Panasonic TC-32LX70/70, Technical Manual

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Video Process Block Diagram
Video Process Block Diagram
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The main function of the A board is to select and process one of the incoming video signals. Video inputs,
component video Input, and the composite video output of the tuner are all connected to IC3001 for selection. The video
output signal of the switch can be in any of the three formats: Video, Y/C, or Y, Pb, Pr. The selected output enters IC4510,
the HDMI IF Receiver/Decoder IC, for A/D conversion. The comb filter inside IC4510 converts the composite video signal of
the main picture to Y and C (luminance and chrominance) signals. S-Video, which is already Y/C separated, simply passes
through the comb filter. The chrominance data is then applied to the Chroma Demodulator circuit to separate the color signal
into Pb and Pr data. At the completion of this process, the format of the composite or S-Video signal is now the same as a
digital 480i component signal. If the incoming video is in the 480p, 720P, or 1080i format, the Y, Pb, and Pr signals undergo
A/D (analog to digital) conversion only. The 10 bit YUV data is provided to a video switch. The HDMI receiver section of
IC4510 converts the incoming HDMI signals to a YUV video signal. The Video interface circuit selects between the two HDMI
sources and outputs the YUV signal to the switch. The output of the switch is provided to the PEAKS LITE IC, IC8001.
Digital television reception of the tuner is output in the form of a transport stream (CHODATA). The transport
stream enters the DTV I/F (Interface) section of IC8001 where the video signal is extracted and converted to YUV data. The
output is provided to the Video Input switch for selection. The JPEG data of the GS board enters the JPEG I/F section of
IC8001 for conversion into YUV data and output to the video switch. The video switch outputs the selected picture data to the
Video Process circuit.
The Video Process section of the IC performs all picture control operations such as brightness, contrast, color,
tint, etc. The output signal is then applied to the HQ1L circuit (IC4200) for frame doubling operation. IC4200 is the circuit
responsible for the Motion Picture Pro operation that reduces afterimage by 50%. On Screen Display data such as channel
numbers, Digital TV closed caption, and picture adjustments are mixed with the video data. The output of IC4200 is provided
to the LVDS transmitter (IC4207). The transmitter distributes signals with low-jitter, while creating little noise. It reduces
power consumption and the generated noise from data transmission. Another benefit of the LVDS standard is minimal
concern for cable length.
The main MCU (IC1100) controls the entire operation of the A board. It serves as the controller that monitors all
operations of the TV section (not display) of the unit. When watching digital television or viewing pictures from an SD card,
the video process section of IC8001 converts the digital video into analog composite video signal for output at the monitor out
jack.