Sync Interface - NEC MultiSync 3D JC-1404HME Service Manual

(2-3-2) Sync Interface Circuit
(a) The outputs of this circuit are positive H. SYNC. and V. SYNC. for the following inputs:
(i) SEPARATE SYNC POSITIVE/NEGATIVE polarity
(ii) COMPOSITE SYNC POSITIVE/NEGATIVE polarity
(iii)
SYNC. ON GREEN
NEGATIVE polarity
SYNC ONG
0850
SYNC./VIDEO
I
- HJV.SVNC.
r
SEPARATOR
I
SEPARATOR
H. SYNC/COMPOSITE SYNC.
~
0829
-
,,
-
SYNC.
V. SYNC
EXISTENCE
0835
-
DISTINCTION
SYNC.
POLARITY
DISTINCTION
-
-
-
-
H. SYNC (CN-M 3 pin)
V. SYNC (CN-M 4 pin)
-
-
I
I
-
-
-
-
H.P. (CN-M 5
pin)
V.P. (CN-M6 pin)
H.E.
(CN-M 7
pin)
-
V.E.
(CN-M 8
pin)
(Fig. 2-3-2) BLOCK DIAGRAM of the Sync. Interface Circuit
(i) For the separate sync. mode, the horizontal and vertical synchronization signals are
supplied to the SYNC. EXISTENCE DISTINCTION and to the SYNC. POLARITY DIS-
TINCTION circuits. The outputs after these circuits are a positive H. sync. and a negative
V. sync.
(ii) For the composite sync. mode, the composite synchronization signal is applied to the
H./V. SYNC SEPARATOR circuit from the SYNC. EXISTENCE DISTINCTION circuit.
(iii) For the sync. on green a~alog mode, the green signal is applied to the SYNC./VIDEO
SEPARATOR circuit which produces a composite synchronization signal. And then, it
is the same as for the composite sync. mode.
(b) The outputs of the distinction circuit are as follows:
These outputs are applied to IC151 (CPU) on the main PWB.
• TTL/ANALOG Identification signal
(CN-M 5 pin)
• H. SYNC. signals's polarity
(CN-M 6 pin)
• V. SYNC. signal's polarity
(CN-M 7 pin)
• H. SYNC. availability
(CN-M 8 pin)
• V. SYNC. availability
(CN-M 9 pin)
• Mode signal
(CN-M 10 pin)
NOTE:
L ... Low level of TTL
H ... High level of TTL
{
L: ANALOG
H:TTL
{
L: POSITIVE POLARITY
H: NEGATIVE POLARITY
{
L: POSITIVE POLARITY
H: NEGATIVE POLARITY
{
L:NONE
H: AVAILABLE
{
L:NONE
H: AVAILABLE
{
L:NORMAL
H: MDA/USER MODE
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