Non Contact Positioning of Impact Printer Print Wheel Petal
Original Publication Date: 1980-Apr-01
Included in the Prior Art Database: 2005-Feb-13
In impact printers utilizing daisy-wheel-type print wheels, accurate positioning of the petal containing the character to be printed with respect to the print position on the document is a requirement. Traditional techniques simply rely on a rotary encoder on the selection motor which rotates the print wheel shaft to position the selected character with respect to the required print position on the document. More exacting apparatus utilizes mechanical detent means supplementing the encoder to position the petal. Such means, which are usually associated with the missile, act to detent or center the character petal to be struck as the missile approaches. Traditional encoder methods operate reasonably well if the petals on the wheel are not too long so that oscillation can be kept minimal.