Keyboard overlay that improves touch typing on small touch screen devices

A keyboard overlay for use with a virtual touch screen keyboard having a plurality of virtual keys, wherein the virtual keys have virtual key centers laterally spaced apart in an East-West direction from each other, the overlay comprising:

• a base configured to be coupled to the virtual touch screen keyboard;
• and
• a plurality of overlay key structures, wherein individual overlay key structures have overlay key centers that are within active areas of the corresponding virtual keys, and wherein at least a subset of the overlay key structures are arranged such that the overlay key centers of the subset are offset relative to the virtual key centers of corresponding virtual keys, wherein the virtual keyboard has a QWERTY layout, wherein the overlay key centers of at least the A, S, D, K, L and “;” overlay key structures are laterally offset with respect to the virtual key centers of the A, S, D, K, L and “;” virtual keys, respectively, and wherein the lateral offset between the overlay key center of the A overlay key structure and the virtual key center of the A virtual key is greater than the lateral offset between the overlay key center of the D overlay key structure and the virtual key center of the D virtual key.

A keyboard overlay for use with a virtual touch screen keyboard having a plurality of virtual keys, wherein the virtual keys have virtual key centers laterally spaced apart from each other, the overlay comprising:

• a base configured to be coupled to the virtual touch screen keyboard;
• and
• a plurality of overlay key structures, wherein individual overlay key structures have overlay key centers that are within active areas of the corresponding virtual keys, and wherein at least a subset of the overlay key structures are arranged such that the overlay key centers of the subset are offset relative to the virtual key centers of corresponding virtual keys, wherein the offsets are elevational offsets in a North-South direction.