Panasonic KX-MB2230JT

76
KX-MB2230JT/ KX-MB2270JT/ KX-MB2515JT/ KX-MB2545JT/ KX-MB2575JT/ DP-MB310JT
6.12.15. OPC Life Sensor Circuit
1. General
This circuit detects whether the OPC is brand-new or secondhand.
And if Drum cartridge is detected as brand-new, after predetermined printing, Fuse, which is installed inside of the OPC is cut.
After cutting the fuse, the OPC is judged as secondhand, and OPC life counting starts.
This circuit consists of Fuse cut block and OPC type detection block.
2. Circuit diagram
3. Circuit Explanation of Fuse cut block
When IC300_pinK26 is "H", Q600, Q601 and Q602 are turned on. Then current flows F99 through R600/R601. Conse-
quently Fuse is cut within 1 second.
R600 and R601 are supplied to protect Q600 and Q601 from the fuse cut current.
4. Circuit Explanation of OPC type detection block
This block detects whether OPC is brand-new or secondhand.
And also detect if the contact of the terminal is normal or abnormal (contact error).
(1) In case of Brand-new Drum
Since Fuse is not open, resistance between the fuse is approx. 4ohm.
So the voltage level of point A in the above circuit diagram is less than 1V.
As the result, both Q604 and Q605 are turned on.
(2) In case of secondhand OPC
When Fuse is open, resistance between the fuse is determined by the resistance of R99 (220ohm).
Since the resistance of R609 is 120ohm, the voltage level of point A in the above circuit diagram is approx. 3.5V.
Consequently Q605 is turned on and Q604 is turned off.
(3) In case of contact error of the terminal
Since both F99 and R99 are open condition, resistance between the fuse is infinite.
So the voltage level of point A in the above circuit diagram is approx. 5V.
Then both Q604 and Q605 are turned off.
According to the above transistor condition, the logic level of IC300_pinY24 and Y25 are changed as below table.
Thus by checking these 2 signal levels, drum cartridge condition can be detected.
OPC_CNTCT
(IC300_pinY24)
OPC_LIFE
(IC300_pinY25)
OPC status
L L contact error
H L Secondhand
L H (Not used)
H H Brand-new
IC302
IC300
11
Y25
Y24
OPC _Unit
R601
R600
24V
S5V S3.3V
S5V
R99F99
Main Board
OPC Contact Board
1st use Board
Fuse cut block
OPC type detec tion block
Q602
R607
R605
R602
Q600
Q604
R604
R609
D600
CN506
1
5
Q605
R608
R611
R612
CN79
1
5
A
C600
Q601
R603
OPCFUSECUT
OPC_LIFE
OPC_CNTCT