Print Modes; Figure 5-12 Print Modes And Printing Dots - Tektronix Phaser 550 Service Manual

Print modes

The printer features five print modes: Presentation, Fast Color, Standard,
Enhanced, and Premium. Standard, Presentation and Fast Color mode is 600 x
600 dpi printing. Enhanced mode is 1200 x 600 dpi printing. Premium mode is
1200 x 1200 dpi printing.
If no motion were involved, the laser dot produced would be an ovoid shape,
measuring about 50 microns wide by 55 microns tall. In practice, to print a dot,
the sweeping laser beam turns on long enough to create a roughly circular dot.
In Standard, Presentation and Fast Color 600 dpi (horizontal and vertical)
printing mode, the laser pulses often enough to produce 600 dots or pixels per
inch. The area allowed for a pixel is 42 microns square. Toner particles attracted
to the laser dot measure about 8 microns in size.
For Enhanced mode, the laser pulses often enough to produce 1200 dots or
pixels per inch. Dots are potentially laid down horizontally every 21 microns;
obviously this allows for a great deal of dot overlap. Controlling the amount of
overlap, by delaying the firing of the laser pulse, achieves grayscaling.
Premium mode 1200 dpi (horizontal and vertical) printing is achieved by cutting
in half the speed of the photoconductive and accumulator belts and the paper
transport. In addition the laser energy is lowered to 0.3 mW and the laser pulse
rate is doubled. Controlling the amount of horizontal and vertical overlap of the
dots results in even finer grayscaling.
55µ
50µ
0.5mW
0.3mW

Figure 5-12 Print modes and printing dots

42µ
70% duty cycle of
laser beam produces
fully saturated dots
21µ
Theory of Operation
600 dpi
printing
1200 dpi
printing
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Service Manual 5-15
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