Two part key cap for use in keyboard keys and methods for their manufacture
View Patent ↗A key assembly is for use in a keyboard of the type including a key guide having a planar translation effecting (PTE) feature. The key assembly includes a key base having a PTE mating feature configured to interact with the PTE feature during a key press, and a key cap configured to be attached to the key base. The key base is made of a first material and the key cap is made of a second material different from the first material. A conductive portion and/or a magnet may be wedged between or secured within the key base or the key cap.
1. A keyboard having a plurality of key assemblies and planar translation effecting (PTE) features, wherein each of at least a subset of the key assemblies comprises:
a key base including a PTE mating feature; and
a key cap having a top surface component configured to be contacted by an input object;
wherein the PTE mating feature is configured such that the key cap translates vertically and laterally in a planar manner relative to the PTE feature in response to the input object contact,
wherein the PTE mating feature comprises a first material and the top surface component comprises a second material different from the first material, and
wherein the first material is characterized by a relatively higher coefficient of sliding friction than the second material.
2. The keyboard of claim 1 , wherein the first material is characterized by a relatively higher lubricity than the second material.
3. The keyboard of claim 1 , wherein the key base and key cap are configured to be mechanically coupled together.
4. The keyboard of claim 3 , wherein mechanically coupled comprises at least one of a snap fit and an interference fit attachment.
5. The keyboard of claim 1 , wherein the PTE mating feature comprises a ramp.
6. The keyboard of claim 1 , wherein each of the subset of the key assemblies is configured to cooperate with a respective key guide including a first magnetic component, and further wherein the key assembly comprises a second magnetic component configured to magnetically cooperate with the first magnetic component to return the key assembly to a nominal position following a keystroke.
7. The keyboard of claim 6 , wherein the second magnetic component is substantially retained within the key cap.
8. The keyboard of claim 6 , wherein the second magnetic component is substantially retained between the top surface component and the key base.
9. The keyboard of claim 1 , wherein the top surface component comprises identifying indicia.
10. The keyboard of claim 1 , wherein the PTE mating feature comprises polytetrafluoroethylene.
11. The keyboard of claim 1 , further comprising a backlight configured to illuminate the top surface components from underneath, wherein each top surface component further comprises a substantially opaque layer outlining a unique identifying indicia.
12. The keyboard of claim 11 , wherein the substantially opaque layer is applied to the top surface component by at least one of painting and printing.
13. The keyboard of claim 1 , wherein the key assembly further comprises a conductive layer disposed between the top surface component and the key base.
14. The keyboard of claim 13 , further comprising:
a first plurality of capacitive sensor electrodes disposed underneath the key assemblies, each of the first plurality of capacitive sensor electrodes being configured to detect motion of a respective key assembly in response to downward force applied by the input object; and
a second plurality of capacitive sensor electrodes disposed underneath at least a subset of the key assemblies, each of the second plurality of capacitive sensor electrodes being configured to detect positional information about the input object interacting with a respective key.
15. The keyboard of claim 14 , wherein each conductive layer of each subset of key assemblies is configured to capacitively couple with a respective one of the second plurality of capacitive sensor electrodes.
16. The keyboard of claim 1 , wherein the key base is substantially translucent.
17. A key assembly for use in a keyboard of the type including a key guide having a planar translation effecting (PTE) feature, the assembly comprising:
a key base having a PTE mating feature configured to interact with the PTE feature during a key press, the key base made of a first material; and
a key cap configured to be attached to the key base and made of a second material different from the first material,
wherein the PTE mating feature comprises a first material and the top surface component comprises a second material different from the first material, and
wherein the first material is characterized by a relatively higher coefficient of sliding friction than the second material.
18. A method of assembling a keyboard having a plurality of key assemblies each configured to cooperate with a respective key guide having a planar translation effecting (PTE) feature, the method comprising:
inserting a key base including a PTE mating feature into the PTE feature of the key guide; and
attaching a key cap, having a top surface configured to be contacted by an input object, to the key base,
wherein the PTE mating feature comprises a first material and the top surface component comprises a second material different from the first material, and
wherein the first material is characterized by a relatively higher coefficient of sliding friction than the second material.