Push button with haptic feedback
Mechanical key design for keyboards often includes rubber or metal dome switches along with scissor mechanisms that offer a desirable feel and overall performance or achieve the key travel necessary to meet shrinking overall keyboard thickness specifications, but not both. Haptic feedback devices offer a user sensory feedback signifying a selection has been made without any physical travel of a keypad, but also may not offer the user a desirable feel and overall performance. The following describes in detail keys or push buttons that offer the user a desirable feel and performance, while meeting shrinking overall keyboard thickness specifications.
1. A push button comprising:
a spring element with a user-perceptible physical travel upon depression of the push button;
a haptic element that simulates additional travel of the push button upon depression of the push button as the spring element collapses; and
a switch that triggers the haptic element at a point along the physical travel of the spring element, wherein the haptic element produces a different haptic response dependent on which of a depressing direction and a releasing direction of the physical travel of the push button triggered the haptic element, and wherein the point is one of multiple points along the physical travel of the push button that trigger the haptic element.
2. The push button of claim 1 , wherein the spring element also includes one or both of a scissor mechanism and a resiliently compressible pad.
3. The push button of claim 1 , wherein the haptic element includes one or more of an unbalanced motor, a piezoelectric device, an electrostatic device, and an ultrasonic device.
4. The push button of claim 1 , wherein the haptic element produces a different haptic response dependent on which of the multiple points along the physical travel of the push button triggered the haptic element.
5. The push button of claim 1 , further comprising:
a keycap that provides an interface for a user to depress the push button.
6. The push button of claim 1 , wherein the user-perceptible physical travel exceeds 0.2 mm.
7. The push button of claim 1 , wherein the push button is one of an array of push button keys on a keyboard.
8. The push button of claim 1 , wherein a haptic response to be generated by the haptic element is selected from a group of available varying haptic responses depending on which of the depressing direction and the releasing direction of the physical travel of the push button triggered the haptic element.
9. The push button of claim 1 , wherein the spring element is a metal dome spring element.
10. The push button of claim 1 , wherein a combination of the user-perceptible physical travel and the simulated additional travel of the push button is between 0.4 mm and 0.8 mm.
11. A method for providing haptic feedback, the method comprising:
detecting a user-perceptible physical travel of a push button, including a collapse of a spring element of the push button;
actuating a haptic element in response to reaching a point along the physical travel of the push button as the spring element collapses, wherein the point is one of multiple points along the physical travel of the push button that actuate the haptic element;
selecting a haptic response from a group of available haptic responses depending on which of a depressing direction and a releasing direction of the physical travel of the push button actuated the haptic element; and
transmitting the selected haptic response from the haptic element via the push button to a user to simulate additional travel of the push button.
12. The method of claim 9 , further comprising:
selecting the haptic response from a group of available haptic responses depending upon which of the multiple points is reached by the push button.
13. The method of claim 9 , wherein the user-perceptible physical travel of the push button is caused by the user depressing the push button.
14. The method of claim 9 , wherein the user-perceptible physical travel of the push button exceeds 0.2 mm.
15. The method of claim 9 , wherein the push button is one of an array of push button keys on a keyboard.
16. The method of claim 11 , wherein the spring element is a metal dome spring element.
17. The method of claim 11 , wherein a combination of the user-perceptible physical travel and the simulated additional travel of the push button is between 0.4 mm and 0.8 mm.
18. A keyboard comprising:
an array of keys;
an array of spring elements, each spring element oriented below one of the keys with a user-perceptible physical travel upon depression of the key; and
an array of haptic elements, each haptic element also oriented below one of the keys simulating additional travel upon depression of a key as an associated spring element collapses; and
an array of switches, each switch triggering one of the haptic elements at a point along the physical travel of an associated spring element, wherein the haptic elements produce a different haptic response dependent on which of a depressing direction and a releasing direction of the physical travel of a key triggered an associated haptic element, and wherein the points are each one of multiple points along the physical travel of an associated spring element that triggered an associated haptic element.
19. The keyboard of claim 18 , wherein a haptic element produces a different response dependent on which of multiple points along a physical travel of an associated spring element triggered the haptic element.
20. The keyboard of claim 18 , wherein the spring elements are metal dome spring elements.
21. The keyboard of claim 18 , wherein a combination of the user-perceptible physical travel and the simulated additional travel of each of the array of keys is between 0.4 mm and 0.8 mm.