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Samsung Electronics
¥ +22V Power Controller
If you insert power cords, the main board will be supplied with power. /POR signal put out through reset
circuit activates MFP controller (K32C6200:U15) and MFP controller puts out external circuit reset signal
/RST-OUT. This /RST-OUT signal and Vrefx (+2.5V) divided t30V are impressed to the input ter-
minal of the comparator, putting out +22V if the output of the comparator is ÒhighÓ or getting turned off if
ÒlowÓ.(in case of /FAULT-TEST signal: HIGH) While +22V is being impressed after /RST-OUT is ÒHighÓ,
comparator output gets ÒlowÓ and turns off +22V driving TR(TIP112) if /FAULT-TEST signal is put out at
ÒlowÓ when you check a short of the head driver and the ink cartridge (head).
¥ FAULT TEST CIRCUIT
This is a signal to detect whether the head receiving the output of head column driver is in a short. After
/FAULT-TEST signal is put out at ÒlowÓ and +22V is turned ÒoffÓ, ÒOK2PRINTÓ signal is entered. The port
of KS32C6200(U15) shows normal condition if ÒHÓ and a short if ÒLÓ. If you make FAULT-TEST output ÒLÓ
to detect fault of the head, +22V gets off. If the head is in a short (LOW), when the level of Ò/FAULT-TESTÓ
signal goes ÒLÓ and final ÒOK2PRINTÓ output goes ÒLÓ. KS32C6200(U15) reads this signal and checks
whether the head input receiving the driver output is in a short. Diode cathode is attached to each output
transistor collector in the column driver. 8 anode terminals of diode become common as one and put out
/FAULT signal, which is pulled up by bias circuit controlled by /FAULT-TEST and shows the condition by
OK2PRINT through the comparator.
¥ SUBSTRATE HEAT CIRCUIT
Mono ink cartridge of Babbage head is 600dpi head that uses pigment ink. It is very sensitive to the tem-
perature in and around the cartridge. In particular, the viscosity of ink affects print quality as it is inversely
proportional to temperature by an exponential function. This signal used to compensate it helps you get
equal inking quality by warming the ink chamber in the cartridge with aluminum pattern heater before
starting to print if the surrounding temperature is lower than standard (below 35¡É).(Refer to Timing
Chart.) It sends PRE-HEAT signal through I/O port of CIP1A(Color Image Processor:U17) and supplies
+11.75V.
Mono Head
Fig.5-1-13. Temperature around Mono Head
Pre-Heat if below 35¡c
70°C
35°C
Summary of Contents for SF-4300C
Page 2: ...ELECTRONICS ...