructions may be read into memory904from another machine-readable medium, such as data storage device906. Execution of the sequences of instructions contained in main memory904causes processor902to perform the process steps described herein. One or more processors in a multi-processing arrangement may also be employed to execute the sequences of instructions contained in memory904. In alternative aspects, hard-wired circuitry may be used in place of or in combination with software instructions to implement various aspects of the present disclosure. Thus, aspects of the present disclosure are not limited to any specific combination of hardware circuitry and software.