Ultra low travel keyboard

• US 9,178,509 B2
• Filed: 09/28/2012
• Issued: 11/03/2015
• Est. Priority Date: 09/28/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Bernstein, Jeffrey T.
• Primary Examiner(s): Obiniyi, Paul
• Application Number:
  US13/630,867
• Publication Number:
  US 20140091857A1
• Time in Patent Office: 1,131 Days
• Field of Search: 340/407.1, 340/407.2, 341/22, 341/27, 341/34, 345/156, 345/161, 345/168, 345/173
• US Class Current: 1/1
• 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 key for a computing device keyboard, comprising:

a key cap;

a force sensor at least partially contained within the key cap and coupled to an internal top surface of the key cap, the force sensor configured to measure an amount of force imparted to a surface of the key cap; and

an output line configured to carry a signal that indicates an amount of force imparted to the key cap through a force signal that varies based on the force measured by the force sensor;

wherein the force sensor is a strain gauge that changes a resistance by deforming in response to the force imparted to the surface of the key cap, the change in resistance being used to modulate the force signal, further comprising an input line configured to receive an excitation signal responsive to the force signal, and an actuator contained within the key cap, the actuator configured to excite the key cap in response to the excitation signal such that an opposing force is imparted to the key cap responsive to the force that is imparted to the surface of the key cap, wherein the actuator is a piezoelectric material that excites the key cap by deforming under a mechanical strain that is induced in the piezoelectric material in response to the excitation signal, and wherein the opposing force imparted to the key cap causes movement of the keycap.

2. The key of claim 1, wherein the force sensor is a resistive force sensor that responds to the force imparted to the surface of the key cap with a change in conductivity that is used to modulate the force signal.

3. The key of claim 1, wherein the force sensor is a capacitive force sensor that includes a compressible dielectric that changes the capacitance of the capacitive force sensor by deforming in response to the force imparted to the surface of the key cap, the change in capacitance being used to modulate the force signal.

15. The key of claim 1, wherein the actuator is coupled to the key cap by a first adhesive and the force sensor is coupled to the actuator by a second adhesive.

16. The key of claim 1, wherein the opposing force imparted to the key cap provides a tactile feedback responsive to the force that is imparted to the surface of the key cap.

4. A method of controlling a keyboard, comprising

receiving an input signal at a computing device from a keyboard, the input signal indicating an amount of force imparted to a key on the keyboard detected by a force sensor at least partially contained within a key cap of the key and coupled to an internal top surface of the key cap;

determining, by the computing device, if the key was pressed by determining if the amount of force imparted to the key exceeds a threshold amount; and

executing, by the computing device, a function that is associated with the key if the amount of force imparted to the key exceeds the threshold amount;

wherein the force sensor is a strain gauge that changes a resistance by deforming in response to the force imparted to the surface of the key cap, the change in resistance being used to modulate the force signal, further comprising an input line configured to receive an excitation signal responsive to the force signal, and an actuator contained within the key cap, the actuator configured to excite the key cap in response to the excitation signal such that an opposing force is imparted to the key cap responsive to the force that is imparted to the surface of the key cap, wherein the actuator is a piezoelectric material that excites the key cap by deforming under a mechanical strain that is induced in the piezoelectric material in response to the excitation signal, and wherein the opposing force imparted to the key cap causes movement of the keycap.

5. The method of claim 4, further comprising

providing feedback to the key press by transmitting an excitation signal from the computing device to the keyboard that causes a tangible excitation in the key.

7. The method of claim 4, further comprising

determining a key type for the key;

and

fetching a data value for the threshold amount used to determine if the key was pressed from a data structure that defines a plurality threshold amounts for various key types.

8. The method of claim 4, wherein the threshold amount is a first threshold amount, and the function associated with the key is a first function, the method further comprising

determining, by the computing device, if the key was deeply pressed by determining if the amount of force imparted to the key is greater than a second threshold amount that is greater than the first threshold amount;

and

executing, by the computing device, a second function associated with the key that is different from the first function if the amount of force imparted to the key was greater than the second threshold amount.

