To better understand the method an example of text input using the MIK™ is shown on an animation below (only key "2" of standard phone keypad is shown for simplicity, input symbol is shown on the right side of the key, the ellipse shows movement of a finger, real movement can be much faster):

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NO TILT, NO JOYSTICK-KEYS.

Digits 0-9 and *, # are inputted by short-time touch (pressure) of the proper keys (100% legacy support). These symbols can also be inputted by stronger pressure on the keys. 

Other symbols, e.g. characters of divers alphabets can be inputted through either of the following simple manipulations within the key’s surface (as shown on the animation above):

(1)  Northward lateral movement of a finger on the key with the following release;

(2)  Eastward lateral movement of a finger on the key with the following release;

(3)  Southward lateral movement of a finger on the key with the following release;

(4)  Westward lateral movement of a finger on the key with the following release;  

Thus, each of the keys of standard telephone keypad allows inputting of at least five different symbols via one simple, intuitively clear, close to rectilinear lateral movement of a finger (or just touch of the central region of the key when inputting digits).  

Because of the nature of the finger movements (no significant pressure, no tap, one movement per symbol), the MIK™ SAVES HEALTH, especially to those who sends a lot of SMS's (mostly younger users).

Besides, the MIK™ is a WYSIWYG (What You See Is What You Get) device, what is a huge advantage before T9 and other predictive approaches. This greatly enhances Customer perception of the MIK™.

Using the MIK™, the user has as many as 60 keys (12 "vertical" keys, activated by touch of the key's centre,  plus 12x4 "horizontal" keys activated by outward movements starting in the centre of the key). And 60 independent keys is quite a lot, especially if compared to today's 12 keys sets present in majority of mobile phones.

As it was mentioned above, the MIK™  provides "legacy support" since layout of the MIK™ is similar to that of standard telephone keypad, especially when the touch sensitivity is provided over a plain mechanical keypad (this technology has been already developed by e.g. Cirque Corp.) what makes the MIK™ 100% familiar to the user. This is a very important moment for introduction of any input device into the mass market. We can see a lot of examples when the "fast and simple" text input methods penetrate into "mass mind" too slowly mostly because of too big difference between existing telephone keypad layout and the introduced ones.

As the experiments with the prototype show, it is not even necessary to position a finger on the central region of the key. Direction of the movement (North, East, South or West) and the key where the movement starts uniquely define the inputted symbol. For instance: key "2" - North as A, East as B, South as C, West reserved, the characters are also located accordingly on the key (A on the North, B on the East, C on the South) as shown on animation above.

So, no need to find the centre, just "get on the right key" what is a simple ergonomic task in this case (and the Fitt's law is OK here). In order to distinguish movement ("horizontal strokes", characters) from touch (0-9, #,*) the movement threshold was introduced. If the movement is not less than the threshold it is processed as the "horizontal stroke", otherwise it is processed as a touch. This simplifies the whole concept significantly (both realization and operation).

Actually, despite a relatively big number (total five) of symbols being inputted by a single key, the possibility of error is quite low since directions of lateral movement differ on 90 degrees what allows angle error within approximately plus/minus 45 degrees what is more than enough for predictable result. The same can be said about initial and final touch points of the lateral movement – since the central region can be easily visually and tactually (if the central region of the key is tactually distinguishable) defined by the user the errors with definition of other regions don’t lead to input errors in most cases. In fact if e.g. the outward motion finishes even on adjacent key (or even outside the keypad for the outer keys), correct central region positioning (due to tactual feedback and visual control) and correct angle of direction definition (due to wide span – plus/minus 45 degrees) allow deriving errorless conclusion about the user’s intentions.

As for a "big finger concern", ample distance between centers of the keys (at least 8 mm, this is enough for errorless input in most cases, and the keypad remains miniature) can be easily provided  and simultaneous touch of the peripheral regions of adjacent keys is not a problem (see above). Besides, the existing touch detecting methods allow deriving a central point of the touch region what is helpful as well, thus simultaneous touch of the peripheral regions of adjacent keys is not a problem.

Additionally, more complex lateral movements are possible (e.g. from central region of one of the keys to central region of another key, or zigzag movements, etc.) what has been already realized in the working prototype of the MIK™.

Being touch sensitive the MIK™ can also be used as a pointing device realizing pointing capabilities similar to those of the touchpad.  This allows elimination of navigation buttons, so leaving more real estate for the display in same compact housing of the mobile phone, what is another great advantage of the offered approach.

Another advantage of the MIK™ is its "no touch, no input" feature what allows not to use keypad lock at all.

By the way, the first prototypes of the MIK™ are based on the touchpads. As for the touch sensitivity over keypad itself, it is described in e.g. Nokia's US Patent Application No. 20020049070 ("User interface device", Inventor Andrew Raymond Bick, Filed August 29, 2001).

The MIK™ can also be built on the Pressure Sensitive Keypad™ (the PSK™, patent pending), developed by the author. More details of the PSK™ can be found here.

A very important advantage of the described here multi-directional symbol input is that all variety of symbols can be inputted just by thumb of the same hand which holds the radiotelephone, what being combined with other advantages shown above beats hands down all other “simple” ways of symbol input in the mobile phones (including those using stylus, or built-in full-set mechanical keyboards, or soft keyboards, etc.).