The Glancing-Pad is an innovative device used for type-writing. It is a functional analog of a computer keyboard. To work it a user makes a short glancing (flicking) motion with a finger over and onto the pad surface. The pad is capable of tracking the positions of four fingertips. Simple mental template is used to instruct the user in the ways of making a particular glancing motion. There are no fixed targets for the fingertips on the pad – the pad is flat and tactilely featureless. Glancing gives a single-handed operation the encoding agility better than the keyboard-typing, combined with a vastly superior performance and ergonomic advantages.
How does it work?
Glancing-Pad is equipped with a motion-path detector tracking the wiggly paths of four fingertips over the pad’s surface. To encode a symbol, a glide of a fingertip above the pad (a surface-parallel motion) is combined with the gentle touch (a glancing stroke) to the pad. Hand is not bound by the device’s configuration (there are no keys to locate), and the encoding stroke can be applied to the surface anywhere within the pad’s boundary.
With practice, the widely-ranging and inaccurate sweeps, typical of a novice operator, get scaled down to short and nimble flicks, improving the speed and efficiency of encoding. Glancing-pad offers great boost in performance by improving economy of the encoding motion.
The rules of encoding
The glancing motion is guided by a simple requirement to move one of the fingertips above the pad in order to indicate (1) a side of an ‘imaginary’ rectangle, (2) the motion direction (clockwise vs. counterclockwise). The encoding segment of the motion has to be completed by the touch to the pad.
The glancing touch that generates a symbol also induces the touch sensation in the user’s fingertip. Such mental input is used for critical adjustments of the fingertip motion trajectory, and the distance at which each fingertip glides above the pad. Altogether, the same hand motions that actuate the device, make us feel and control the action.
Motion track of two fingers
This figure illustrates the paths traced by the fingertips of two adjacent fingers. Three symbols are being encoded in succession. Only one finger at a time can encode a symbol, while other fingers follow the action passively. Because of the bio-mechanical coupling between the fingers, the paths of fingers’ motions appear similar. Two paths depicted in the figure, one drawn in grey and the other in red, share the same time period, i.e. the motions are synchronous. Notice that the encoding touches (indicated by oval blobs) occur in sequence, each at a different moment in time, with the touch 2 of the finger 2 following touch 1, and preceding touch 3 of finger 1.
With practice, a user may get better control over the initially widely extended glancing motions, improving the speed of encoding (shorter motions are faster). As the motions assume shorter range, a small contrasted marker placed at the tip of each finger, may help to reliably trace even the most diminutive motions; pudgy fingers – no problem!
Assigning symbols to glances
The pad’s decoder associates the side and direction-indicating segment of the motion track, with a symbol. Mental template composed of a set of 8 symbol-encoding trajectory patterns per finger is used to guide the glancing motions. That way 32 symbols may be encoded using four fingers of one hand.
Each of the 32 glances was assigned a letter of the alphabet in the simplest, most orderly manner. With experience, other alphanumeric character assignments and standards of encoding may emerge. As every pad is expected to be owned and worked by a single person, the user may adopt any non-standard scheme of encoding, making the pad unworkable for anyone beside the original owner.
Detailed description of the device can be found in the USPTO patent No. 7,038,659, of May 2, 2006.