Sony DTV-01, Руководство пользователя

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35
Video Block 2
Overview
The V board is fully shielded and contains the digital signal processing.
The V board is sandwiched in-between the analog A and B boards. All
three of these boards plug into the horizontal G board. The V board has
the following inputs and outputs:
V B o a r d S ig n a l P r o c e s s in g
In p u t ( Y , C r , C b ) O u tp u t ( Y , C r , C b ) P u r p o s e
M a in S ig n a l
C N 5 0 3 / p in s 7 , 9 , 1 1
S u b S ig n a l
C N 5 0 3 / p in s 1 , 3 , 5
D R C p r o c e s s e d
m a in p ic t u r e o r M ID
IC 5 0 6 p r o c e s s e d
tw in v ie w p ic tu r e . S im u la t e s a 9 6 0 - lin e
p ic tu r e fr o m a n a c t iv e
4 8 0 lin e N T S C in p u t
s ig n a l.
S e le c t s o n e ( m a in ) o r
tw o s im u lt a n e o u s ( T w in
V ie w ) p ic tu r e s .
Signal Flow
The main picture signal is applied to both the DRC and MID digital circuitry
for processing:
D ig ita l C ir c u itr y
N a m e P u r p o s e
D R C – D ig ita l R e a lit y C r e a t io n D o u b le s s c a n n in g lin e s a n d p ix e ls
a ft e r m a s s iv e p r e s e n t a n d p r e v io u s
lin e in f o r m a tio n a n a ly s is .
M I D – M u lti I m a g e D r iv e r A c c e p ts b o th 4 8 0 - o r /a n d 9 6 0 - lin e
c o m p o n e n t v id e o im a g e s ( m a in / s u b )
a n d c o n v e r ts th e m in to a t w in
p ic tu r e .
The DRC digital circuitry does more than just double the lines, though that
is the primary objective. There are 525 NTSC interlaced lines input (480
viewable lines) to the DRC and 960i (i = interlaced) lines leaving. It is the
manner in which the extra lines are created that makes the DRC circuit
unique. DRC and MID concept explanations are in the pages that follow.
The main picture signal is input to the MID IC directly. The sub picture
signal is converted to a digital signal by A/D Converter IC607 before be-
coming the other input for the MID IC.
The MID digital circuitry reduces this sub and the main picture to fit on the
screen at the same time. This coexistence feature is called Twin View.
The analog output of the MID IC is low pass filtered by filter 1 to reduce D/
A converter noise. Filter 2 is selected in the Japanese version of this TV
set when there is a computer signal input to that version. In the USA TV,
IC519 is never toggled from the position shown.
Either the main or the Twin View picture is selected by IC528 and this
resultant signal is sent to the next (B) board.