NEC PX-50XM4 series Service Manual page 477

Operational descriptions
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Main side
• The signal out of Video1,2,3, selected with Video SW, is entered in the Video chroma decoder.
• When the entered input is a Composite signal (Video1,2), Y/C separation is carried out in the Video chroma decoder. No Y/C separation is carried out in the case of
an S signal (Video3) input.
• The Y/C-separated signal is converted into a chroma signal in the Video chroma decoder. The converted signal is further digitized.
• The digitized signal input is entered in the digital signal processing block, where various processing of I-P conversion, scaling, γ correction, and others is carried
out.
Sub side
• The chroma signal entered from the DVD/HD2 is output from the out2 side through the Video/sync SW.
• The signal output from out2 passes through the LPF2 and is entered in the A/D2 where it is digitized.
• The digitized signal input is entered in the digital signal processing block, where various processing of I-P conversion, scaling, γ correction, and others is carried
out.
Dual screen synthesis
• The signals processed in Main and Sub respectively are then synthesized in the digital signal processing block.
• After passing through these processes, the signal is entered in the LVDS transmitter and the LVDS signal is generated there. This signal is then applied to the
module.
CONFIDENTIAL
14-19