HP QMS 4060 - Manual (Page 146)

Halftones
QMS 4060 Print System Reference 5-4
Configuring the printer through the control panel is described in chap-
ter 4, “Printer Configuration,” of this manual.
Halftones
The ability of the printer to produce halftones allows you to add
scanned images or halftone graphics to your documents. This section
will explain some of the options available on the QMS 4060 for half-
tone printing.
What are Halftones?
Continuous tone scanned images have to be converted to dot pattern
images on a laser printer. Laser printers, like printing presses, only
have the ability to print patterns of dots controlled by turning on and
off the laser. Because of the limited resolving power of the eye half-
tones appear as continuous tone images. For an example hold a
newspaper photograph very close to your eyes to see the halftone
dots.
Halftone characteristics can be changed by settings available on your
QMS 4060 Print System. The following factors can be used to adjust
the halftone characteristics of your documents.
n
Printer resolution
n
Screen frequency and screen angles (Halftone types)
There can be some side effects to changing these factors. Factors
such as the number of gray levels, printer performance, and scanned
image quality can be affected.
Gray Levels
Gray levels are a progressive series of gray tones between black and
white. Gray levels are produced by varying the ratio of black to white
halftone dots. The number of gray levels depends on printer resolu-
tion and screen frequency.