Today an interesting patent from Nokia became public. They are trying to patent touch sensitive keypad with tactile feedback which many firms are already working on it. Hope we will see Nokia using this technology in their Lumia Windows Phone devicesÂ soon.
A keypad includes discrete keys formed by touch sensors or virtual keys on a touch sensitive area. The discrete or virtual keys are mechanically linked to a biased switch. The key that has been touched during a keystroke is identified through a signal from the touch sensors whilst a keystroke is recorded upon a signal from the biased switch. The combination of the touch sensors with a biased switch provides tactile feedback. The use of touch sensors or a touch sensitive area allows the keypad to be constructed with a substantially flush surface without parting lines.
Another patent related to keypad,
An apparatus including: a substrate; a keypad including a plurality of distinct rigid elongate keys wherein each elongate key includes: a first end portion supported by the substrate and a second end portion separated by a dimension of the elongate key from the first end portion, and suspended from the substrate in free space by the elongate key; and a plurality of switches, wherein each switch detects travelling towards the substrate of the second end portion of a respective one of the plurality of elongate keys in response to user actuation of the second end portion.