Samsung SF-4500 Service Manual page 49

• SURROUNDING TEMPERATURE SENSOR
DS1621S(DALLAS SEMI.) is applied to read the
temperature around ink cartridge. It is used to get
optimum inking quality by keeping the viscosity of
ink in the cartridge in the specified lerel. The way
to read temperature is similar to EEPROM, con-
trolled by THM-CLK, THM-DATA LINE. Digital
thermometer to check the surrounding temperature
is assembled along with home sensor in the frame
of assembly CR. After each line is inked, it reads
the surrounding temperature and heats substrate
BA
Signal
BP
Signal
Front End Delay
6-18
Fire Enable Timer
Pre-Heat Pulse Width
Pre-Heat Delay Width
Fig.6-1-16. HEAD DRIVING TIMING DIAGRAM
heater in the ink cartridge during the accelerating
time of CR to keep the viscosity of ink in the speci-
fied lerel.
6-1-5-4. HEAD DRIVING TIMING
Control signal from MFP controller (KS32C6200:U16)
enters the head driver (U26, U27, U32, U33) and it
becomes the level to be able to drive the head nozzles
(+11.75V). It is depicted in the following diagram.
t (PD)
p
Fire Pulse Width
Back End Delay
Samsung Electronics