Hitachi 46W500 Training page 38

DP-3X CHASSIS VIDEO SIGNAL PATH NTSC EXPLANATION
(Continued from page 03-01)
MONITOR OUT FROM IV01: Composite video is output pin 41. S-Out Y pin 39, S-Out C pin 37.
COMPOSITE VIDEO PATH:
When a composite input is selected, it must be broken down into it respective parts, Y and C. This is accomplished for the
Main video by the 3D Y/C and for the PinP (Sub) picture by the 2-Line Comb filter.
MAIN: The Main composite output is routed out of the Selector IC IV01 pin 44 to QV14. Then through the video low pass
filter comprised of QY01, QY02, and QY04. It arrives at the 3D Y/C chip IY01 pin 93. Here the composite video is separated
into Y/C 3D enhanced, and output on the following pins, Y from pin 89 and C from pin 86.
NOTE: Sync for the Microprocessor is routed out pin 44 of IV01 to QV13.
Y COMPONENT FROM THE 3D Y/C (For Composite In).
The Y component is then routed through a low pas filter comprised of QY09, LPF XY01, QY10, and QY12 into the Main
Video/Chroma Processor IC IY04.
Note too that the Y component is also routed into the PinP (Sub) Video/Chroma Processor IC IY03 pin 2. This is for when the
customer presses the Swap button when the PinP Sub window is on.
C COMPONENT FROM THE 3D Y/C : (For Composite In).
The C component is then routed through a low pas filter comprised of QY13, LPF XY02, QY14, and QY15. Then the chroma
must be routed through the TILT circuit. This circuit compensates for the phase relationship of flesh tones between composite
and component. This circuit is comprised of QY16 and QY17. Not shown is the switch that enables this phase rotation circuit.
The output control is from the selector IC IY04 pin 8 to QY19. From QY17 the Chroma component is routed into pin 16 of
the Main Video/Chroma Processor IC IY04. Note too that the Chroma component is also routed into the PinP (Sub) Video/
Chroma Processor IC IY03 pin 16. This is for when the customer presses the Swap button when the PinP Sub window is on.
S-INPUT 3, 4 and/or 5:
When the S-Input is selected, it is already separated into Y and C components. In this case, Y is routed directly into the Main
Video Chroma Processor IY04. It is output from the Selector IC IV01 pin 44, through QV14 and into the Main Video
Chroma Processor IY04 pin 4. The Chroma component is output from the Selector IC IV01 pin 47, through QV16, QV17,
and into the Main Video Chroma Processor IY04 pin 19.
The responsibility of IY04 is to now convert the Y/C components of the Main picture into a usable format for the Flex Con-
verter. The Flex Converter FC4 utilizes component inputs Y Pr/Pb or Y Cr/Cb. IY04 outputs only NTSC, so it's outputs are
Y Cr/Cb. Y from pin 24, Cr from pin 22, and Cb from pin 23.
Y is then routed through QY29 to the connector PST2 pin 40.
Cr is then routed through QY30 to the connector PST1 pin 37.
Cb is then routed through QY28 to the connector PST1 pin 38.
(See the Component Video Signal Path for continuation).
PinP (Sub) Video Path:
The PinP (Sub) composite video is output from the Selector IC IV01 pin 53, through QV23, QV24, and into the 2-Line Comb
Filter IV02 pin 4. It is separated into it's individual Y/C components.
The Y (Luminance) component of the PinP (Sub) picture is then output pin 15, through QV25, low pass filter XV01, through
QV26, QV28 and back into the Selector IC IV01 pin 49.
The C (Chroma) component of the PinP (Sub) picture is then output pin 13, through QV29, low pass filter XV02, through
QV30, QV32 and back into the Selector IC IV01 pin 51.
From here, the Selector IC IV01 dependant upon the customer's selection, will choose between the separated Y/C from com-
posite or the separated inputs S-In and outputs the Y from pin 56 through QV19, QV20 into the PinP (Sub) Video/Chroma
Processor IY03 pin 4.
The C component from pin 58 through QV21, QV22 into the PinP (Sub) Video/Chroma Processor IY03 pin 19.
IY03 FUNCTION:
The responsibility of IY03 is to now convert the separated Y/C components of the PinP (Sub) picture into a usable format for
the Flex Converter. The Flex Converter FC4 utilizes component inputs Y Pr/Pb or Y Cr/Cb. IY03 outputs only NTSC, so it's
output are Y Cr/Cb. Y from pin 24, Cr from pin 22, and Cb from pin 23.
Y is then routed through QY22 to the connector PST2 pin 29.
Cr is then routed through QY24 to the connector PST2 pin 26.
Cb is then routed through QY23 to the connector PST2 pin 27.
(See the Component Video Signal Path for continuation).
NOTE: The DVI input signal flow is shown in the Component Video Signal Path Circuit Diagram.
NOTE: Models using the DVD Player is also shown in the Component Video Signal Path Circuit Diagram.
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