Panasonic TC-L42D2 Technical Manual page 40

D Series Video Signal Process Circuit
The main function of the A board is to select and process one of the incoming video signals. Video inputs 1
and 2, Component Video Input, HDMI inputs 1, 2 and 3, JPEG data from the SD card slot, and the
composite video output of the tuner are all connected to IC8001 for selection. The video input signal can be
in any of the three formats: Video, Y/C, YPbPr .
All analog signals that enter IC8001 undergo analog to digital conversion. Digital television reception of the
tuner is output in the form of an IF (Intermediate Frequency) signal. The transport stream from the tuner
enters the VSB I/F (Interface) section of IC8001 where the video signal is extracted and converted to RGB
data. The output is provided to the Video Input I/F for selection. The JPEG data of the SD card enters the
JPEG I/F section of IC8001 for conversion into RGB data and output to the Video Input I/F circuit. The video
input interface 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. On Screen Display data such as channel numbers, Digital TV closed caption, and picture
adjustments are mixed with the video data. The RGB data is then converted to dual 14 bit LVDS (Low
Voltage Differential Signaling) and output to the LCD panel. IC8001 handles all video applications. It serves
as the controller that monitors all operations of the TV section of the unit.
The T-Con Board receives from the A Board at connector A21/TC05 two 14 Bit LVDS Signals. The serialized
data (LVDS) is then converted to parallel by the ZWEI2 IC. The data is then processed by the timing control
IC (TCON) to convert the RGB data into serial streams (TFT Drive signals) to control the operation of the
LCD panel. The signals enter the LCD panel through connectors TC01 and TC04.
The drivers are mounted on circuit boards to the top and side of the panel. Shift registers and drivers provide
the drive signals to the rows and columns of pixels on the panel. 12V is supplied to the T-Con Board on
connector A21/TC05 from the Main Board.
The TCON IC produces the data that drives the LCD panel.
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