Depressible Keys with Decoupled Electrical and Mechanical Functionality

• US 20160306437A1
• Filed: 04/15/2015
• Published: 10/20/2016
• Est. Priority Date: 04/15/2015
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Qu, Dayu, Camp, John S., Zhang, Chang, Chang, Ray L.
• Granted Patent: US 9,952,682 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 1/1662 Details related to the integrated keyboard
• CPC Class Codes: G06F 3/0202 Constructional details or processes of manufacture of the input device

Abstract

Systems and methods for decoupling the electrical and mechanical functionality of a depressible key are disclosed. The depressible key can include a non-contact proximity sensor, such as an optical sensor, to detect motion of the keycap. The output from the optical sensor is used to determine a distance, velocity, acceleration, and a force applied during a keypress.

Claims

1. A keyboard comprising:

a plurality of keys, each key comprising;

a keycap comprising an optically reflective bottom surface;

a travel mechanism coupled to the underside of the keycap; and

a non-contact proximity sensor comprising;

a light emitter oriented to emit light toward the reflective bottom surface; and

a light detector oriented to receive light reflected from the reflective bottom surface; and

a keyboard controller coupled to at least one non-contact proximity sensor.

2. The keyboard of claim 1, wherein at least one light emitter is configured to emit light in the infrared spectrum.

3. The keyboard of claim 1, wherein at least one light emitter is configured to emit light in the visible spectrum.

4. The keyboard of claim 3, wherein the at least one light emitter is configured to emit white light of selectable brightness.

5. The keyboard of claim 1, wherein at least one light emitter is configured to emit light in the infrared spectrum and light in the visible spectrum.

6. The keyboard of claim 1, wherein at least one light detector is configured to generate an electrical signal in response to receiving infrared light.

7. The keyboard of claim 1, wherein at least one light detector is configured to generate an electrical signal in response to receiving visible light.

8. The keyboard of claim 1, wherein the keyboard controller is configured to obtain an electrical signal from at least one light detector.

9. The keyboard of claim 8, wherein the keyboard controller is configured to determine an estimation of force applied to the keycap in response to the electrical signal.

10. The keyboard of claim 8, wherein the keyboard controller is configured to determine an estimation of velocity applied to the keycap in response to the electrical signal.

11. The keyboard of claim 8, wherein the keyboard controller is configured to determine an estimation of distance between the keycap non-contact proximity sensor in response to the electrical signal.

12. A depressible key comprising:

a keycap comprising an optically reflective bottom surface;

a travel mechanism coupled to the underside of the keycap;

a tactile feedback structure configured to collapse in response to a force applied to the keycap; and

an optical sensor comprising;

a light emitter oriented to emit light toward the reflective bottom surface; and

a light detector oriented to receive light reflected from the reflective bottom surface.

13. The depressible key of claim 12, wherein the optically reflective bottom surface comprises a polished metal material.

14. The depressible key of claim 12, wherein:

the travel mechanism is aligned to the geometric center of the keycap; and

the tactile feedback structure is nested within the travel mechanism.

15. The depressible key of claim 12, wherein the light emitter comprises a light emitting diode.

16. The depressible key of claim 12, wherein the light detector comprises a photodiode.

17. A method of detecting a press of a depressible key, comprising:

illuminating an underside of a keycap associated with the depressible key with a selected wavelength of light;

receiving an electrical signal corresponding to the amplitude of light reflected from the underside of the keycap; and

determining whether a characteristic of the electrical signal passes a threshold test associated with a press of the key.

18. The method of claim 17, further comprising:

determining at least one of a velocity and acceleration of the keycap from the electrical signal.

19. The method of claim 17, further comprising:

determining a force applied to the keycap based on the electrical signal.

20. The method of claim 17, wherein the selected wavelength of light is infrared.