Browse Prior Art Database

Use of Unused Keyboard Matrix Coordinates and Keyboard Recognition Method

IP.com Disclosure Number: IPCOM000109756D
Original Publication Date: 1992-Sep-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 1 page(s) / 46K

Publishing Venue

IBM

Related People

Sugi, H: AUTHOR

Abstract

Disclosed is a keyboard scan control method for utilizing unused or idle coordinates on the keyboard scan/drive matrix as flags, and for recognizing the types of a key layout of a mechanical keyboard by using one of the flags.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 69% of the total text.

Use of Unused Keyboard Matrix Coordinates and Keyboard Recognition Method

       Disclosed is a keyboard scan control method for utilizing
unused or idle coordinates on the keyboard scan/drive matrix as
flags, and for recognizing the types of a key layout of a mechanical
keyboard by using one of the flags.

      A keyboard scan controller of a portable personal computer
detects "pressed" and "released" conditions of each key on the
keyboard through the sense lines and the drive lines.  Coordinates on
the matrix represent key positions.  The way that the sense lines and
the drive lines are interlaced, and the way that the coordinates are
assigned to key positions, vary depending upon the type of the
keyboard.  The keyboard scan controller must have the above
information of the connected mechanical keyboard for correctly
generating scan codes which are to be sent to the keyboard/auxiliary
device controller.

      Some of the coordinates are not assigned to any key position.
The unused coordinates may be used for other purposes.  They may be
used as flags for indicating some information.

      The "pressed" contact may be made permanently on any unused
coordinate.  Some coordinates have the permanently "pressed" contact.
The rest of the unused coordinates in the flag have the permanently
"released" contact.  A multiple number of unused coordinates may be
assigned to a flag in that way.

      As its values, a flag has a number of combinations of
c...