Table of Contents
Advertisement
2. Color difference signal processor
The Y, R-Y and B-Y signals from the component input terminals are supplied to CN002 pins 20, 16 and 12.
The Y signal goes to pin 13 of the IC305 analog switch.
The 8-Y signal is inverted through the amplifier and buffer circuit of 0361 and 0362 and supplied to IC304 pin 5. The
signal is switched with the pulse cross signal via pin 3 (refer to separate description of the pulse cross and switching
signals). The signal output from pin 4 is sent through buffer 0364 to IC305 pin 3.
The R-Y signal is inverted through the amplifier and buffer circuit of 0331 and 0332 and supplied to IC304 pin 2. The
signal is switched with the pulse cross signal via pin 1. The signal output from pin 15 is sent through buffer 0334 to
IC305 pin 1.
IC305 selects between the Y, -(R-Y) and -(8-Y) color difference signals via the Y/C separate circuit and the component
input terminals. When COMP/-V and YC from the MPU are High level, the signals from the component input terminals
are selected. The selected Y, -(B-Y) and -(R·Y) signal outputs are obtained respectively from pins 14, 4 and 15.
The Y signal is sent through the 0305, 0301 and 0302 amplifier and buffer circuit to IC304 pin 12. The signal is
switched with the cross pulse signal via pin 13. The output signal from pin 14 goes through buffer 0304 to IC401 pin 16.
The timing is delayed to match the -(B-Y) and -(R·Y) color difference signals. The delay amount is variable
by the 12C
bus SDA and SCL. The output from pin 12 is applied to pin 8 of the IC402 video processor. Also, the -(B-Y) is applied
to IC402 pin 6 and the -(R·Y) signal to IC402 pin 7.
IC305
TP-65
FROM
.
INPUT PB
y
y
20
TO
IC501@
R-Y
AMP/BUFFER
-(R-YI
12
Q331,0332
BUFFER
-<R-Yl
TP·R·Y
Q334
•
PULSE
TO
CROSS
IC402{v
CIRCUIT
8-Y
AMP/BUFFER
-(B-YI
16
Q361,Q362
CNOO2
BUFFER
-<
e-v
1
0364
TP-B·Y
•
PULSE
TO
D 1-1v1 I 17.JU I
CROSS
IC402@
CIRCUIT
IC304
AMP/BUFFER
y
Q305,Q301,Q302
BUFFER
TO
0304
IC402@
PULSE
CROSS
CIRCUIT
A
SCL
IC401
Fig. 2-1 Color difference
signal processor
-85-
Hide quick links:
Advertisement
Chapters
Table of Contents
