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9. Image menu
9.3.9
Input balance
Overview
•
•
9.3.9.1
Introduction to Input Balance
Introduction: Unbalanced color signals
When transporting signals, there is always a risk of deterioration of the information contained in the signals.
In case of information contained in the amplitude of the signals which is the case of data color signals (R, G, B),image 9-41 , we are
quite sure that the amplitude of these color signals is subject to alterations.
An example of alteration may be a DC component added to the signal, in the form of a DC offset repositioning the black level, since
this
black level
(
“brightness”
) will become crucial later on (clamping circuit) it will result in “black not being black”.
Another value that is subject to alteration is the amplitude of the signal, resulting in an altered “Gain” of the signal (
“white level”
or
contrast
).
The alterations of the three color signals will happen independently i.e. the colors will end to be unbalanced, image 9-42
B
Black level
0.7V
Image 9-41
Black level
Δ
G
ΔΒ
Δ
R
R
G
B
Image 9-42
One can conclude here that a good color tracking can only be met by using three previously (input) balanced
color signals
Analog Digital Conversion
The analog color signals must pass through an Analog/Digital conversion circuit prior to any digital processing in the PMP.
A typical ADC transforms the analog value into an 8 bit coded digital signal.
The graphic shows that when converting a signal containing a DC offset component the range of the converter is not optimally used.
Black level
Δ
R
ADC
0
255
i1 : superfluous information
i2 : video information
Image 9-43
78
R59770180 FLM HD20 11/07/2008
Summary of Contents for FLM HD20
Page 1: ...FLM HD20 User guide R59770180 00 11 07 2008...
Page 4: ......
Page 14: ...1 Safety 10 R59770180 FLM HD20 11 07 2008...
Page 46: ...5 Connections 42 R59770180 FLM HD20 11 07 2008...
Page 58: ...6 Getting started 54 R59770180 FLM HD20 11 07 2008...
Page 62: ...7 Start up of the Adjustment Mode 58 R59770180 FLM HD20 11 07 2008...
Page 72: ...8 Input menu 68 R59770180 FLM HD20 11 07 2008...
Page 97: ...9 Image menu Image 9 105 Image 9 106 Image 9 107 R59770180 FLM HD20 11 07 2008 93...
Page 98: ...9 Image menu 94 R59770180 FLM HD20 11 07 2008...
Page 112: ...10 Layout menu Image 10 56 108 R59770180 FLM HD20 11 07 2008...
Page 116: ...11 Lamp menu Image 11 11 Image 11 12 Image 11 13 112 R59770180 FLM HD20 11 07 2008...
Page 156: ...13 Projector control 152 R59770180 FLM HD20 11 07 2008...
Page 190: ...17 Removal of the projector covers 186 R59770180 FLM HD20 11 07 2008...
Page 194: ...18 Dimensions 190 R59770180 FLM HD20 11 07 2008...
Page 204: ...20 Troubleshooting 200 R59770180 FLM HD20 11 07 2008...
Page 212: ...21 Specifications 208 R59770180 FLM HD20 11 07 2008...
Page 214: ...22 Order information 210 R59770180 FLM HD20 11 07 2008...