Pressure sensitive keys
Pressure sensitive key techniques are described. In one or more implementations, a device includes at least one pressure sensitive key having a flexible contact layer spaced apart from a sensor substrate by a spacer layer, the flexible contact layer configured to flex responsive to pressure to contact the sensor substrate to initiate an input, for a computing device, associated with the pressure sensitive key. At least one of the flexible contact layer or the sensor substrate are configured to at least partially normalize an output resulting from pressure applied at a first location of the flexible contact layer with an output resulting from pressure applied at a second location of the flexible contact layer that has lesser flexibility than the first location.
1. A pressure sensitive key of a keyboard, the pressure sensitive key comprising:
a sensor substrate having one or more conductors; and
a flexible contact layer spaced apart from the sensor substrate and configured to flex in response to an application of pressure to contact the sensor substrate, the flexible contact layer having a force sensitive ink disposed on the underside of the flexible contact layer and having:
a first sensing area that is configured to contact the sensor substrate using the force sensitive ink; and
a second sensing area that is configured to contact the sensor substrate using the force sensitive ink, the force sensitive ink in the second sensing area having a higher conductivity than the force sensitive ink in the first sensing area, the first sensing area and the second sensing area being configured to normalize signals generated at the first sensing area and the second sensing area.
2. The pressure sensitive key as recited in claim 1 , the force sensitive ink in the second sensing area having less resistance than the force sensitive ink in the first sensing area.
3. The pressure sensitive key as recited in claim 1 , the second sensing area surrounding the first sensing area.
4. The pressure sensitive key as recited in claim 1 wherein the sensor substrate includes a plurality of conductors configured to be contacted by the force sensitive ink at corresponding first and second sensing areas.
5. The pressure sensitive key as recited in claim 1 , wherein the sensor substrate includes one or more conductors that are configured to be contacted by the force sensitive ink at corresponding first and second sensing areas, the second sensing area of the sensor substrate configured to have increased conductivity in relation to the first sensing area of the sensor substrate through use of smaller conductors in the first sensing area of the sensor substrate than in the second sensing area of the sensor substrate.
6. The pressure sensitive key as recited in claim 1 , wherein the sensor substrate includes one or more conductors that are configured to be contacted by the force sensitive ink at corresponding first and second sensing areas, the second sensing area of the sensor substrate configured to have increased conductivity in relation to the first sensing area of the sensor substrate through use of larger gaps between conductors in the first sensing area of the sensor substrate than in the second sensing area of the sensor substrate.
7. The pressure sensitive key as recited in claim 1 , wherein an amount of the force sensitive ink applied to the second sensing area is greater than an amount of the force sensitive ink applied to the first sensing area.
8. The pressure sensitive key as recited in claim 7 , wherein the amount of the force sensitive ink applied to the second sensing area is applied using at least two layers and the amount of the force sensitive ink applied to the first sensing area is applied using fewer layers than the layers used at the second sensing area.
9. The pressure sensitive key as recited in claim 7 , the thickness of the force sensitive ink applied to the second sensing area being greater than the thickness of the force sensitive ink applied to the first sensing area.
10. A method of normalizing pressure inputs to multiple areas of a key of a keyboard, the method comprising:
receiving a first pressure input applied to a first location of a flexible contact layer of the key resulting in force sensitive ink disposed on the underside of the flexible contact layer in a first area contacting a sensor substrate having one or more conductors; and
receiving a second pressure input applied to a second location of the flexible contact layer of the key resulting in the force sensitive ink disposed on the underside of the flexible contact layer in a second area contacting the sensor substrate, the second pressure input being less pressure than the first pressure input, the force sensitive ink in the second area having a higher conductivity than the force sensitive ink in the first area the first area and the second area being configured to normalize signals generated at the first area and the second area.
11. The method as recited in claim 10 , the force sensitive ink in the second area having less resistance than the force sensitive ink in the first area.
12. The method as recited in claim 10 , the second area surrounding the first area.
13. The method as recited in claim 10 , wherein an amount of the force sensitive ink applied to the second area is greater than an amount of the force sensitive ink applied to the first area.
14. The method as recited in claim 13 , wherein the amount of the force sensitive ink applied to the second area is applied using at least two layers and the amount of the force sensitive ink applied to the first area is applied using fewer layers than the layers used at the second area.
15. The method as recited in claim 13 , the thickness of the force sensitive ink applied to the second area being greater than the thickness of the force sensitive ink applied to the first area.
16. A keyboard comprising multiple pressure sensitive keys configured to initiate inputs of a computing device, each of the multiple pressure sensitive keys comprising a flexible contact layer spaced apart from a sensor substrate by a spacer layer and having a force sensitive ink disposed on the underside of the flexible contact layer, the flexible contact layer configured to flex in response to an application of pressure such that the force sensitive ink contacts the sensor substrate to initiate an input, for a computing device, associated with the pressure sensitive key, the sensor substrate having one or more conductors that are configured to be contacted by the force sensitive ink, a first key of multiple keys being configured to contact the sensor substrate using the force sensitive ink and a second key of the multiple keys being configured to contact the sensor substrate using the force sensitive ink, the force sensitive ink at the second key having a higher conductivity than the force sensitive ink at the first key, the force sensitive ink at the first key and the force sensitive ink at the second key being configured to normalize signals generated at the first key and the second key.
17. The keyboard as recited in claim 16 , the keyboard having a QWERTY arrangement, the first key comprising an index finger key and the second key comprising a pinky key.
18. The keyboard as recited in claim 16 , the keyboard having a QWERTY arrangement, the second key having a smaller surface area than the first key.
19. The keyboard as recited in claim 16 , the keyboard having a QWERTY arrangement, the first key comprising an key in a home row of keys and the second key comprising a key closer to an edge of the computing device.
20. The keyboard as recited in claim 16 , the first key having a first sensing area that is configured to contact the sensor substrate using the force sensitive ink, and a second sensing area that is configured to contact the sensor substrate using the force sensitive ink, the force sensitive ink in the second sensing area having a higher conductivity than the force sensitive ink in the first sensing area.