Touch sensitive keypad with tactile feedback

• US 20070296702A1
• Filed: 06/21/2006
• Published: 12/27/2007
• Est. Priority Date: 06/21/2006
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Tompkin, Crispian, Strawn, Andrew, Davidson, Brian, Miles, Luke, Leith, Daren, Bradford, Simon, Bick, Andrew Raymond
• Granted Patent: US 8,139,035 B2
• Time in Patent Office: Days
• US Class Current: 345/169
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/1662 Details related to the integrated keyboard
• CPC Class Codes: G06F 1/169 the I/O peripheral being an integrated pointing device, e.g. trackball in the palm rest area, mini-joystick integrated between keyboard keys, touch pads or touch stripes G06F1/1643 takes precedence; constructional details of pointing devices G06F3/033
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 3/0202 Constructional details or processes of manufacture of the input device
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: H01H 13/85 characterised by tactile feedback features
• CPC Class Codes: H01H 2215/01 Part of spacer
• CPC Class Codes: H01H 2219/024 programmable
• CPC Class Codes: H04M 1/23 Construction or mounting of dials or of equivalent devices; Means for facilitating the use thereof by improving visibility H04M1/22
• CPC Class Codes: H04M 2250/22 including a touch pad, a touch sensor or a touch detector digitizers for touch screens G06F3/041

Abstract

A keypad includes discrete keys formed by touch sensors or virtual keys on a touch sensitive area. The discrete or virtual keys are mechanically linked to a biased switch. The key that has been touched during a keystroke is identified through a signal from the touch sensors whilst a keystroke is recorded upon a signal from the biased switch. The combination of the touch sensors with a biased switch provides tactile feedback. The use of touch sensors or a touch sensitive area allows the keypad to be constructed with a substantially flush surface without parting lines.

Claims

1. A keypad for use with an electronic device, said keypad comprising a plurality of discrete keys formed by touch sensors or a plurality of virtual keys in a touch sensitive area, said plurality of discrete or virtual keys being mechanically coupled to a biased switch that is activated by pressing any of said discrete or virtual keys.

2. A keypad according to claim 1, wherein said biased switch provides tactile and/or aural feedback.

3. A keypad according to claim 1, wherein said biased switch acts with a snap action.

4. A keypad according to claim 3, wherein the biased switch is a dome switch.

5. A keypad according to claim 3, wherein the discrete keys form a flush surface substantially without part lines.

6. A keypad according to claim 5, wherein said flat surface is provided with key graphics.

8. A keypad according to claim 1, wherein said keypad includes capacitive elements operatively coupled to said discrete keys.

9. A keypad according to claim 1, wherein said touch sensitive area is formed by a capacitive touch pad.

10. A keypad according to claim 1, wherein said touch sensitive area is formed by a touch screen.

11. A keypad according to claim 1, wherein the touch sensors or the touch sensitive area are disposed on one side of a plate member, and the plate member is coupled to the biased switch.

12. A keypad according to claim 11, wherein the biased switch is disposed under the plate member and pressure applied on the plate member results in pressure on the biased switch.

13. A keypad according to claim 12, wherein the biased switch is disposed between said plate member and a substrate.

14. A keypad according to claim 13, wherein the biased switch comprises a collapsible member disposed between the plate member and the substrate.

15. A keypad according to claim 14, wherein the collapsible member comprises a thin walled collapsible ring.

16. A keypad according to claim 15, wherein the collapsible ring comprises two ring members connected to one another by a fold line.

17. A keypad according to claim 13, wherein said biased switch establishes an electrical contact when the collapsible member collapses.

18. A keypad according to claim 13, wherein the biased switch comprises a resilient element and urges the plate member to an idle position

19. A keypad according to claim 13, wherein a force with a magnitude above a given threshold on said plate member causes said plate member to move from an idle position to a lower position or to a tilted position in which said biased switch establishes an electrical contact.

20. A keypad according to claim 19, wherein said plate member has a substantial amount of travel between the idle position and a position in which the biased switch establishes an electrical contact.

21. A keypad according to claim 1, further comprising a link mechanism converting a downward movement of one or of a plurality of discrete keys or of a plate member with virtual keys into a sidewards movement or into a rotational movement.

22. A keypad according to claim 21, wherein said link mechanism acts on the biased switch.

23. A keypad according to claim 22, wherein the link mechanism includes a transversely sliding plate member.

24. A keypad according to claim 23, wherein said sliding plate member is slidably suspended between two oppositely disposed guide rails.

25. A keypad according to claim 24, wherein the biased switch is disposed to face an edge of said sliding plate member.

26. A keypad according to claim 25, wherein said plate member comprises a plurality of recesses corresponding to the number of discrete keys, said recesses being provided with slanting edges that interact with slanting surfaces disposed on the underside of said discrete keys.

27. An electronic device comprising a processor controlling the operation of the device and a keypad according to claim 1, said processor being coupled to said keypad and said processor being configured to determine which of said discreet or virtual keys has been pressed from a signal from said touch sensors or touch plate, and said processor being configured to determine that a keystroke has been entered when said biased switch is activated.

28. A device according to claim 27, wherein the virtual keys are formed on a touch display and said processor is configured to display virtual keys on the touch screen.

29. A device according to claim 27, further comprising an orientation sensor, wherein the processor is configured to change the orientation of the virtual keys displayed on the touch screen in response to a signal from said orientation sensor.

30. A device according to claims 26, wherein said biased switch is mechanically linked to said plurality of discrete keys or to a plate member on which said virtual keys are disposed.

7. A keypad according to claim 7, wherein said key graphics are coupled to a lighting system, and the key graphics are substantially invisible when said lighting system is not active.

31. A method for registering keystrokes on a keypad or keyboard with a plurality of discrete or virtual keys, comprising identifying which of the keys has been struck with touch sensors, and determining that a keystroke has been made with a biased switch.

32. A method according to claim 31, further comprising the step of allowing said discrete or virtual keys to travel between an idle position in which the biased switch is not activated and a position in which the biased switch is activated.

33. A method according to claim 32 further comprising the step of providing a plurality of said discrete or virtual touch keys with tactile feedback by a mechanical link to the biased switch.