Virtual, augmented, or mixed reality device
A portable virtual, augmented, or mixed reality device, including: a mount intended to be worn on a user's head; a display screen attached to the mount and intended to be arranged in front of one of the user's eyes; a plurality of ultrasound transducers attached to the mount; and a control circuit configured to control the display screen to display images, and the ultrasound transducers to generate, in air, at a distance from the mount, a pressure distribution detectable by the user's hand to obtain a haptic effect.
1. A portable virtual, augmented, or mixed reality device, comprising:
a mount configured to be worn on a head of a user;
a display screen attached to the mount and configured to be arranged in front of an eye of the user;
a plurality of ultrasound transducers attached to the mount;
a detection system configured to use one or more of the ultrasound transducers to emit ultrasound waves to an environment in front of the user when the mount is worn by the user, to detect a location of a hand of the user in the environment in front of the user; and
a control circuit configured to control the display screen to display images, and to control at least one of the ultrasound transducers to generate, in air, at the location of the hand detected by the detection system, a haptic effect via a pressure distribution detectable by the hand at the location of the hand detected by the detection system,
wherein the detection system detects the location of the hand of the user in a first phase, and the control circuit generates the haptic effect in a second phase after the location of the hand has been detected by the detection system.
2. The device of claim 1 , wherein the control circuit is configured to read output data of the detection system and accordingly modify the control of the display screen and the control of the ultrasound transducers.
3. The device of claim 1 , wherein the ultrasound transducers are piezoelectric transducers.
4. The device of claim 3 , wherein each of the ultrasound transducers comprises:
a flexible membrane suspended on a rigid support, and
a piezoelectric conversion element bonded to the flexible membrane.
5. The device of claim 1 , wherein each of the ultrasound transducers is arranged in a cavity formed in the mount.
6. The device of claim 1 , further comprising, between the ultrasound transducers and a face of the user when the mount is worn by the user, an element made of a material for absorbing the ultrasound waves emitted by the ultrasound transducers.
7. The device of claim 1 , wherein the control circuit is configured to control an emission of ultrasound pulses by the ultrasound transducers with phase shifts between different selected ones of the ultrasound transducers to focus waves of the emitted ultrasound pulses on a selected point in space.
8. The device of claim 1 , wherein the one or more ultrasound transducers used by the detection system to detect the location of the hand of the user are different from the at last one of the ultrasound transducers controlled by the control circuit to generate the haptic effect.
9. The device of claim 8 , wherein the one or more ultrasound transducers used by the detection system operate simultaneously with the at last one of the ultrasound transducers controlled by the control circuit to generate the haptic effect.
10. The device of claim 1 , wherein the one or more ultrasound transducers used by the detection system to detect the location of the hand of the user are same as the at last one of the ultrasound transducers controlled by the control circuit to generate the haptic effect.
11. The device of claim 10 , wherein the one or more ultrasound transducers used by the detection system operate sequentially with the at last one of the ultrasound transducers controlled by the control circuit to generate the haptic effect.