9. The method of claim 8, further comprising:

if the key was pressed, providing feedback to the key press by transmitting an excitation signal from the computing device to the keyboard that causes a tangible excitation of a first magnitude in the key; and

if the key was deeply pressed, providing feedback to the deep key press by transmitting an excitation signal from the computing device to the keyboard that causes a tangible excitation of a second magnitude in the key, wherein the first magnitude is greater than the second magnitude.

10. The method of claim 4, wherein the input signal is a first input signal and the key is a first key, the method comprising

receiving a second input signal at the computing device from the keyboard, the second input signal indicating an amount of force imparted to a second key on the keyboard;

determining, by the computing device, if both the first key and the second key were pressed by determining if the amount of force imparted to both the first key and the second key is greater than a threshold amount; and

executing, by the computing device, a command that is associated with the combination of the first key and the second key if the amount of force imparted to both the first key and the second key is greater than a threshold amount.

11. The method of claim 10, further comprising:

providing feedback to both the first key press and the second key press by transmitting an excitation signal from the computing device to the keyboard that causes a tangible excitation in both the first key and the second key.

12. The method of claim 4, wherein the input signal is a first input signal and the key is a first key, the method comprising

receiving a second input signal at the computing device from the keyboard, the second input signal indicating an amount of force imparted to a second key on the keyboard;

determining, by the computing device, that a finger is resting on the first key if the amount of force imparted to the first key is not greater than the threshold amount;

determining, by the computing device, that a finger is resting on the second key if the amount of force imparted to the second key is not greater than the threshold amount;

displaying a result of the command but not executing the command while a finger is resting on both the first key and the second key.

6. A method of controlling a keyboard, comprising

receiving an input signal at a computing device from a keyboard, the input signal indicating an amount of force imparted to a key on the keyboard detected by a force sensor at least partially contained within a key cap of the key and coupled to an internal top surface of the key cap;

determining, by the computing device, if the key was pressed by determining if the amount of force imparted to the key exceeds a threshold amount;

executing, by the computing device, a function that is associated with the key if the amount of force imparted to the key exceeds the threshold amount; and

providing feedback to the key press by transmitting an excitation signal from the computing device to the keyboard that causes a tangible excitation in the key, wherein the tangible excitation is of a first type that includes an initial excitation of a first magnitude that occurs for a predetermined duration after the key press occurs, and after the predetermined duration elapses no further excitations of the first magnitude occur while the force imparted to the key remains greater than the threshold amount, the method further comprising

determining, by the computing device, that a finger is resting on the key if the amount of force imparted to the key is not greater than the threshold amount;

providing feedback to the finger resting on the key by transmitting an excitation signal from the computing device to the keyboard that causes a tangible excitation of a second type in the key, the tangible excitation of the second type including a vibration that occurs so long as the force is imparted to the key and so long as the force imparted to the key does not exceed the threshold amount.

13. A method of controlling a keyboard, comprising

receiving an input signal at a computing device from a keyboard, the input signal indicating an amount of force imparted to a key on the keyboard detected by a force sensor at least partially contained within a key cap of the key and coupled to an internal top surface of the key cap;

in response to the receiving the input signal, executing, by the computing device, a function proportionally based on the amount of force that is imparted to the key, wherein the function is associated with the key;

wherein the force sensor is a strain gauge that changes a resistance by deforming in response to the force imparted to the surface of the keycap, the change in resistance being used to modulate the force signal, further comprising an input line configured to receive an excitation signal responsive to the force signal, and an actuator contained within the key cap, the actuator configured to excite the key cap in response to the excitation signal such that an opposing force is imparted to the key cap responsive to the force that is imparted to the surface of the key cap, wherein the actuator is a piezoelectric material that excites the key cap by deforming under a mechanical strain that is induced in the piezoelectric material in response to the excitation signal, and wherein the opposing force imparted to the key cap causes movement of the keycap.

14. The method of claim 13, further comprising

providing feedback by transmitting an excitation signal from the computing device to the keyboard that causes a tangible excitation in the key that is proportional to the force that is imparted to the key.