Daisy Wheel Printer Definition/Meaning:
A type of serial impact printer in which the font is
formed on the end of spring fingers that extend radially from a central hub. The
font carrier can be likened to the flower of the daisy and the spring fingers
are often referred to as petals. The font carrier is rotated by a servosystem
until the correct character is opposite the printing position and a single
hammer impacts it against the inked ribbon and paper. The carriage on which are
mounted the font and hammer - and usually the ribbon - is then moved to the next
printing position in the line.
The daisywheel printer was introduced by Diablo Systems Inc. in 1972 and
represented a considerable improvement in speed and reduction in mechanical
complexity compared to the golfball and other
typewriters that were used as low-speed printers at that time. The speed was
initially 30 characters per second with a repertoire of 96 characters.
Developments led to speeds of 65 cps for average text. In 1982 Diablo introduced
a machine that can have up to 192 characters on the type wheel; by overprinting
it is possible to form a further 250 characters. This development partially
overcomes the disadvantage - relative to matrix printers
- of the limited
character set Other developments have led to lower-cost but slower (12-20 cps)
units that are competitive with conventional and golfball typewriters. The print
quality achieved by the daisywheel printer is equal to that of very good
typewriters and they are used on word-processor systems for producing letters
and documents.
The print head and paper position can generally be incremented bidirectionally by control commands. This allows the features associated with
typesetting, such as proportional
spacing justification, subscript and superscript characters, etc., to be
achieved.
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