Abstract: Various techniques for driving phased array systems are described, specifically intended for acoustic phased arrays with applications to mid-air haptics, parametric audio, acoustic levitation and acoustic imaging, including a system: 1) that is capable of mitigating the effect of the changes in the air to provide a consistent haptic experience; 2) that produces trap points in air; 3) that defines phased-array optimization in terms of vectors for the production of more consistent haptic effects; 4) that defines one or more control points or regions in space via a controlled acoustic field; 5) that uses a reduced representation method for the construction of acoustic basis functions; 6) that performs efficient evaluation of complex-valued functions for a large quantity of throughput; 7) that generates a Krylov sub-space of a matrix; and 8) that maximizes an objective described by different control points and/or regions to those used to create the acoustic basis functions.

Abstract: To resolve an issue related to the calibration of optical cameras in transducer-based mid-air haptic systems, the magnification of the motion induced on an optical camera by an acoustic field modulated at specific frequencies reveals very small temporal variations in video frames. This quantized distortion is used to compare different acoustic fields and to solve the calibration problem in an automatized manner. Further, mechanical resonators may be excited by ultrasound when it is modulated at the resonant frequency. When enough energy is transferred and when operating at the correct frequency, a user in contact with the device can feel vibration near areas of largest displacement. This effect can be exploited to create devices which can produce haptic feedback while not carrying a battery or exciter when in the presence of an ultrasonic source.

Abstract: The present invention concerns a method and apparatus for the modulation of an acoustic field for providing tactile sensations. A method of creating haptic feedback using ultrasound is provided. The method comprises the steps of generating a plurality of ultrasound waves with a common focal point using a phased array of ultrasound transducers, the common focal point being a haptic feedback point, and modulating the generation of the ultrasound waves using a waveform selected to produce little or no audible sound at the haptic feedback point.

Abstract: A system providing various improved perceptions techniques for haptic feedback above interactive surfaces that require no contact with either tools, attachments or the surface itself is described. A range of receptors in a perceiving member which is part of the human body is identified to create substantially uniformly perceivable feedback. A vibration frequency that is in the range of the receptors in the perceiving member is chosen and dynamically altered to create substantially uniformly perceivable feedback throughout the receiving member.

Abstract: The present disclosure concerns a method and apparatus for the creation of an acoustic field for providing tactile sensations. More particularly, but not exclusively, this disclosure concerns a method and apparatus for the creation of an acoustic field providing tactile sensations for use with an interactive device. The disclosure provides a method of generating a tactile sensation. The method comprises the steps of providing a plurality of acoustic transducers arranged to generate a predetermined distribution of pressure patterns, wherein the pressure patterns comprise a first region providing a first tactile sensation and a second region providing a second, different, tactile sensation.

Abstract: An acoustic field may be produced from a transducer array having known relative positions and orientations In this acoustic field, one or more control points may be defined. An amplitude may be assigned to the control point. Mid-air haptic effect for a virtual object on a human body part may be generated by moving the control point in a single closed curve comprising a plurality of curve segments. The single closed curve traverses at least one location where the human body part intersects with the virtual object. Additionally, a user may interact with virtual three-dimensional content using the user's hands while a tracking system monitoring the user's hands, a physics engine updates the properties of the virtual three-dimensional content and a haptic feedback system provides haptic information to the user.

Abstract: A system providing various improved calibration techniques for haptic feedback is described. An acoustic field is defined by one or more control points in a space within which the acoustic field may exist. Each control point is assigned an amplitude value equating to a desired amplitude of the acoustic field at the control point. Because complete control of space is not possible, controlling the acoustic field at given points yields erroneous local maxima in the acoustic field levels at other related positions. In relation to mid-air haptic feedback, these can interfere in interactions with the space by creating secondary effects and ghost phenomena that can be felt outside the interaction area. The level and nature of the secondary maxima in the acoustic field is determined by how the space is controlled. By arranging the transducer elements in different ways, unwanted effects on the acoustic field can be limited and controlled.

Abstract: Described is a screen surface layer comprising a plurality of light-emitting pixels including a plurality of red pixels, a plurality of green pixels and a plurality of blue pixels; a transducer layer comprising a plurality of acoustic transducers, wherein the transducer layer is affixed below the screen surface layer; and a cover layer having a plurality of cylinder-shaped perforations, wherein the cover layer is affixed above the screen surface layer. In addition, an average “transducer model” describing a phasor distribution in space may be produced describing the output signal at the carrier frequency in the air at a known spatial offset from an averaged transducer. Further, phased array systems may have numerous individual transducer elements that will likely fail before the product incorporating the transducers reaches end-of-life. By detecting such failed transducers, the transducer array may function at peak performance by working around the missing transducer output.

