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Electronic Keyboard Transposition Elimination Scanning Method Disclosure Number: IPCOM000068063D
Original Publication Date: 1979-Nov-01
Included in the Prior Art Database: 2005-Feb-20

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Loiselle, JT [+details]


Keyboards having electronic switch actuators are usually employed with processors which serially scan each key position in order to determine whether a switch has been actuated. It has been found that keyboard scans which take longer than 10 milliseconds can result in key transposition errors (e.g., the first key struck is sensed second, resulting in character transposition when utilized with a typewriter). Errors of this kind are usually caused between alternate hand key strokes because typing rhythm is not good between the hands, but is good between the fingers of the same hand. Transpositions mostly occur between characters of familiar words such as "the" or "and". Because of these factors, the characters that are most often transposed in the English language comprise about 25% of the total number of characters.