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Items such as lumens collected out of the 
lam
Illumination Efficiency 
age by 
spli
p, optical system efficiency, color wheel 
efficiency, and screen efficiency impact the 
brightness of the display.  The screen 
brightness is simply the efficiency of the 
optical system multiplied by the collected 
lumens and the screen gain.  Improving any 
of the efficiencies in the optical path will 
result in an improvement of the screen 
brightness. 
Improving 
Lamp based displays render an im
tting the white spectrum of the lamp into 
the three primary colors, red, green, and 
blue.  In order to achieve the standard color 
gamut required for TVs and projectors, the 
generation of the red, green, and blue light 
components does not utilize the entire 
energy spectrum available from the lamp.  
This light loss is a result of the fact that parts 
of the lamp energy are not contained within 
the red, green, and blue filters used to render 
the image (reference Figure 3).   
Figure 3 – Spectral Energy Distribution of a 
olor™ technology resolves 
this
typical Lamp 
BrilliantC
 problem through the utilization of 
additional color filters.  In Figure 3, there is 
a significant amount of lamp energy that is 
not utilized at the 580nm wavelength.  This 
energy can be recaptured through the use of 
a yellow filter.  Also, a cyan filter will 
improve the efficiency in the 500nm region.  
Designing a projection system that uses a 5-
color illumination system can improve the 
end brightness by as much as 50%.  Table 1 
shows the improvement that can be gained 
in a DLP® display system using the new .45 
720p DMD and a 5-color wheel. 
 Common 
Color 
Wheel 
5 Color 
Wheel 
Collected 
Lumens at the 
DMD 
3375 3375 
Optical 
Efficiency 
35.8% 35.8% 
Color Wheel 
Efficiency 
16.5% 24.7% 
Screen Gain 
Factor 
4.7 4.7 
Screen 
Diagonal 
60 60 
Luminance 
(Nits) 
300 450 
Luminance 
Gain 
baseline 50% 
Table 1  -- Luminance Gain from BrilliantColor™ 
in an Example .45 720p system 
 
Improved Color Gamut 
In addition to improved system 
illumination efficiency, BrilliantColor™ 
technology also allows for a much broader 
color gamut.  The color gamut of a red, 
green, blue display is defined as the area of 
colors bounded by the triangle whose points 
are defined by the colorimetric settings of 
the red, blue, and green filters.  Any color 
that can be displayed on the system is some 
combination of the red, green, and blue 
colors.  Though this color space is suitable 
for many applications, it does not allow for 
the creation of vivid colors such as yellow 
and cyan.  The reason for this is that the 
vivid yellow (or cyan) that we frequently see 
in nature is outside of the area bounded by 
the triangle.  Adding additional color to the 
rendering engine allows us to expand the 
triangle into a wider polygon resulting in a 
greater selection of colors.  Figure 4 shows 
the triangle used by the Rec. 709 color 
standard used by many televisions today.  
 
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