Touch-sensitive device

• US 20100302184A1
• Filed: 12/09/2008
• Published: 12/02/2010
• Est. Priority Date: 12/11/2007
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: New Transducers Limited (Alphabet Inc.)
• Inventors: Boyd, Geoffrey A., Cowdery, Chris, Whitwell, Timothy Christopher Johnson, East, James, Harris, Neil, Colloms, Martin
• Granted Patent: US 8,736,558 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user
• CPC Class Codes: G06F 3/0433 in which the acoustic waves are either generated by a movable member and propagated within a surface layer or propagated within a surface layer and captured by a movable member
• CPC Class Codes: H04R 7/045 using the distributed mode principle, i.e. whereby the acoustic radiation is emanated from uniformly distributed free bending wave vibration induced in a stiff panel and not from pistonic motion

Abstract

A user/machine interface comprising a panel having a surface, the panel being capable of supporting bending waves, a touch-sensitive input device associated with the surface, and means including a force transducer for providing force feedback to the input device. The force is in the form of pulses to the panel, the pulses being in the form of a modulated signal shaped as a damped sinusoid whereby a button click sensation is provided to the user'"'"'s finger tip. The modulated signal may be produced by a narrow-band sine wave having a carrier frequency in the range 150 to 750 Hz and being of a duration of at least 10 ms.

Claims

1. A user/machine interface comprising a panel having a surface, the panel being capable of supporting bending waves, a touch-sensitive input device associated with the surface, means including a force transducer for providing force feedback to the input device, the force being in the form of pulses to the panel, the pulses being in the form of a modulated signal whereby a button click sensation is provided to the user'"'"'s finger tip, where the modulated signal has a dominant carrier frequency in the range 150 to 750 Hz and being of a duration of at least 10 ms.

2. A user/machine interface according to claim 1, wherein the carrier frequency is at or close to 400 Hz.

3. A user/machine interface according to claim 1 or claim 2, wherein the pulse duration is no more than 40 ms.

4. A user/machine interface according to claim 1, wherein the modulated signal is amplitude modulated.

5. A user/machine interface according to claim 4, wherein the amplitude modulated signal is in the form of a damped sinusoid.

6. A machine/user interface according to claim 1, wherein the modulated signal is frequency modulated.

7. A machine/user interface according to claim 6, where the frequency modulation of the carrier has a predetermined function defining modulation depth and content with time.

8. A machine/user interface according to claim 1, wherein the modulated signal fundamental comprises a narrow-band sine wave.

9. Apparatus comprising a user/machine interface as claimed in claim 1, wherein the panel is the acoustic radiator of a bending wave panel loudspeaker, and wherein the transducer is a broad-band device that generates both acoustic output and force feedback.

10. Apparatus according to claim 9, wherein the transducer comprises a distributed mode actuator and wherein the first mode of the distributed mode actuator is tuned to the modulated signal.

11. Apparatus according to claim 9 or claim 10, wherein the modulated signal is tuned to the whole body mode of the panel.

12. Apparatus according to claim 9, wherein the panel is small and has an aspect ratio of substantially 3:

2.

13. Apparatus according to claim 9, wherein the panel stiffness and the output impedance of the actuator are arranged to deliver a force to the user'"'"'s finger tip of more than 30 mN.

14. Apparatus according to claim 13, wherein the force delivered to the finger tip is arranged to be in the range 30 to 500 mN.

15. Apparatus according to claim 9, comprising at least two distributed mode actuators attached to the panel and arranged to enhance the panel displacement at the touch location.

16. Apparatus according to claim 15, comprising digital signal processing for enhancing the panel displacement at the touch location.

17. Apparatus according to claim 9, comprising a visual display device associated with the bending wave panel.