Abstract: An acoustic field may be produced from a transducer array having known relative positions and orientations in this acoustic field, one or more control points may be defined. An amplitude may be assigned to the control point. Mid-air haptic effect for a virtual object on a human body part may be generated by moving the control point in a single closed curve comprising a plurality of curve segments. The single closed curve traverses at least one location where the human body part intersects with the virtual object. Additionally, a user may interact with virtual three-dimensional content using the user's hands while a tracking system monitoring the user's hands, a physics engine updates the properties of the virtual three-dimensional content and a haptic feedback system provides haptic information to the user.

Abstract: A circuit for driving a transducer in a mid-air haptic system includes a voltage source, a voltage sink, a current source, a trickle capacitor, a storage capacitor, a haptic system transducer, a first switch, a second switch, and a third switch. Using these components, a portion of the charge required for switching a transducer is sourced from the decoupling capacitance. When the switching completes, additional charge is transferred immediately from the power supply back into the decoupling capacitance. This acts to lower the peak current by fully utilizing 100% of a switching waveform for transfer of charge from the power supply to capacitors local to the transducer.

Abstract: The present invention concerns a method and apparatus for the modulation of an acoustic field for providing tactile sensations. A method of creating haptic feedback using ultrasound is provided. The method comprises the steps of generating a plurality of ultrasound waves with a common focal point using a phased array of ultrasound transducers, the common focal point being a haptic feedback point, and modulating the generation of the ultrasound waves using a waveform selected to produce little or no audible sound at the haptic feedback point.

Abstract: An acoustic field may be produced from a transducer array having known relative positions and orientations In this acoustic field, one or more control points may be defined. An amplitude may be assigned to the control point. Mid-air haptic effect for a virtual object on a human body part may be generated by moving the control point in a single closed curve comprising a plurality of curve segments. The single closed curve traverses at least one location where the human body part intersects with the virtual object. Additionally, a user may interact with virtual three-dimensional content using the user's hands while a tracking system monitoring the user's hands, a physics engine updates the properties of the virtual three-dimensional content and a haptic feedback system provides haptic information to the user.

Abstract: A system providing various improved perceptions techniques for haptic feedback above interactive surfaces that require no contact with either tools, attachments or the surface itself is described. A range of receptors in a perceiving member which is part of the human body is identified to create substantially uniformly perceivable feedback. A vibration frequency that is in the range of the receptors in the perceiving member is chosen and dynamically altered to create substantially uniformly perceivable feedback throughout the receiving member.

Abstract: A system providing various improved processing techniques for haptic feedback is described. An acoustic field is defined by one or more control points in a space within which the acoustic field may exist. Each control point is assigned an amplitude value equating to a desired amplitude of the acoustic field at the control point. Transducers are then controlled to create an acoustic field exhibiting the desired amplitude at each of the control points. When human skin interacts with the acoustic field, vibrations of the skin are interpreted by mechanoreceptors being excited and sending signals to the brain via the nervous system. Improved processing techniques allow for more efficient real-world operation.

Abstract: A plurality of control points are defined having a known spatial relationship relative to an array of transducers. An amplitude is assigned to each control point. A matrix is produced containing elements which represent, for each of the control points, the effect that producing a modeled acoustic field having the assigned amplitude with a particular phase at the control point has on the consequential amplitude and phase of the modeled acoustic field at the other control points. Eigenvectors of the matrix are determined, each eigenvector representing a set of phases and relative amplitudes of the modeled acoustic field at the control points. One of the sets is selected and the transducer array is operated to cause one or more of the transducers to output an acoustic wave each having an initial amplitude and phase such that the phases and amplitudes of the resultant acoustic field at the control points correspond to the phases and relative amplitudes of the selected set.

Abstract: The present invention concerns a method and apparatus for the modulation of an acoustic field for providing tactile sensations. A method of creating haptic feedback using ultrasound is provided. The method comprises the steps of generating a plurality of ultrasound waves with a common focal point using a phased array of ultrasound transducers, the common focal point being a haptic feedback point, and modulating the generation of the ultrasound waves using a waveform selected to produce little or no audible sound at the haptic feedback point.

Abstract: The present disclosure concerns a method and apparatus for the creation of an acoustic field for providing tactile sensations. More particularly, but not exclusively, this disclosure concerns a method and apparatus for the creation of an acoustic field providing tactile sensations for use with an interactive device. The disclosure provides a method of generating a tactile sensation. The method comprises the steps of providing a plurality of acoustic transducers arranged to generate a predetermined distribution of pressure patterns, wherein the pressure patterns comprise a first region providing a first tactile sensation and a second region providing a second, different, tactile sensation.

Abstract: The present disclosure concerns a method and apparatus for the creation of an acoustic field for providing tactile sensations. More particularly, but not exclusively, this disclosure concerns a method and apparatus for the creation of an acoustic field providing tactile sensations for use with an interactive device. The disclosure provides a method of generating a tactile sensation. The method comprises the steps of providing a plurality of acoustic transducers arranged to generate a predetermined distribution of pressure patterns, wherein the pressure patterns comprise a first region providing a first tactile sensation and a second region providing a second, different, tactile sensation.