Print; Principle Of Color Overlapping - Brother HL-4040CN Service Reference Manual

3.4

Print

3.4.1 Principle of Color Overlapping

The human eye distinguishes one color from others by receiving light's three primary colors
(Red, Green, Blue). When monochrome lights are received, each color can be sensed.
However, when two-color lights, red (R) and green (G), are received, they are recognized as
"yellow"; when three-color lights, red (R), green (G) and blue (B), are received, they are
recognized as "white." The fineness of coloration is perceived according to the nature of light.
For printed colors, the human eye can perceive them as various colors by distinguishing each
color light reflected off the surface of a sheet of paper.
(1) For "cyan," since the print absorbs red (R) light of the three colors, only green (G) light and
blue (B) light are reflected, the color on the print side is recognized as a cyan color. (See
the following figure (1).)
(2) "Magenta" absorbs green (G) light and reflects red (R) light and blue (B) light. (See the
following figure (2).)
(3) If cyan and magenta are mixed, cyan absorbs red (R) light and magenta absorbs green (G)
light, and only blue (B) light is reflected. The light is identified as "blue." (See the following
figure (3).)
Theoretically, if cyan, magenta and yellow are mixed, all the colors are not reflected and black
can be shown. However, a black mix is difficult to produce, and black is shown using black-
color paint for practical purposes. Using such a principle, color-absorbing paints are mixed to
allow many colors to be shown on the surface of a sheet of paper.
(1) Green+Blue
B
Reflected
(3) Blue
B
Reflected
Cyan toner + Magenta toner
Yellow
Green
G R
Reflected Absorbed
Cyan toner
G R
Absorbed Absorbed
Red
Magenta
White
Blue
Cyan
Fig. Ref2-15
(2) Red+Blue
B
Reflected
Magenta toner
Fig. Ref2-16
Ref. 2-19
G R
Absorbed Reflected
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