REVIEWS OF ACOUSTICAL PATENTS

• GEORGE L. AUGSPURGER, Perception, Incorporated, Box 39536, Los Angeles, California 90039

• JOHN A. HOSSACK, Department of Biomedical, Electrical and Computer Engineering, University of Virginia, Charlottesville, Virginia 22908

• BENJAMIN MARKHAM, Acentech Incorporated, 33 Moulton Street, Cambridge, Massachusetts 02138

Afrooz Family et al., assignors to Apple Inc.

16 October 2018; filed 27 April 2017

Modern digital processing enables an array of loudspeakers to create simultaneous beams of sound aimed in various directions. Using this technology, a pair of small smart-speakers can reproduce five or more channels of surround sound, with some channels directed toward the listener and other channels reflected from room surfaces. However, if a loudspeaker is shifted, or if the listening area is moved, the electronic processing must be reconfigured. This patent suggests that the process can be largely automated, using a computer or smartphone to generate test signals and analyze the results. Audio tests are augmented by video analysis, as noted in step 605 of the flow chart. The procedure seems clear enough, except that the patent Claims mysteriously require two sets of speaker arrays.—GLA

Paul Yaffe

30 October 2018; filed 31 May 2017

The invention described here is a convertible motorcycle saddlebag. The lid is designed to accommodate an optional loudspeaker, allowing the saddlebag to be used with or without a sound system. There is no mention of weather protection for the loudspeaker, and no explanation of how the lid would be configured with no loudspeaker installed.—GLA

Feng-Ming Liu et al., assignors to ACER INCORPORATED

16 October 2018; filed 29 August 2016

The invention disclosed in this patent is a shallow triple-chamber loudspeaker enclosure intended for use in tablet computers. The illustration is a top view with the cover removed. Upward-facing loudspeaker 21 has a sealed rear chamber. The front of the speaker drives chamber 201, which communicates with chamber 221 through duct 230. Sound exits from opening 220. It might be described as a single-ended, double-tuned bandpass enclosure, but there are enough variables to create a wide variety of response curves.—GLA

Heinz Epping et al., assignors to Sennheiser electronic GmbH & Co. KG

23 October 2018; filed 8 December 2016

When recording an amplified guitar, a microphone (or a microphone pair) is located close to the guitar speaker. In this near-field situation, a slight change in microphone position can produce a substantial change in tonal quality, and finding the optimum microphone position for a given guitar speaker can be a lengthy procedure. This patent describes a microphone mounting frame that can easily be aligned to almost any guitar speaker cabinet. The microphone position is then adjusted within the frame and locked in place, enabling a quick setup in subsequent recording sessions.—GLA

Patrik Boström et al., assignors to BOLECANO HOLDING AB

2 October 2018; filed 20 May 2016

This patent begins with a well-written explanation of various topologies used in Class D audio power amplifiers, with emphasis on self-oscillating designs. A new variation is then disclosed that is said to provide lower distortion and more stable operation. Input amplifier 102 acts as an integrating regulator for power amplifier 100, with the input signal as a reference signal and the feedback signal as a present value signal.—GLA

Mark Robert Every et al., assignors to 2236008 Ontario, Inc.

23 October 2018; filed 17 February 2017

This patent addresses the challenge of amplifying sound from anywhere to everywhere in an enclosed space. Most prior art deals with boardroom amplification, but in this case the enclosed space is a motor vehicle. Multiple microphones and loudspeakers are controlled by fairly elaborate electronic processing. The processing includes echo cancellation but the focus of the patent lies in establishing forward path frequency-dependent gains and then adjusting the actual gains to avoid triggering acoustic feedback.—GLA

Frank C. Valeri et al., assignors to GM GLOBAL TECHNOLOGY OPERATIONS LLC

2 October 2018; filed 29 March 2017

A classic high-performance automobile generates distinctive grunts and whines during rapid acceleration, but modern vehicles have quiet cabins in which engine noise and road noise are suppressed. This patent suggests that such a vehicle's audio system can be used to introduce appropriate sounds when acceleration exceeds a certain value.—GLA

William G. Crutchfield, Jr. and Richard I. Wright, assignors to Crutchfield Corporation

2 October 2018; filed 19 April 2017

This patent contains more speculation than invention. The goal is to create an active reference environment that can simulate the performance of various loudspeakers in various spaces under various conditions. For example, a prospective customer for an auto sound system could hear what it would sound like in a particular BMW model at 65 mph with the windows closed. The patent points out that a realistic simulation involves a lot more than simply equalizing the response of speaker B to match the on-axis response of speaker A, but an actual method for achieving the desired three-dimensional sound field is pretty much left up in the air. —GLA

Michael Arnold et al., assignors to Thomson Licensing

16 October 2018; filed 15 December 2016

This patent describes yet another smartphone app. The goal is to accurately determine the azimuth and elevation of individual loudspeakers in a surround sound installation, referenced to a given listening location. Well, yes—if the phone has at least two microphones, and if the microphones are identical (or individually calibrated), and if the smartphone can be accurately positioned, and if there are no strong room reflections then the phase difference can be used to calculate the angle. In some circumstances, where direct measurement or optical sighting is difficult, such a method might be useful.—GLA

Christian Borss et al., assignors to Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.

