Video Signal Block Diagram - Panasonic TH-42PX20U Service Update Information

Video Signal Block Diagram

Figure 3
GP6 series plasma panels incorporate two NTSC tuners. The main tuner is used
for primary picture operation. It provides a composite video and a multiplex audio
output. The sub-tuner provides only a video output used for multi picture
functions. The video outputs of the tuners are connected to the input switch IC on
the H Board. The unit also contains three video inputs that are also connected to
the input switch IC. The input switch IC selects one of the 5 video inputs for main
picture operation and another for sub-picture operation. Selection is controlled by
the MPU via the I C Bus (SDA & SCL). These two outputs are then connected to
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the main switch IC.
The panel also contains three component inputs and a DVI or HDMI input
(depending upon the model) that are connected to the main switch. The DVI or
HDMI input connector, connected to the DG Board, outputs the digital signal to
the DVI or HDMI receiver where it undergoes serial to parallel conversion. The
output of the receiver is then converted to a Y, Pb, and Pr component signals
before being applied to the Main switch. The MPU selects one of the 8 inputs for
main picture operation and another for sub-picture operation.
On the DG- Board, the global core IC (GC2M) converts the composite video
signal of the main picture to RGB video signals. The GC2S IC processes the
sub-picture information and combines it with the main picture. It performs
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