Print Mechanism Motion Control for Improved Registration for Character Erase
Original Publication Date: 1983-Sep-01
Included in the Prior Art Database: 2005-Feb-07
In daisy-wheel typewriters having a character erase function, because of the high registration requirements, it is necessary to erase a character with, as closely as possible, the same dynamic forces as were present when the character was printed. Disclosed is a method for accurately positioning the escapement system to insure reliable erase ribbon operation when performing erasures. (An erase ribbon may take the form of lift-off or cover up, and is sometimes referred to as "tape.") Typically, the movements that make up an erase operation are: 1. A movement of the space value in the direction opposite that of the print direction. At the same time, the ribbon is moved to the erase position and the target petal is selected. 2. A movement to the character with hammer fire but without ribbon or selection motion.