Toner End Sensor; Arrangement; Mechanism; Near End And End - Ricoh G157 Service Manual

DEVELOPMENT UNIT

6.6.6 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 light windows in the two sides. The
light goes into the development unit from the light window in the right side [G].
Then it goes out from the light window in the left side if the toner is not full.

Mechanism

There is a gear [E] in front of the right-side light window. This gear, 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 going
through the development unit. The left-side sensor [A][B][C][D] accepts blinking
light when the toner in the development unit is not full.

Near End and End

"Replace Toner x" shows when the toner is almost empty. "x" is the name of the
color such as cyan and magenta. The development unit can make approximately
250 images after this message shows. The machine stops color prints jobs if one of
the color development units (YMC) gets empty. At this time, the machine still prints
black and white. The machine stops all print jobs when the K development unit gets
empty.
NOTE: The number (250 images) is calculated under these conditions:
•
A4/LT size
•
two pages per job
•
50% color ratio
•
5% coverage.
G157 6-26
G157D933.WMFF
[E]
[F]
[G]
[a]
[b]
[c]
[d]
SM