Impact Printer

1
(No Transcript)
2

• Then most popular categories of impact printer

• Dot matrix printer.
• Daisy wheel printer.

3
Dot matrix printer

• With a microprocessor, the print head can be
• moved in steps of less than two hundredths of
• an inch.
• Hence, it is possible to use very closely
  arranged
• dot to represent a character, e.g., If the
  printer
• head has 24-pins,it is called 24 pins dot
  matrix
• printer.
• More dots give a sharper font and a higher
• print quality.

4

• Print head of an dot matrix printer.

• Typical fonts of dot matrix printer.

5

• A paper printed by dot matrix printer

6
Some modern models of dot matrix printer
7
Advantages of dot matrix printer

• It allows multiple copy printing using multiply
  paper.
• Ordinary paper can be used.

8
Disadvantages of dot matrix printer

• The quality of printout is rather poor because
  the characters is composed by dots in a matrix.
• The print head has to strike against the paper at
  high frequency, thus making the print rather
  noisy
• The matrix needles are very tiny and may be
  broken easily.

9
Daisy wheel printer

• Employs a print wheel with spokes
• extended outwards from the center,
• forming the petals of a daisy-like wheel.
• The print characters is embossed near the end of
  each
• petals.
• A daisy wheel has to be spun rapidly to select
• characters.

10
Advantages of daisy wheel printer

• It offers high quality printout which makes it
• very suitable for word processing.
• Print wheel can also be changed so that
• different types of font can be used in a same
• paper.

Disadvantage of daisy wheel printer

• The printing speed is relatively slow.

11
The End