Touch Sensitive Device

• US 20120038568A1
• Filed: 02/12/2010
• Published: 02/16/2012
• Est. Priority Date: 02/16/2009
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: New Transducers Limited (Alphabet Inc.)
• Inventors: Colloms, Martin, Whitwell, Timothy Christopher Johnson
• Granted Patent: US 9,804,673 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: Y10T 29/49004 including measuring or testing of device or component part

Abstract

A method of making a touch-sensitive data entry screen of the kind arranged to provide haptic response to a user via at least one electromechanical exciter coupled to the screen, comprising analysing the mechanical and electromechanical coupled system represented by the data entry screen and the at least one exciter, and selecting values of parameters of the coupled system to provide a required displacement and acceleration of the screen at low frequency in response to human touch.

Claims

1. A method of making a touch-sensitive data entry screen of the kind arranged to provide haptic response to a user via at least one electromechanical exciter coupled to the screen, comprising resiliently mounting the touch sensitive data entry screen on a suspension, analysing the mechanical and electromechanical coupled system represented by the data entry screen, the suspension and the at least one exciter, and selecting values of parameters of the coupled system to provide a required displacement and acceleration of the screen at low frequency in response to human touch.

2. A method according to claim 1, wherein the selection of values comprises improving the electrical efficiency of the coupled system.

3. A method according to claim 1, wherein the selection of values comprises reducing the mechanical footprint of the coupled system.

4. A method according to claim 1, applied to a screen having a size of at least 200 mm.

5. A method according to claim 1, wherein the screen has a mass of at least 200 gms.

6. A method according to claim 1, wherein the required screen acceleration ranges from 5 to 50 m/s.

7. A method according to claim 6, wherein the acceleration is of the order of 20 m/s.

8. A method according to claim 1, wherein the analysis comprises analysing the resonance of the resiliently mounted screen.

9. A method according to claim 1, wherein the analysis comprises analysing the resonance of the or each exciter.

10. A method according to claim 1, wherein the analysis comprises analysing both screen surface and exciter coupled resonance.

11. A method according to claim 1, comprising coupling the or each exciter to excite the screen into out-of-plane movement.

12. A method according to claim 1, comprising coupling the or each exciter to excite the screen into in-plane movement.

13. A method according to claim 1, comprising coupling the or each exciter to excite the screen into rocking displacement.

14. A method according to claim 1, comprising selecting the or each exciter to be of the magnetically polarised or piezoelectric kind.

15. A method according to claim 1, comprising arranging a plurality of exciters to operate in a co-ordinated fashion.

16. A method according to claim 1, comprising providing a haptic signal to the or each exciter that is complex to provide additional information to the user.

17. A method according to claim 1, comprising employing a switching amplifier to feed haptic signals to the or each exciter.

18. A method according to claim 17, comprising arranging the switching amplifier to output a signal in the form of a low pass filtered waveform.

19. A method according to claim 18, wherein the waveform at least approximates to a square waveform.

20. Touch screen apparatus having haptic response to a user made by the method of claim 1.

21. Apparatus according to claim 20, comprising apparatus for producing an acoustic signal.

22. Apparatus according to claim 21, comprising a bending wave loudspeaker.

23. Apparatus according to claim 20, comprising an electronic display.

24. Apparatus according to claim 20, comprising a switching amplifier for feeding haptic signals to the or each exciter.