Ricoh TH-C1b, Руководство по обслуживанию

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10 February 2005 DEVELOPMENT
6-51
D
etailed
D
escr
iptions
6.9.4 TONER END DETECTION
Mechanism
[A]: Optic fiber
[B]: Light emission
[C]: Gap
An optic fiber [A] in each development unit
except the one for black detects toner
end. Light is emitted from the rear end [B]
of the unit. There is a gap [C] in the optic
fiber.
When the development unit is filled with
toner, the toner breaks the light path
through the gap. When the unit is running
out of toner, the light path is not broken.
Toner Near-End Detection
The machine uses two methods simultaneously: pixel count, and toner end sensor.
If either of these methods detects near-end, the machine indicates near-end.
Near-End by Pixel Count (K, C, M, and Y)
The machine counts how many pixels have been printed with each toner cartridge.
When there are 500 prints remaining until the estimated toner end condition, toner
near-end is indicated.
Near-End by Toner End Sensor (C, M, Y only)
•
If the toner end sensor output drops to toner end level, counter 1 is set to 1.
•
If the above condition (counter 1 is 1) is detected twice accumulated 14 seconds
while the development clutch is activated, counter 2 is set to 1.
•
If the above condition (counter 2 is 1) is detected twice continuously, the
machine enters the toner supply mode after the job.
The above detection is carried out while the development clutch is activated.
Toner supply mode after the job:
•
The development unit with the almost-empty cartridge idles for 40 s.
•
Then, it idles again for another 20 s.
•
During this 20 s period, the toner end sensor is checked every 10 ms. If a low
toner condition is detected twice or less during this 20 s period, the machine
returns to standby mode after idling all development units for 90 s.
•
However, if a low toner condition was detected third times or less during that 20 s
period, the machine indicates toner near-end.
B156D303.WMF
[A]
[B] [C]