Toner End Sensor; Mechanism; Near End And End - Ricoh G108 Service Manual

DEVELOPMENT UNIT

6.5.6 TONER END SENSOR

[A]
[B]
[C]
[D]
Arrangement
There are four pairs of photo sensors [A][a][B][b][C][c][D][d]–one pair for each
development unit. Each development unit has a light path window on both of its
sides. The light enters the development unit from the light window on the right side
[G], and then exits from the light window on the left side, so long as the toner is not
full.

Mechanism

A gear [E] in front of the right side light window, called the light interrupter gear, has
openings [F] on its sides. While the gear turns, the light from the right side photo
sensor [a][b][c][d] is intermittently interrupted before passing through the
development unit. The left side sensor [A][B][C][D] receives this pulsing light when
the toner in the development unit is not full.

Near End and End

When the toner is almost empty, the message "Toner is Almost Empty: xxxxx" is
shown, xxxxx is the name of the color, such as cyan or magenta. The development
unit can make approximately 250 images after this message appears. If one of the
color development units (YMC) becomes empty, the machine stops color printing.
Monochrome black printing continues. If the black development unit becomes
empty, the machine stops printing.
NOTE: The figure (250 images) is calculated under these conditions: 1 A4/LT
size, two pages per job,
G108
50% color ratio,
6-22
G108D909.WMF
5% coverage.
[E]
[F]
[G]
[a]
[b]
[c]
[d]
SM