9 October 2018; filed 14 July 2017

In many residential surround sound installations, some loudspeakers cannot be placed at the recommended locations. What is the best way to reproduce surround sound in such a situation? Numerous patents propose various methods, and this patent adds another method to the list. First, using an energy distribution matrix, an imaginary speaker is created at a specified location not matched by any of the real speakers. The imaginary speaker is employed as a locator to create an entire imaginary speaker setup. The imaginary speaker setup is then downmixed according to the energy distribution such that the real setup can be controlled as if it were the imaginary setup.—GLA

David E. Heverly, II et al., assignors to Bell Helicopter Textron Inc.

30 October 2018; filed 23 September 2014

According to this patent, helicopter rotor assemblies typically include passive dampers. “The function of a rotor damper is to reduce the inplane (lead-lag) motions of the rotor blade and also reduce the oscillatory forces transmitted from the blades to the rotor hub.” An improved active damping system is described that includes displacement sensors in a closed loop feedback system.—GLA

Masahiro Ishida and Naoki Matsuda, assignors to Ricoh Company, Ltd.

2 October 2018; filed 20 May 2016

For use in a photocopier, this patent is for an image-forming device that incorporates noise control via cavity absorption. The cavities are built into an electrophotographic image-forming apparatus.—BEM

Shinya Hakuta et al., assignors to FUJIFILM Corporation

16 October 2018; filed 17 August 2017

A thin film/panel described here is intended to block sound in the stiffness-controlled region below 500 Hz. The film comprises a stiff structure containing individual cells; the cells, in turn, comprise a film affixed to a frame with through-holes in the frame and holes drilled into the film, all arranged to insulate a pre-determined frequency band.—BEM

Silvia Maria Booij and Ronald Cornelis De Gier, assignors to PHILIPS LIGHTING HOLDING B.V.

2 October 2018; filed 20 May 2014

Many spaces require both uniform lighting and broad sound absorption, often on the ceiling. This invention provides both: a sandwich panel that contains a light source, light-emitting surfaces arranged in parallel with sound-absorbing surfaces, and a bottom layer (facing the room) that transmits diffuse light and also allows for the transmission of sound into the sound-absorbing layers behind. The patent also provides for holes cut through the panel for sensors, ventilation, sprinklers, or other auxiliary functions.—BEM

David D. Larson et al., assignors to PROGRESS PROFILES SPA

23 October 2018; filed 12 July 2017

This patent pertains to underfloor heating elements. The focus of the patent does not pertain to acoustics, but underlayments for in-floor radiant heat can also incorporate a sound damping pad to reduce the transmission of footfall noise in the floor structure—a possibility anticipated by this patent.—BEM

George K. Lewis, Jr. et al., assignors to CORNELL UNIVERSITY

9 October 2018; filed 13 April 2012

This patent relates to the use of a divergent beam ultrasound transducer system with the object of more reliably being able to detect evidence of fetal distress during the course of a high-risk delivery. A divergent beam is used to facilitate higher probability of being able to detect fetal blood flow via Doppler processing.—JH

Jonathan Michael Byars and Garrett Leigh Wong, assignors to Kulicke and Soffa Industries, Inc.

9 October 2018; filed 15 February 2018

This patent describes a method for aligning tooling for an ultrasonic bonding system typically used in integrated circuit (IC) fabrication for the purpose of connecting from IC pads to external leads. The method involves providing an image overlay showing the relative position of the tooling element(s) with respect to the intended bond targets for the purpose of facilitating proper alignment. In this particular invention, the bonding system has “clamp fingers” that need to be aligned.—JH

Elisa E. Konofagou and Hermes Arytto Salles Kamimura, assignors to THE TRUSTEES OF COLUMBIA UNIVERSITY IN THE CITY OF NEW YORK

16 October 2018; filed 10 February 2016

This patent involves a method for non-invasive brain stimulation comprising: securing an ultrasound transducer in a fixed position relative to the patient's brain; providing focused ultrasound to a selected location in the brain with the intent of evoking a physical response in the patient; and measuring the response of the patient by using at least one of: a body movement, an eye movement, or pupil dilation. Ultrasound in the range 1–5 MHz is employed with focal depths in the range 2 to 20 mm.—JH

Lihong Wang et al., assignors to Washington University

23 October 2018; filed 28 April 2016

The invention describes a photoacoustic endoscope comprising: a catheter tube; a laser light source suitable for photoacoustic imaging; an ultrasonic transducer configured to detect a photoacoustic response signal that is in a fixed location within the catheter tube; and a rotatable light and acoustic reflector that is employed within the catheter to effect circumferential scanning to form cross-sectional images perpendicular to the axis of the catheter.—JH