Haptic effects from focused acoustic fields

Patent metadata

Field	Value
Publication number	US-11921928-B2
Application number	US-202218066267-A
Country	US
Kind code	B2
Filing date	Dec 14, 2022
Priority date	Nov 26, 2017
Publication date	Mar 5, 2024
Grant date	Mar 5, 2024

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.

First claim

The invention claimed is:

1. A method comprising:
scanning a focused acoustic field through space from an acoustic source until the focused acoustic field impinges upon an element of a camera with sufficient amplitude to cause vibration of the camera to a detectable level; and
estimating a relative location of the camera to the acoustic source based on the vibration of the camera.

2. The method as in claim 1 , further comprising:
detecting a camera imager blur via a contrast detection algorithm.

3. The method as in claim 2 , wherein the contrast detection algorithm compares a standard camera image contrast with a vibrating camera image contrast.

4. The method as in claim 3 , wherein the contrast detection algorithm further comprises excluding regions with possible changes.

5. The method as in claim 3 , further comprising:
determining a focus produced by the acoustic source that maximizes camera displacement.

6. The method as in claim 3 , wherein the contrast detection algorithm further comprises spatial and temporal processing to amplify the camera imager blur.

7. The method as in claim 2 , wherein the focused acoustic field includes a modulated carrier wave.

8. The method as in claim 7 , wherein the modulated carrier wave is calibrated to obtain a desired frequency of camera vibration.

9. The method as in claim 1 , further comprising:
detecting camera motion via a motion magnification algorithm.

10. The method as in claim 9 , further comprising:
detecting a camera imager blur via a contrast detection algorithm.

11. The method as in claim 10 , wherein the contrast detection algorithm compares a standard camera image contrast with a vibrating camera image contrast.

12. The method as in claim 11 , wherein the contrast detection algorithm further comprises excluding regions with possible changes.

13. The method as in claim 11 , further comprising:
determining a focus produced by e acoustic source that maximizes camera displacement.

14. The method as in claim 11 , wherein the contrast detection algorithm further comprises spatial and temporal processing to amplify the camera imager blur.

15. The method as in claim 10 , wherein the focused acoustic field includes a modulated carrier wave.

16. The method as in claim 15 , wherein the modulated carrier wave is calibrated to obtain a desired frequency of camera vibration.

Assignees

• Ultrahaptics Ip Ltd

Inventors

• Iodice Michele
• Kappus Brian
• Long Benjamin John Oliver

Classifications

• G06F3/016 Primary

  Input arrangements with force or tactile feedback as computer generated output to the user · CPC title

• G06F3/017

  Gesture based interaction, e.g. based on a set of recognized hand gestures (interaction based on gestures traced on a digitiser G06F3/04883) · CPC title

• G06F3/0304

  Detection arrangements using opto-electronic means (constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042) · CPC title

• G06F3/03545

  Pens or stylus · CPC title

• G06F3/038

  Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry · CPC title