Mitsubishi V19-V21, Tehnical Manual

Page: 46 / 71

7-4
AMDP, Cb-AMDP and Cr-AMDP are directed to the
VCJ.
When the main picture source is a HD Broadcast or
QAM cable signal, the circuitry in the DM Module
processes the signals and outputs the resulting ana-
log RGB signals. The DM RGB signals are applied
to two sets of inputs on the VCJ:
1) DM Main Picture Input
2) OSD Insertion Input
All on screen (OSD) display signals are generated in
the DM Module, except Convergence OSD. When
the main picture source is digital, HD or QAM, OSD
insertion occurs in the DM Module. When the main
picture is an analog signal, RGB OSD signals from
the DM Module are directed to the OSD insertion
inputs on the VCJ and are inserted in the main pic-
ture in the VCJ.
The VCJ processes the selected signals, and converts
them to the RGB format to drive the CRTs.
Sub Picture Signal Path
Sub picture NTSC signals, from the A/V Switch cir-
cuitry, are converted to YCbCr signals by the Sub
Decoder. The output from the Sub Decoder is applied
to the Sub YCbCr Select circuit. Signals from the
COMP-1, COMP-2 and DTV inputs are also directed
to the Sub YCbCr Select circuit.
The selected signals are directed to 2HDW circuitry
for PIP/POP processing, and insertion into the main
picture. The sub picture source must be 480i or it is
not accepted by the 2HDW circuitry.
3DYC and Main Decoder Circuitry
Figure 7-3 illustrates the circuitry on the PCB-3DYC.
This circuitry is also basically the same as in the V17
and V18 chassis. When the main picture source is
NTSC composite video:
• The video signal is input to IC2C00 at pin 88
for Y and C signal separation.
• Y signal is output at pin 84 of IC2C00 and
directed to the NTSC SW, IC2Y01.
• C signal is output at pin 83 and applied to
the Main Decoder, IC2E00.
When the main signal is S-Y/C:
• The C signal still passes through IC2C00 for
noise reduction.