Keyboards with both individual and combination key output
Methods of providing input feedback in a device having a keyboard with a matrix of independent keys having associated switches arranged in rows and columns, wherein combinations of diagonally adjacent keys are associated with combination key outputs, and devices performing such methods. One method includes scanning for activated keys, providing provisional output to a user indicating that the activated key has been registered; continuing to scan the matrix; and, in response to activation of an adjacent key prior to release of the first activated key, providing final output to the user indicating that a combination of the first and adjacent keys has been registered, to the exclusion of the provisional output. Another features driving the rows in adjacent pairs while examining the columns for switch activation; and, in response to detecting switch activation in two adjacent columns while driving the rows in adjacent pairs, determining a combination key output.
1. A method of providing input feedback in a device having a keyboard with a matrix of interstitial key regions and raised independent key regions, the method comprising
scanning the matrix for activated key regions;
upon detection of a first activated key region, providing provisional output as visual feedback to a user indicating that the activated key region has been registered;
continuing to scan the matrix for activation of an adjacent key region prior to release of the first activated key region; and,
in response to activation of the adjacent key region prior to release of the first activated key region, providing a final output to the user to the exclusion of the provisional output.
2. The method of claim 1 wherein the final output is provided as visual feedback.
3. The method of claim 2 wherein the provisional output is also provided as audio feedback.
4. The method of claim 1 wherein scanning the matrix includes scanning rows and columns.
5. The method of claim 1 wherein scanning the matrix includes driving two adjacent rows simultaneously, seeking for two simultaneous output columns.
6. The method of claim 1 wherein continuing to scan the matrix for activation of an adjacent key region includes determining if a diagonally adjacent key region is activated.
7. The method of claim 1 including looking up a desired combination key in an internal table in response to activation of an adjacent key region prior to release of the first activated key region.
8. The method of claim 1 wherein providing provisional output includes storing the provisional output as raw data into a register.
9. The method of claim 1 wherein the provisional output is provided as feedback and wherein providing the provisional output includes
determining the provisional output upon detection of the first activated key region, and then
delaying a predetermined amount of time after the provisional output is determined before providing feedback.
10. The method of claim 9 wherein the predetermined amount of time is approximately 20 milliseconds.
11. The method of claim 9 wherein the amount of delay time is determined from measured time between key strokes and details of correction.
12. The method of claim 1 wherein the independent key regions of the keyboard have exposed surfaces elevated above exposed surfaces of interstitial regions of the keyboard between adjacent independent key regions that together form a key combination corresponding to a stored combination key output.
13. The method of claim 1 wherein the adjacent key region is one of the independent key regions.
14. The method of claim 1 wherein the final output indicates that a combination of the first and adjacent key regions has been registered.
15. The method of claim 1 wherein both the first activated and adjacent key regions are elevated above an interstitial key region.
16. The method of claim 1 wherein only the raised independent keys key regions have associated switches.
17. The method of claim 1 wherein the first activated and adjacent key regions comprise two raised key regions on either side of an interstitial key region.