Ultra low travel keyboard

• US 9,997,306 B2
• Filed: 10/30/2015
• Issued: 06/12/2018
• Est. Priority Date: 09/28/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Bernstein, Jeffrey T.
• Primary Examiner(s): Pham, Toan N
• Application Number:
  US14/928,465
• Publication Number:
  US 20160049265A1
• Time in Patent Office: 956 Days
• Field of Search: 3404071, 3404072, 200341, 29622
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user
• CPC Class Codes: G06F 3/0202 Constructional details or processes of manufacture of the input device
• CPC Class Codes: G06F 3/023 Arrangements for converting discrete items of information into a coded form, e.g. arrangements for interpreting keyboard generated codes as alphanumeric codes, operand codes or instruction codes
• CPC Class Codes: H01H 13/14 Operating parts, e.g. push-button
• CPC Class Codes: H01H 2215/00 Tactile feedback
• CPC Class Codes: H01H 2221/036 Return force
• CPC Class Codes: H01H 2239/052 Strain gauge
• CPC Class Codes: H03K 17/962 Capacitive touch switches

Abstract

A keyboard or keyboard key that has a force sensor that measures the force imparted to the key when a user presses the key or rests a finger on a key. Key embodiments may also include an actuator that excites the in order to provide feedback to the user in accordance with various feedback methods disclosed herein.

Claims

1. A keyboard key, comprising:

a key cap;

a combined force sensor and actuator coupled to the key cap, comprising;

a first conductive plate;

a second conductive plate; and

an electroactive polymer positioned between the first and second conductive plates;

wherein the combined force sensor and actuator;

produces an electrical response when the electroactive polymer is deformed due to a force applied to the key cap; and

provides an excitation of the key cap in response to the force applied to the key cap and an electrical signal provided to the electroactive polymer.

2. The keyboard key of claim 1, wherein the first and second conductive plates compress the electroactive polymer to produce the electrical response.

3. The keyboard key of claim 1, wherein a magnitude or an amplitude of the electrical response is used to estimate an amount of the force applied to the key cap.

4. The keyboard key of claim 1, wherein the combined force sensor and actuator produces the electrical response when the force applied to the key cap meets or exceeds a threshold amount.

5. The keyboard key of claim 4, wherein the threshold amount corresponds to a certain amount of deformation of the electroactive polymer.

6. The keyboard key of claim 1, wherein the second conductive plate is attached to the keyboard.

7. The keyboard key of claim 1, wherein internal strains in the deformed electroactive polymer undeform the electroactive polymer when the force applied to the key cap is no longer applied.

8. A key for a computing device keyboard, comprising:

a key cap defining an internal area;

a combined force sensor and actuator fitted at least partially within the internal area of the key cap, the combined force sensor and actuator including;

at least two conductors; and

an electroactive polymer positioned between the at least two conductors;

wherein the combined force sensor and actuator;

outputs a signal indicative of an amount of a force applied to the key cap that deforms the electroactive polymer; and

moves in response to the force applied to the key cap and an electrical signal applied to the electroactive polymer to provide a tactile output.

9. The key of claim 8, wherein the signal is an electrical response of the electroactive polymer.

10. The key of claim 8, wherein the signal is produced based on an electrical response of the electroactive polymer.

11. The key of claim 8, wherein the key cap transfers the force applied to the key cap to the combined force sensor and actuator.

12. The key of claim 8, wherein the combined force sensor and actuator is connected to an internal top surface of the key cap.

13. The key of claim 8, wherein the computing device analyzes the signal to determine whether the key is pressed.

14. The key of claim 8, wherein a height of the combined force sensor and actuator changes based on the amount of the force applied to the key cap.

15. A input device, comprising:

a cap defining an interior;

a first conductive plate bonded to the interior of the cap;

an electroactive polymer coupled to the first conductive plate; and

a second conductive plate coupled to the electroactive polymer such that the electroactive polymer is positioned between the first and second conductive plates;

wherein;

a force applied to the cap compresses the electroactive polymer;

compression of the electroactive polymer produces a force signal proportional to an amount of the force applied to the cap; and

the electroactive polymer physically deforms in at least one direction to provide a tactile output in response to receiving an excitation signal.

16. The input device of claim 15, wherein the at least one direction in which the electroactive polymer physically deforms is opposite to a direction in which the force applied to the cap is applied.

17. The input device of claim 15, wherein the electroactive polymer returns to an uncompressed state when the force applied to the cap ceases.

18. The input device of claim 15, wherein the first conductive plate is bonded to the interior of the cap by adhesive.

19. The input device of claim 15, wherein deformation of the electroactive polymer in the at least one direction moves the cap.

20. The input device of claim 15, wherein the electroactive polymer receives the excitation signal when the electroactive polymer is compressed a certain amount.