Transcript Classroom Expectations

Non Impact Printer
Introduction
The modern xerographic
process used today was
pioneered by Chester
Carlson
Chester
Carlson
developed the first mass
produced office copier
with
the
Haloid
Company, which later
became Xerox.
The first xerographic image
First commercial photocopier
1938 Chester Carlson made
the prototype photocopier
Cost per Page
$1.00
Units
$0.80
$0.60
Color LP
Color IJ
$0.40
$0.20
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96
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99
20
00
20
01
$0.00
Year
HP Printer Cost Comparison
$4,500
$4,000
$3,500
$3,000
$2,500
Monochrome
$2,000
Color
$1,500
$1,000
$500
$0
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2006
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Laser Printers
• Interaction of mechanical, electrical and optical
technologies
• Use toner, a dry, powdered electrically charged ink
• Performs various steps in printing process
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Non Impact Printer
How its works?
The Six Stages of Operation in a Laser
Printer include:
Cleaning
Conditioning
Writing
Developing
Transferring
Fusing
Six Steps of Laser Printing
1. Cleaning
2. Conditioning
3. Writing
4. Developing
5. Transferring
6. Fusing
Take place inside toner
cartridge
How a Laser Printer Works
• Cleaning
 Drum is cleaned of residual toner and electric charge
• Conditioning
 Drum is conditioned to contain high electrical charge
• Writing
 A laser beam discharges a lower charge only to places
where toner should go
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How a Laser Printer Works
• Developing
 Toner is placed on the drum where charge has been
reduced
• Transferring
 Strong electrical charge draws toner off the drum onto the
paper
 Takes place off the drum
• Fusing
 Heat and pressure fuse toner to the paper
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Step 1: Cleaning
• The drum is cleaned of any residual toner and electrical charge
Step 2: Conditioning
The drum is conditioned to contain a high
electrical charge. This drum assembly is made out
of highly photoconductive material that is
discharged by light photons.
Step 3: Writing
As the drum revolves, the printer shines a tiny laser
beam across the surface to positively charge certain
points. In this way, the laser "draws" the letters and
images to be printed as a pattern of electrical charges
, an electrostatic image.
Step 3: Writing
• Data from PC is received by formatter (1)
and passed to DC controller (2) which
controls laser unit (3)
• Scanning mirror (4) is turned clockwise by
scanning motor
• Laser beam is reflected off scanning mirror,
focused by focusing lens (5) and sent to the
mirror (6)
• Mirror deflects laser beam to a slit in the
removable cartridge and on to the drum (7)