Panasonic DP-CL18 Technical Manual page 34

DP-CL18
3.5.9. Print Cartridge Virgin Sensor Circuit
This printer has 2 virgin sensors for black print cartridge and color print cartridge.
· Detecting whether the print cartridge is set in the printer or not.
· Detecting whether the replaced print cartridge is unused or not.
· Resetting the print cartridge counter on when the number of printed sheets is 250.
<Black Print Cartridge Virgin Sensor>
IC1 (CPU) detects the status (unused/not installed) of black print cartridge by the voltage level of signal PIKK inputted into pin
92.
When the print cartridge is replaced, if the voltage of PIKK (pin 92 of IC1) is approximately 1.02V or less :
IC1 (CPU) recognizes the installed print cartridge as an unused print cartridge and sets the print cartridge counter to "0"
automatically. When the number of printed sheets is 250 sheets after a new print cartridge is installed ( when the print cartridge
counter is 250 ), IC1 outputs a high level PIKFUSEK signal from pin 131 of IC14 to transistor Q7 for 50 sec., turning on the
transistor Q7. As a result, transistor Q14 is turned on and +24V power is supplied to the virgin sensor. This opens the fuse
resistor (100Ω). Then, IC1 rechecks whether the voltage of PIKK is approximately 1.02V or less. If so, the counter is reset to
"0". When the counter reaches 250 after being reset, the high level PIKFUSEK signal is outputted from pin 131 of IC14 to open
the fuse resistor again. This is repeated until the fuse resistor is opened. After opening the fuse resistor, the voltage of signal
PIKK becomes 1.02 ~ 2.36V.
When the print cartridge is replaced, if the voltage of PIKK is 1.02 ~ 2.36V :
IC1 does not recognize that the print cartridge is replaced with a new one. IC1 does not reset the print cartridge counter number
to "0" and counts from the current number.
When the voltage of PIKK is approximately 2.36V or more :
IC1 recognizes that the print cartridge is not installed. The user error "PC-Black Not Installed" is displayed on the LCD display.
The color print cartridge virgin sensor circuit functions in the same manner as the black print cartridge virgin sensor circuit.
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