Zebra Technologies P640I - Manual (Page 13)

Introduction
Printing basics
980541-001 Rev. A P640i Card Printer User Guide 3
Printing basics
This is the usual pattern for a P640i Printer
ribbon. Y, M and C are the three “dye sub”
process colors. The K panel is for infrared-
readable bar codes and other data, usually on
the back of the card. A second K panel
(YMCKK) is sometimes provided to allow
black resin printing on both sides of the card.
As the ID card is driven through the print
station, the color ribbon is metered out from
the supply roll at the same speed. Each color
reqires a separate “pass” of the card. The black
dots at the bottom edge of the print head depict
the heating elements - in practice, at 300 to the
inch, they are too small to be seen with the
naked eye.
Color migrates from the dye ribbon onto the ID card,
the spread of the dye depending on the amount of heat
applied by the print head element. Each time it comes to
a dye panel boundary, the print head lifts to allow the
card to back up, then lowers again to print the next
color.
The K (black) panel is a resin that “mass transfers”
onto the surface of the card, instead of migrating into
it. With mass transfer the printer has little control over
a pixel’s size or density - it’s either there or it isn’t. K
printing is used for bar codes because it is machine
readable, whereas YMC dyes are not.
What makes the P640i a different kind of
printer
The print station in the P640i has no pinch rollers that need cleaning to maintain accuracy
C
Cyan
Dye M
Magen-
ta Dye
Y
Yellow
Dye
K
Black
Resin
Print
head
Color
ribbon
Card
Card
Print
head
Card
Print
head